66 files changed, 2181 insertions, 675 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 330bdd1cb..41b6d4ab4 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -58,9 +58,9 @@ dependencies = [
 
 [[package]]
 name = "backtrace-sys"
-version = "0.1.33"
+version = "0.1.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e17b52e737c40a7d75abca20b29a19a0eb7ba9fc72c5a72dd282a0a3c2c0dc35"
+checksum = "ca797db0057bae1a7aa2eef3283a874695455cecf08a43bfb8507ee0ebc1ed69"
 dependencies = [
  "cc",
  "libc",
@@ -80,9 +80,9 @@ checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 
 [[package]]
 name = "bstr"
-version = "0.2.11"
+version = "0.2.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "502ae1441a0a5adb8fbd38a5955a6416b9493e92b465de5e4a9bde6a539c2c48"
+checksum = "2889e6d50f394968c8bf4240dc3f2a7eb4680844d27308f798229ac9d4725f41"
 dependencies = [
  "memchr",
 ]
@@ -940,6 +940,7 @@ dependencies = [
 name = "ra_hir"
 version = "0.1.0"
 dependencies = [
+ "arrayvec",
  "either",
  "itertools",
  "log",
@@ -1229,9 +1230,9 @@ checksum = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
 
 [[package]]
 name = "regex"
-version = "1.3.4"
+version = "1.3.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "322cf97724bea3ee221b78fe25ac9c46114ebb51747ad5babd51a2fc6a8235a8"
+checksum = "8900ebc1363efa7ea1c399ccc32daed870b4002651e0bed86e72d501ebbe0048"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -1241,9 +1242,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.6.16"
+version = "0.6.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1132f845907680735a84409c3bebc64d1364a5683ffbce899550cd09d5eaefc1"
+checksum = "7fe5bd57d1d7414c6b5ed48563a2c855d995ff777729dcd91c369ec7fea395ae"
 
 [[package]]
 name = "relative-path"
@@ -1341,9 +1342,9 @@ dependencies = [
 
 [[package]]
 name = "ryu"
-version = "1.0.2"
+version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bfa8506c1de11c9c4e4c38863ccbe02a305c8188e85a05a784c9e11e1c3910c8"
+checksum = "535622e6be132bccd223f4bb2b8ac8d53cda3c7a6394944d3b2b33fb974f9d76"
 
 [[package]]
 name = "salsa"
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index 50a15f978..62fadcddd 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -235,7 +235,7 @@ mod helpers {
             (Some(assist), ExpectedResult::Target(target)) => {
                 let action = assist.0[0].action.clone().unwrap();
                 let range = action.target.expect("expected target on action");
-                assert_eq_text!(&before[range.start().to_usize()..range.end().to_usize()], target);
+                assert_eq_text!(&before[range], target);
             }
             (Some(_), ExpectedResult::NotApplicable) => panic!("assist should not be applicable!"),
             (None, ExpectedResult::After(_)) | (None, ExpectedResult::Target(_)) => {
diff --git a/crates/ra_cargo_watch/src/conv.rs b/crates/ra_cargo_watch/src/conv.rs
index 0246adfb5..c6f8ca329 100644
--- a/crates/ra_cargo_watch/src/conv.rs
+++ b/crates/ra_cargo_watch/src/conv.rs
@@ -8,6 +8,7 @@ use lsp_types::{
     Location, NumberOrString, Position, Range, TextEdit, Url, WorkspaceEdit,
 };
 use std::{
+    collections::HashMap,
     fmt::Write,
     path::{Component, Path, PathBuf, Prefix},
     str::FromStr,
@@ -126,44 +127,34 @@ fn map_rust_child_diagnostic(
     rd: &RustDiagnostic,
     workspace_root: &PathBuf,
 ) -> MappedRustChildDiagnostic {
-    let span: &DiagnosticSpan = match rd.spans.iter().find(|s| s.is_primary) {
-        Some(span) => span,
-        None => {
-            // `rustc` uses these spanless children as a way to print multi-line
-            // messages
-            return MappedRustChildDiagnostic::MessageLine(rd.message.clone());
+    let spans: Vec<&DiagnosticSpan> = rd.spans.iter().filter(|s| s.is_primary).collect();
+    if spans.is_empty() {
+        // `rustc` uses these spanless children as a way to print multi-line
+        // messages
+        return MappedRustChildDiagnostic::MessageLine(rd.message.clone());
+    }
+
+    let mut edit_map: HashMap<Url, Vec<TextEdit>> = HashMap::new();
+    for &span in &spans {
+        if let Some(suggested_replacement) = &span.suggested_replacement {
+            let location = map_span_to_location(span, workspace_root);
+            let edit = TextEdit::new(location.range, suggested_replacement.clone());
+            edit_map.entry(location.uri).or_default().push(edit);
         }
-    };
-
-    // If we have a primary span use its location, otherwise use the parent
-    let location = map_span_to_location(&span, workspace_root);
-
-    if let Some(suggested_replacement) = &span.suggested_replacement {
-        // Include our replacement in the title unless it's empty
-        let title = if !suggested_replacement.is_empty() {
-            format!("{}: '{}'", rd.message, suggested_replacement)
-        } else {
-            rd.message.clone()
-        };
-
-        let edit = {
-            let edits = vec![TextEdit::new(location.range, suggested_replacement.clone())];
-            let mut edit_map = std::collections::HashMap::new();
-            edit_map.insert(location.uri, edits);
-            WorkspaceEdit::new(edit_map)
-        };
+    }
 
+    if !edit_map.is_empty() {
         MappedRustChildDiagnostic::SuggestedFix(CodeAction {
-            title,
+            title: rd.message.clone(),
             kind: Some("quickfix".to_string()),
             diagnostics: None,
-            edit: Some(edit),
+            edit: Some(WorkspaceEdit::new(edit_map)),
             command: None,
             is_preferred: None,
         })
     } else {
         MappedRustChildDiagnostic::Related(DiagnosticRelatedInformation {
-            location,
+            location: map_span_to_location(spans[0], workspace_root),
             message: rd.message.clone(),
         })
     }
@@ -189,13 +180,13 @@ pub(crate) struct MappedRustDiagnostic {
 pub(crate) fn map_rust_diagnostic_to_lsp(
     rd: &RustDiagnostic,
     workspace_root: &PathBuf,
-) -> Option<MappedRustDiagnostic> {
-    let primary_span = rd.spans.iter().find(|s| s.is_primary)?;
-
-    let location = map_span_to_location(&primary_span, workspace_root);
+) -> Vec<MappedRustDiagnostic> {
+    let primary_spans: Vec<&DiagnosticSpan> = rd.spans.iter().filter(|s| s.is_primary).collect();
+    if primary_spans.is_empty() {
+        return vec![];
+    }
 
     let severity = map_level_to_severity(rd.level);
-    let mut primary_span_label = primary_span.label.as_ref();
 
     let mut source = String::from("rustc");
     let mut code = rd.code.as_ref().map(|c| c.code.clone());
@@ -208,19 +199,10 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
         }
     }
 
+    let mut needs_primary_span_label = true;
     let mut related_information = vec![];
     let mut tags = vec![];
 
-    // If error occurs from macro expansion, add related info pointing to
-    // where the error originated
-    if !is_from_macro(&primary_span.file_name) && primary_span.expansion.is_some() {
-        let def_loc = map_span_to_location_naive(&primary_span, workspace_root);
-        related_information.push(DiagnosticRelatedInformation {
-            location: def_loc,
-            message: "Error originated from macro here".to_string(),
-        });
-    }
-
     for secondary_span in rd.spans.iter().filter(|s| !s.is_primary) {
         let related = map_secondary_span_to_related(secondary_span, workspace_root);
         if let Some(related) = related {
@@ -240,15 +222,11 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
 
                 // These secondary messages usually duplicate the content of the
                 // primary span label.
-                primary_span_label = None;
+                needs_primary_span_label = false;
             }
         }
     }
 
-    if let Some(primary_span_label) = primary_span_label {
-        write!(&mut message, "\n{}", primary_span_label).unwrap();
-    }
-
     if is_unused_or_unnecessary(rd) {
         tags.push(DiagnosticTag::Unnecessary);
     }
@@ -257,21 +235,45 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
         tags.push(DiagnosticTag::Deprecated);
     }
 
-    let diagnostic = Diagnostic {
-        range: location.range,
-        severity,
-        code: code.map(NumberOrString::String),
-        source: Some(source),
-        message,
-        related_information: if !related_information.is_empty() {
-            Some(related_information)
-        } else {
-            None
-        },
-        tags: if !tags.is_empty() { Some(tags) } else { None },
-    };
-
-    Some(MappedRustDiagnostic { location, diagnostic, fixes })
+    primary_spans
+        .iter()
+        .map(|primary_span| {
+            let location = map_span_to_location(&primary_span, workspace_root);
+
+            let mut message = message.clone();
+            if needs_primary_span_label {
+                if let Some(primary_span_label) = &primary_span.label {
+                    write!(&mut message, "\n{}", primary_span_label).unwrap();
+                }
+            }
+
+            // If error occurs from macro expansion, add related info pointing to
+            // where the error originated
+            if !is_from_macro(&primary_span.file_name) && primary_span.expansion.is_some() {
+                let def_loc = map_span_to_location_naive(&primary_span, workspace_root);
+                related_information.push(DiagnosticRelatedInformation {
+                    location: def_loc,
+                    message: "Error originated from macro here".to_string(),
+                });
+            }
+
+            let diagnostic = Diagnostic {
+                range: location.range,
+                severity,
+                code: code.clone().map(NumberOrString::String),
+                source: Some(source.clone()),
+                message,
+                related_information: if !related_information.is_empty() {
+                    Some(related_information.clone())
+                } else {
+                    None
+                },
+                tags: if !tags.is_empty() { Some(tags.clone()) } else { None },
+            };
+
+            MappedRustDiagnostic { location, diagnostic, fixes: fixes.clone() }
+        })
+        .collect()
 }
 
 /// Returns a `Url` object from a given path, will lowercase drive letters if present.
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_clippy_pass_by_ref.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_clippy_pass_by_ref.snap
index 95ca163dc..9e8f4eff4 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_clippy_pass_by_ref.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_clippy_pass_by_ref.snap
@@ -2,98 +2,100 @@
 source: crates/ra_cargo_watch/src/conv/test.rs
 expression: diag
 ---
-MappedRustDiagnostic {
-    location: Location {
-        uri: "file:///test/compiler/mir/tagset.rs",
-        range: Range {
-            start: Position {
-                line: 41,
-                character: 23,
-            },
-            end: Position {
-                line: 41,
-                character: 28,
+[
+    MappedRustDiagnostic {
+        location: Location {
+            uri: "file:///test/compiler/mir/tagset.rs",
+            range: Range {
+                start: Position {
+                    line: 41,
+                    character: 23,
+                },
+                end: Position {
+                    line: 41,
+                    character: 28,
+                },
             },
         },
-    },
-    diagnostic: Diagnostic {
-        range: Range {
-            start: Position {
-                line: 41,
-                character: 23,
-            },
-            end: Position {
-                line: 41,
-                character: 28,
+        diagnostic: Diagnostic {
+            range: Range {
+                start: Position {
+                    line: 41,
+                    character: 23,
+                },
+                end: Position {
+                    line: 41,
+                    character: 28,
+                },
             },
-        },
-        severity: Some(
-            Warning,
-        ),
-        code: Some(
-            String(
-                "trivially_copy_pass_by_ref",
+            severity: Some(
+                Warning,
             ),
-        ),
-        source: Some(
-            "clippy",
-        ),
-        message: "this argument is passed by reference, but would be more efficient if passed by value\n#[warn(clippy::trivially_copy_pass_by_ref)] implied by #[warn(clippy::all)]\nfor further information visit https://rust-lang.github.io/rust-clippy/master/index.html#trivially_copy_pass_by_ref",
-        related_information: Some(
-            [
-                DiagnosticRelatedInformation {
-                    location: Location {
-                        uri: "file:///test/compiler/lib.rs",
-                        range: Range {
-                            start: Position {
-                                line: 0,
-                                character: 8,
-                            },
-                            end: Position {
-                                line: 0,
-                                character: 19,
+            code: Some(
+                String(
+                    "trivially_copy_pass_by_ref",
+                ),
+            ),
+            source: Some(
+                "clippy",
+            ),
+            message: "this argument is passed by reference, but would be more efficient if passed by value\n#[warn(clippy::trivially_copy_pass_by_ref)] implied by #[warn(clippy::all)]\nfor further information visit https://rust-lang.github.io/rust-clippy/master/index.html#trivially_copy_pass_by_ref",
+            related_information: Some(
+                [
+                    DiagnosticRelatedInformation {
+                        location: Location {
+                            uri: "file:///test/compiler/lib.rs",
+                            range: Range {
+                                start: Position {
+                                    line: 0,
+                                    character: 8,
+                                },
+                                end: Position {
+                                    line: 0,
+                                    character: 19,
+                                },
                             },
                         },
+                        message: "lint level defined here",
                     },
-                    message: "lint level defined here",
-                },
-            ],
-        ),
-        tags: None,
-    },
-    fixes: [
-        CodeAction {
-            title: "consider passing by value instead: \'self\'",
-            kind: Some(
-                "quickfix",
+                ],
             ),
-            diagnostics: None,
-            edit: Some(
-                WorkspaceEdit {
-                    changes: Some(
-                        {
-                            "file:///test/compiler/mir/tagset.rs": [
-                                TextEdit {
-                                    range: Range {
-                                        start: Position {
-                                            line: 41,
-                                            character: 23,
-                                        },
-                                        end: Position {
-                                            line: 41,
-                                            character: 28,
+            tags: None,
+        },
+        fixes: [
+            CodeAction {
+                title: "consider passing by value instead",
+                kind: Some(
+                    "quickfix",
+                ),
+                diagnostics: None,
+                edit: Some(
+                    WorkspaceEdit {
+                        changes: Some(
+                            {
+                                "file:///test/compiler/mir/tagset.rs": [
+                                    TextEdit {
+                                        range: Range {
+                                            start: Position {
+                                                line: 41,
+                                                character: 23,
+                                            },
+                                            end: Position {
+                                                line: 41,
+                                                character: 28,
+                                            },
                                         },
+                                        new_text: "self",
                                     },
-                                    new_text: "self",
-                                },
-                            ],
-                        },
-                    ),
-                    document_changes: None,
-                },
-            ),
-            command: None,
-            is_preferred: None,
-        },
-    ],
-}
+                                ],
+                            },
+                        ),
+                        document_changes: None,
+                    },
+                ),
+                command: None,
+                is_preferred: None,
+            },
+        ],
+    },
+]
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_handles_macro_location.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_handles_macro_location.snap
index 12eb32df4..61ae0c9ae 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_handles_macro_location.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_handles_macro_location.snap
@@ -2,45 +2,47 @@
 source: crates/ra_cargo_watch/src/conv/test.rs
 expression: diag
 ---
-MappedRustDiagnostic {
-    location: Location {
-        uri: "file:///test/src/main.rs",
-        range: Range {
-            start: Position {
-                line: 1,
-                character: 4,
-            },
-            end: Position {
-                line: 1,
-                character: 26,
+[
+    MappedRustDiagnostic {
+        location: Location {
+            uri: "file:///test/src/main.rs",
+            range: Range {
+                start: Position {
+                    line: 1,
+                    character: 4,
+                },
+                end: Position {
+                    line: 1,
+                    character: 26,
+                },
             },
         },
-    },
-    diagnostic: Diagnostic {
-        range: Range {
-            start: Position {
-                line: 1,
-                character: 4,
+        diagnostic: Diagnostic {
+            range: Range {
+                start: Position {
+                    line: 1,
+                    character: 4,
+                },
+                end: Position {
+                    line: 1,
+                    character: 26,
+                },
             },
-            end: Position {
-                line: 1,
-                character: 26,
-            },
-        },
-        severity: Some(
-            Error,
-        ),
-        code: Some(
-            String(
-                "E0277",
+            severity: Some(
+                Error,
             ),
-        ),
-        source: Some(
-            "rustc",
-        ),
-        message: "can\'t compare `{integer}` with `&str`\nthe trait `std::cmp::PartialEq<&str>` is not implemented for `{integer}`",
-        related_information: None,
-        tags: None,
+            code: Some(
+                String(
+                    "E0277",
+                ),
+            ),
+            source: Some(
+                "rustc",
+            ),
+            message: "can\'t compare `{integer}` with `&str`\nthe trait `std::cmp::PartialEq<&str>` is not implemented for `{integer}`",
+            related_information: None,
+            tags: None,
+        },
+        fixes: [],
     },
-    fixes: [],
-}
+]
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_macro_compiler_error.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_macro_compiler_error.snap
index 7b83a7cd0..641da1a58 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_macro_compiler_error.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_macro_compiler_error.snap
@@ -2,60 +2,62 @@
 source: crates/ra_cargo_watch/src/conv/test.rs
 expression: diag
 ---
-MappedRustDiagnostic {
-    location: Location {
-        uri: "file:///test/crates/ra_hir_def/src/data.rs",
-        range: Range {
-            start: Position {
-                line: 79,
-                character: 15,
-            },
-            end: Position {
-                line: 79,
-                character: 41,
+[
+    MappedRustDiagnostic {
+        location: Location {
+            uri: "file:///test/crates/ra_hir_def/src/data.rs",
+            range: Range {
+                start: Position {
+                    line: 79,
+                    character: 15,
+                },
+                end: Position {
+                    line: 79,
+                    character: 41,
+                },
             },
         },
-    },
-    diagnostic: Diagnostic {
-        range: Range {
-            start: Position {
-                line: 79,
-                character: 15,
-            },
-            end: Position {
-                line: 79,
-                character: 41,
+        diagnostic: Diagnostic {
+            range: Range {
+                start: Position {
+                    line: 79,
+                    character: 15,
+                },
+                end: Position {
+                    line: 79,
+                    character: 41,
+                },
             },
-        },
-        severity: Some(
-            Error,
-        ),
-        code: None,
-        source: Some(
-            "rustc",
-        ),
-        message: "Please register your known path in the path module",
-        related_information: Some(
-            [
-                DiagnosticRelatedInformation {
-                    location: Location {
-                        uri: "file:///test/crates/ra_hir_def/src/path.rs",
-                        range: Range {
-                            start: Position {
-                                line: 264,
-                                character: 8,
-                            },
-                            end: Position {
-                                line: 264,
-                                character: 76,
+            severity: Some(
+                Error,
+            ),
+            code: None,
+            source: Some(
+                "rustc",
+            ),
+            message: "Please register your known path in the path module",
+            related_information: Some(
+                [
+                    DiagnosticRelatedInformation {
+                        location: Location {
+                            uri: "file:///test/crates/ra_hir_def/src/path.rs",
+                            range: Range {
+                                start: Position {
+                                    line: 264,
+                                    character: 8,
+                                },
+                                end: Position {
+                                    line: 264,
+                                    character: 76,
+                                },
                             },
                         },
+                        message: "Error originated from macro here",
                     },
-                    message: "Error originated from macro here",
-                },
-            ],
-        ),
-        tags: None,
+                ],
+            ),
+            tags: None,
+        },
+        fixes: [],
     },
-    fixes: [],
-}
+]
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_multi_line_fix.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_multi_line_fix.snap
new file mode 100644
index 000000000..0557a2e79
--- /dev/null
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_multi_line_fix.snap
@@ -0,0 +1,114 @@
+---
+source: crates/ra_cargo_watch/src/conv/test.rs
+expression: diag
+---
+[
+    MappedRustDiagnostic {
+        location: Location {
+            uri: "file:///test/src/main.rs",
+            range: Range {
+                start: Position {
+                    line: 3,
+                    character: 4,
+                },
+                end: Position {
+                    line: 3,
+                    character: 5,
+                },
+            },
+        },
+        diagnostic: Diagnostic {
+            range: Range {
+                start: Position {
+                    line: 3,
+                    character: 4,
+                },
+                end: Position {
+                    line: 3,
+                    character: 5,
+                },
+            },
+            severity: Some(
+                Warning,
+            ),
+            code: Some(
+                String(
+                    "let_and_return",
+                ),
+            ),
+            source: Some(
+                "clippy",
+            ),
+            message: "returning the result of a let binding from a block\n`#[warn(clippy::let_and_return)]` on by default\nfor further information visit https://rust-lang.github.io/rust-clippy/master/index.html#let_and_return",
+            related_information: Some(
+                [
+                    DiagnosticRelatedInformation {
+                        location: Location {
+                            uri: "file:///test/src/main.rs",
+                            range: Range {
+                                start: Position {
+                                    line: 2,
+                                    character: 4,
+                                },
+                                end: Position {
+                                    line: 2,
+                                    character: 30,
+                                },
+                            },
+                        },
+                        message: "unnecessary let binding",
+                    },
+                ],
+            ),
+            tags: None,
+        },
+        fixes: [
+            CodeAction {
+                title: "return the expression directly",
+                kind: Some(
+                    "quickfix",
+                ),
+                diagnostics: None,
+                edit: Some(
+                    WorkspaceEdit {
+                        changes: Some(
+                            {
+                                "file:///test/src/main.rs": [
+                                    TextEdit {
+                                        range: Range {
+                                            start: Position {
+                                                line: 2,
+                                                character: 4,
+                                            },
+                                            end: Position {
+                                                line: 2,
+                                                character: 30,
+                                            },
+                                        },
+                                        new_text: "",
+                                    },
+                                    TextEdit {
+                                        range: Range {
+                                            start: Position {
+                                                line: 3,
+                                                character: 4,
+                                            },
+                                            end: Position {
+                                                line: 3,
+                                                character: 5,
+                                            },
+                                        },
+                                        new_text: "(0..10).collect()",
+                                    },
+                                ],
+                            },
+                        ),
+                        document_changes: None,
+                    },
+                ),
+                command: None,
+                is_preferred: None,
+            },
+        ],
+    },
+]
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_incompatible_type_for_trait.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_incompatible_type_for_trait.snap
index 54679c5db..754bc33a4 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_incompatible_type_for_trait.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_incompatible_type_for_trait.snap
@@ -2,45 +2,47 @@
 source: crates/ra_cargo_watch/src/conv/test.rs
 expression: diag
 ---
-MappedRustDiagnostic {
-    location: Location {
-        uri: "file:///test/compiler/ty/list_iter.rs",
-        range: Range {
-            start: Position {
-                line: 51,
-                character: 4,
-            },
-            end: Position {
-                line: 51,
-                character: 47,
+[
+    MappedRustDiagnostic {
+        location: Location {
+            uri: "file:///test/compiler/ty/list_iter.rs",
+            range: Range {
+                start: Position {
+                    line: 51,
+                    character: 4,
+                },
+                end: Position {
+                    line: 51,
+                    character: 47,
+                },
             },
         },
-    },
-    diagnostic: Diagnostic {
-        range: Range {
-            start: Position {
-                line: 51,
-                character: 4,
+        diagnostic: Diagnostic {
+            range: Range {
+                start: Position {
+                    line: 51,
+                    character: 4,
+                },
+                end: Position {
+                    line: 51,
+                    character: 47,
+                },
             },
-            end: Position {
-                line: 51,
-                character: 47,
-            },
-        },
-        severity: Some(
-            Error,
-        ),
-        code: Some(
-            String(
-                "E0053",
+            severity: Some(
+                Error,
             ),
-        ),
-        source: Some(
-            "rustc",
-        ),
-        message: "method `next` has an incompatible type for trait\nexpected type `fn(&mut ty::list_iter::ListIterator<\'list, M>) -> std::option::Option<&ty::Ref<M>>`\n   found type `fn(&ty::list_iter::ListIterator<\'list, M>) -> std::option::Option<&\'list ty::Ref<M>>`",
-        related_information: None,
-        tags: None,
+            code: Some(
+                String(
+                    "E0053",
+                ),
+            ),
+            source: Some(
+                "rustc",
+            ),
+            message: "method `next` has an incompatible type for trait\nexpected type `fn(&mut ty::list_iter::ListIterator<\'list, M>) -> std::option::Option<&ty::Ref<M>>`\n   found type `fn(&ty::list_iter::ListIterator<\'list, M>) -> std::option::Option<&\'list ty::Ref<M>>`",
+            related_information: None,
+            tags: None,
+        },
+        fixes: [],
     },
-    fixes: [],
-}
+]
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_mismatched_type.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_mismatched_type.snap
index 57df4ceaf..78b7f7cc8 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_mismatched_type.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_mismatched_type.snap
@@ -2,45 +2,47 @@
 source: crates/ra_cargo_watch/src/conv/test.rs
 expression: diag
 ---
-MappedRustDiagnostic {
-    location: Location {
-        uri: "file:///test/runtime/compiler_support.rs",
-        range: Range {
-            start: Position {
-                line: 47,
-                character: 64,
-            },
-            end: Position {
-                line: 47,
-                character: 69,
+[
+    MappedRustDiagnostic {
+        location: Location {
+            uri: "file:///test/runtime/compiler_support.rs",
+            range: Range {
+                start: Position {
+                    line: 47,
+                    character: 64,
+                },
+                end: Position {
+                    line: 47,
+                    character: 69,
+                },
             },
         },
-    },
-    diagnostic: Diagnostic {
-        range: Range {
-            start: Position {
-                line: 47,
-                character: 64,
+        diagnostic: Diagnostic {
+            range: Range {
+                start: Position {
+                    line: 47,
+                    character: 64,
+                },
+                end: Position {
+                    line: 47,
+                    character: 69,
+                },
             },
-            end: Position {
-                line: 47,
-                character: 69,
-            },
-        },
-        severity: Some(
-            Error,
-        ),
-        code: Some(
-            String(
-                "E0308",
+            severity: Some(
+                Error,
             ),
-        ),
-        source: Some(
-            "rustc",
-        ),
-        message: "mismatched types\nexpected usize, found u32",
-        related_information: None,
-        tags: None,
+            code: Some(
+                String(
+                    "E0308",
+                ),
+            ),
+            source: Some(
+                "rustc",
+            ),
+            message: "mismatched types\nexpected usize, found u32",
+            related_information: None,
+            tags: None,
+        },
+        fixes: [],
     },
-    fixes: [],
-}
+]
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_unused_variable.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_unused_variable.snap
index 3e1fe736c..5989ed202 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_unused_variable.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_unused_variable.snap
@@ -2,83 +2,85 @@
 source: crates/ra_cargo_watch/src/conv/test.rs
 expression: diag
 ---
-MappedRustDiagnostic {
-    location: Location {
-        uri: "file:///test/driver/subcommand/repl.rs",
-        range: Range {
-            start: Position {
-                line: 290,
-                character: 8,
-            },
-            end: Position {
-                line: 290,
-                character: 11,
+[
+    MappedRustDiagnostic {
+        location: Location {
+            uri: "file:///test/driver/subcommand/repl.rs",
+            range: Range {
+                start: Position {
+                    line: 290,
+                    character: 8,
+                },
+                end: Position {
+                    line: 290,
+                    character: 11,
+                },
             },
         },
-    },
-    diagnostic: Diagnostic {
-        range: Range {
-            start: Position {
-                line: 290,
-                character: 8,
-            },
-            end: Position {
-                line: 290,
-                character: 11,
+        diagnostic: Diagnostic {
+            range: Range {
+                start: Position {
+                    line: 290,
+                    character: 8,
+                },
+                end: Position {
+                    line: 290,
+                    character: 11,
+                },
             },
-        },
-        severity: Some(
-            Warning,
-        ),
-        code: Some(
-            String(
-                "unused_variables",
+            severity: Some(
+                Warning,
             ),
-        ),
-        source: Some(
-            "rustc",
-        ),
-        message: "unused variable: `foo`\n#[warn(unused_variables)] on by default",
-        related_information: None,
-        tags: Some(
-            [
-                Unnecessary,
-            ],
-        ),
-    },
-    fixes: [
-        CodeAction {
-            title: "consider prefixing with an underscore: \'_foo\'",
-            kind: Some(
-                "quickfix",
+            code: Some(
+                String(
+                    "unused_variables",
+                ),
             ),
-            diagnostics: None,
-            edit: Some(
-                WorkspaceEdit {
-                    changes: Some(
-                        {
-                            "file:///test/driver/subcommand/repl.rs": [
-                                TextEdit {
-                                    range: Range {
-                                        start: Position {
-                                            line: 290,
-                                            character: 8,
-                                        },
-                                        end: Position {
-                                            line: 290,
-                                            character: 11,
-                                        },
-                                    },
-                                    new_text: "_foo",
-                                },
-                            ],
-                        },
-                    ),
-                    document_changes: None,
-                },
+            source: Some(
+                "rustc",
+            ),
+            message: "unused variable: `foo`\n#[warn(unused_variables)] on by default",
+            related_information: None,
+            tags: Some(
+                [
+                    Unnecessary,
+                ],
             ),
-            command: None,
-            is_preferred: None,
         },
-    ],
-}
+        fixes: [
+            CodeAction {
+                title: "consider prefixing with an underscore",
+                kind: Some(
+                    "quickfix",
+                ),
+                diagnostics: None,
+                edit: Some(
+                    WorkspaceEdit {
+                        changes: Some(
+                            {
+                                "file:///test/driver/subcommand/repl.rs": [
+                                    TextEdit {
+                                        range: Range {
+                                            start: Position {
+                                                line: 290,
+                                                character: 8,
+                                            },
+                                            end: Position {
+                                                line: 290,
+                                                character: 11,
+                                            },
+                                        },
+                                        new_text: "_foo",
+                                    },
+                                ],
+                            },
+                        ),
+                        document_changes: None,
+                    },
+                ),
+                command: None,
+                is_preferred: None,
+            },
+        ],
+    },
+]
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_wrong_number_of_parameters.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_wrong_number_of_parameters.snap
index 69301078d..e34b546dc 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_wrong_number_of_parameters.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_wrong_number_of_parameters.snap
@@ -2,64 +2,66 @@
 source: crates/ra_cargo_watch/src/conv/test.rs
 expression: diag
 ---
-MappedRustDiagnostic {
-    location: Location {
-        uri: "file:///test/compiler/ty/select.rs",
-        range: Range {
-            start: Position {
-                line: 103,
-                character: 17,
-            },
-            end: Position {
-                line: 103,
-                character: 29,
+[
+    MappedRustDiagnostic {
+        location: Location {
+            uri: "file:///test/compiler/ty/select.rs",
+            range: Range {
+                start: Position {
+                    line: 103,
+                    character: 17,
+                },
+                end: Position {
+                    line: 103,
+                    character: 29,
+                },
             },
         },
-    },
-    diagnostic: Diagnostic {
-        range: Range {
-            start: Position {
-                line: 103,
-                character: 17,
-            },
-            end: Position {
-                line: 103,
-                character: 29,
+        diagnostic: Diagnostic {
+            range: Range {
+                start: Position {
+                    line: 103,
+                    character: 17,
+                },
+                end: Position {
+                    line: 103,
+                    character: 29,
+                },
             },
-        },
-        severity: Some(
-            Error,
-        ),
-        code: Some(
-            String(
-                "E0061",
+            severity: Some(
+                Error,
             ),
-        ),
-        source: Some(
-            "rustc",
-        ),
-        message: "this function takes 2 parameters but 3 parameters were supplied\nexpected 2 parameters",
-        related_information: Some(
-            [
-                DiagnosticRelatedInformation {
-                    location: Location {
-                        uri: "file:///test/compiler/ty/select.rs",
-                        range: Range {
-                            start: Position {
-                                line: 218,
-                                character: 4,
-                            },
-                            end: Position {
-                                line: 230,
-                                character: 5,
+            code: Some(
+                String(
+                    "E0061",
+                ),
+            ),
+            source: Some(
+                "rustc",
+            ),
+            message: "this function takes 2 parameters but 3 parameters were supplied\nexpected 2 parameters",
+            related_information: Some(
+                [
+                    DiagnosticRelatedInformation {
+                        location: Location {
+                            uri: "file:///test/compiler/ty/select.rs",
+                            range: Range {
+                                start: Position {
+                                    line: 218,
+                                    character: 4,
+                                },
+                                end: Position {
+                                    line: 230,
+                                    character: 5,
+                                },
                             },
                         },
+                        message: "defined here",
                     },
-                    message: "defined here",
-                },
-            ],
-        ),
-        tags: None,
+                ],
+            ),
+            tags: None,
+        },
+        fixes: [],
     },
-    fixes: [],
-}
+]
diff --git a/crates/ra_cargo_watch/src/conv/test.rs b/crates/ra_cargo_watch/src/conv/test.rs
index 6b86525b8..4e81455ca 100644
--- a/crates/ra_cargo_watch/src/conv/test.rs
+++ b/crates/ra_cargo_watch/src/conv/test.rs
@@ -58,7 +58,7 @@ fn snap_rustc_incompatible_type_for_trait() {
     );
 
     let workspace_root = PathBuf::from("/test/");
-    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root).expect("couldn't map diagnostic");
+    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root);
     insta::assert_debug_snapshot!(diag);
 }
 
@@ -141,7 +141,7 @@ fn snap_rustc_unused_variable() {
     );
 
     let workspace_root = PathBuf::from("/test/");
-    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root).expect("couldn't map diagnostic");
+    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root);
     insta::assert_debug_snapshot!(diag);
 }
 
@@ -266,7 +266,7 @@ fn snap_rustc_wrong_number_of_parameters() {
     );
 
     let workspace_root = PathBuf::from("/test/");
-    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root).expect("couldn't map diagnostic");
+    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root);
     insta::assert_debug_snapshot!(diag);
 }
 
@@ -387,7 +387,7 @@ fn snap_clippy_pass_by_ref() {
     );
 
     let workspace_root = PathBuf::from("/test/");
-    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root).expect("couldn't map diagnostic");
+    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root);
     insta::assert_debug_snapshot!(diag);
 }
 
@@ -431,7 +431,7 @@ fn snap_rustc_mismatched_type() {
     );
 
     let workspace_root = PathBuf::from("/test/");
-    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root).expect("couldn't map diagnostic");
+    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root);
     insta::assert_debug_snapshot!(diag);
 }
 
@@ -703,7 +703,7 @@ fn snap_handles_macro_location() {
     );
 
     let workspace_root = PathBuf::from("/test/");
-    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root).expect("couldn't map diagnostic");
+    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root);
     insta::assert_debug_snapshot!(diag);
 }
 
@@ -933,6 +933,140 @@ fn snap_macro_compiler_error() {
     );
 
     let workspace_root = PathBuf::from("/test/");
-    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root).expect("couldn't map diagnostic");
+    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root);
+    insta::assert_debug_snapshot!(diag);
+}
+
+#[test]
+#[cfg(not(windows))]
+fn snap_multi_line_fix() {
+    let diag = parse_diagnostic(
+        r##"{
+            "rendered": "warning: returning the result of a let binding from a block\n --> src/main.rs:4:5\n  |\n3 |     let a = (0..10).collect();\n  |     -------------------------- unnecessary let binding\n4 |     a\n  |     ^\n  |\n  = note: `#[warn(clippy::let_and_return)]` on by default\n  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#let_and_return\nhelp: return the expression directly\n  |\n3 |     \n4 |     (0..10).collect()\n  |\n\n",
+            "children": [
+                {
+                "children": [],
+                "code": null,
+                "level": "note",
+                "message": "`#[warn(clippy::let_and_return)]` on by default",
+                "rendered": null,
+                "spans": []
+                },
+                {
+                "children": [],
+                "code": null,
+                "level": "help",
+                "message": "for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#let_and_return",
+                "rendered": null,
+                "spans": []
+                },
+                {
+                "children": [],
+                "code": null,
+                "level": "help",
+                "message": "return the expression directly",
+                "rendered": null,
+                "spans": [
+                    {
+                    "byte_end": 55,
+                    "byte_start": 29,
+                    "column_end": 31,
+                    "column_start": 5,
+                    "expansion": null,
+                    "file_name": "src/main.rs",
+                    "is_primary": true,
+                    "label": null,
+                    "line_end": 3,
+                    "line_start": 3,
+                    "suggested_replacement": "",
+                    "suggestion_applicability": "MachineApplicable",
+                    "text": [
+                        {
+                        "highlight_end": 31,
+                        "highlight_start": 5,
+                        "text": "    let a = (0..10).collect();"
+                        }
+                    ]
+                    },
+                    {
+                    "byte_end": 61,
+                    "byte_start": 60,
+                    "column_end": 6,
+                    "column_start": 5,
+                    "expansion": null,
+                    "file_name": "src/main.rs",
+                    "is_primary": true,
+                    "label": null,
+                    "line_end": 4,
+                    "line_start": 4,
+                    "suggested_replacement": "(0..10).collect()",
+                    "suggestion_applicability": "MachineApplicable",
+                    "text": [
+                        {
+                        "highlight_end": 6,
+                        "highlight_start": 5,
+                        "text": "    a"
+                        }
+                    ]
+                    }
+                ]
+                }
+            ],
+            "code": {
+                "code": "clippy::let_and_return",
+                "explanation": null
+            },
+            "level": "warning",
+            "message": "returning the result of a let binding from a block",
+            "spans": [
+                {
+                "byte_end": 55,
+                "byte_start": 29,
+                "column_end": 31,
+                "column_start": 5,
+                "expansion": null,
+                "file_name": "src/main.rs",
+                "is_primary": false,
+                "label": "unnecessary let binding",
+                "line_end": 3,
+                "line_start": 3,
+                "suggested_replacement": null,
+                "suggestion_applicability": null,
+                "text": [
+                    {
+                    "highlight_end": 31,
+                    "highlight_start": 5,
+                    "text": "    let a = (0..10).collect();"
+                    }
+                ]
+                },
+                {
+                "byte_end": 61,
+                "byte_start": 60,
+                "column_end": 6,
+                "column_start": 5,
+                "expansion": null,
+                "file_name": "src/main.rs",
+                "is_primary": true,
+                "label": null,
+                "line_end": 4,
+                "line_start": 4,
+                "suggested_replacement": null,
+                "suggestion_applicability": null,
+                "text": [
+                    {
+                    "highlight_end": 6,
+                    "highlight_start": 5,
+                    "text": "    a"
+                    }
+                ]
+                }
+            ]
+        }
+        "##,
+    );
+
+    let workspace_root = PathBuf::from("/test/");
+    let diag = map_rust_diagnostic_to_lsp(&diag, &workspace_root);
     insta::assert_debug_snapshot!(diag);
 }
diff --git a/crates/ra_cargo_watch/src/lib.rs b/crates/ra_cargo_watch/src/lib.rs
index f07c34549..94b9c03d0 100644
--- a/crates/ra_cargo_watch/src/lib.rs
+++ b/crates/ra_cargo_watch/src/lib.rs
@@ -197,23 +197,23 @@ impl CheckWatcherThread {
             }
 
             CheckEvent::Msg(Message::CompilerMessage(msg)) => {
-                let map_result =
-                    match map_rust_diagnostic_to_lsp(&msg.message, &self.workspace_root) {
-                        Some(map_result) => map_result,
-                        None => return,
-                    };
-
-                let MappedRustDiagnostic { location, diagnostic, fixes } = map_result;
-                let fixes = fixes
-                    .into_iter()
-                    .map(|fix| {
-                        CodeAction { diagnostics: Some(vec![diagnostic.clone()]), ..fix }.into()
-                    })
-                    .collect();
+                let map_result = map_rust_diagnostic_to_lsp(&msg.message, &self.workspace_root);
+                if map_result.is_empty() {
+                    return;
+                }
 
-                task_send
-                    .send(CheckTask::AddDiagnostic { url: location.uri, diagnostic, fixes })
-                    .unwrap();
+                for MappedRustDiagnostic { location, diagnostic, fixes } in map_result {
+                    let fixes = fixes
+                        .into_iter()
+                        .map(|fix| {
+                            CodeAction { diagnostics: Some(vec![diagnostic.clone()]), ..fix }.into()
+                        })
+                        .collect();
+
+                    task_send
+                        .send(CheckTask::AddDiagnostic { url: location.uri, diagnostic, fixes })
+                        .unwrap();
+                }
             }
 
             CheckEvent::Msg(Message::BuildScriptExecuted(_msg)) => {}
diff --git a/crates/ra_hir/Cargo.toml b/crates/ra_hir/Cargo.toml
index 266c4cff3..42193b492 100644
--- a/crates/ra_hir/Cargo.toml
+++ b/crates/ra_hir/Cargo.toml
@@ -11,6 +11,7 @@ doctest = false
 log = "0.4.8"
 rustc-hash = "1.1.0"
 either = "1.5.3"
+arrayvec = "0.5.1"
 
 itertools = "0.8.2"
 
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 41d4e2ed3..ff041150b 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -1,6 +1,7 @@
 //! FIXME: write short doc here
 use std::sync::Arc;
 
+use arrayvec::ArrayVec;
 use either::Either;
 use hir_def::{
     adt::StructKind,
@@ -226,7 +227,9 @@ impl Module {
                     Some((name, def))
                 }
             })
-            .map(|(name, def)| (name.clone(), def.into()))
+            .flat_map(|(name, def)| {
+                ScopeDef::all_items(def).into_iter().map(move |item| (name.clone(), item))
+            })
             .collect()
     }
 
@@ -308,7 +311,11 @@ impl StructField {
         self.parent.variant_data(db).fields()[self.id].name.clone()
     }
 
-    pub fn ty(&self, db: &impl HirDatabase) -> Type {
+    /// Returns the type as in the signature of the struct (i.e., with
+    /// placeholder types for type parameters). This is good for showing
+    /// signature help, but not so good to actually get the type of the field
+    /// when you actually have a variable of the struct.
+    pub fn signature_ty(&self, db: &impl HirDatabase) -> Type {
         let var_id = self.parent.into();
         let generic_def_id: GenericDefId = match self.parent {
             VariantDef::Struct(it) => it.id.into(),
@@ -482,6 +489,10 @@ impl Adt {
         let subst = db.generic_defaults(self.into());
         subst.iter().any(|ty| ty == &Ty::Unknown)
     }
+
+    /// Turns this ADT into a type. Any type parameters of the ADT will be
+    /// turned into unknown types, which is good for e.g. finding the most
+    /// general set of completions, but will not look very nice when printed.
     pub fn ty(self, db: &impl HirDatabase) -> Type {
         let id = AdtId::from(self);
         Type::from_def(db, id.module(db).krate, id)
@@ -1028,7 +1039,7 @@ impl Type {
         krate: CrateId,
         def: impl HasResolver + Into<TyDefId> + Into<GenericDefId>,
     ) -> Type {
-        let substs = Substs::type_params(db, def);
+        let substs = Substs::build_for_def(db, def).fill_with_unknown().build();
         let ty = db.ty(def.into()).subst(&substs);
         Type::new(db, krate, def, ty)
     }
@@ -1288,15 +1299,36 @@ pub enum ScopeDef {
     Unknown,
 }
 
-impl From<PerNs> for ScopeDef {
-    fn from(def: PerNs) -> Self {
-        def.take_types()
-            .or_else(|| def.take_values())
-            .map(|module_def_id| ScopeDef::ModuleDef(module_def_id.into()))
-            .or_else(|| {
-                def.take_macros().map(|macro_def_id| ScopeDef::MacroDef(macro_def_id.into()))
-            })
-            .unwrap_or(ScopeDef::Unknown)
+impl ScopeDef {
+    pub fn all_items(def: PerNs) -> ArrayVec<[Self; 3]> {
+        let mut items = ArrayVec::new();
+
+        match (def.take_types(), def.take_values()) {
+            (Some(m1), None) => items.push(ScopeDef::ModuleDef(m1.into())),
+            (None, Some(m2)) => items.push(ScopeDef::ModuleDef(m2.into())),
+            (Some(m1), Some(m2)) => {
+                // Some items, like unit structs and enum variants, are
+                // returned as both a type and a value. Here we want
+                // to de-duplicate them.
+                if m1 != m2 {
+                    items.push(ScopeDef::ModuleDef(m1.into()));
+                    items.push(ScopeDef::ModuleDef(m2.into()));
+                } else {
+                    items.push(ScopeDef::ModuleDef(m1.into()));
+                }
+            }
+            (None, None) => {}
+        };
+
+        if let Some(macro_def_id) = def.take_macros() {
+            items.push(ScopeDef::MacroDef(macro_def_id.into()));
+        }
+
+        if items.is_empty() {
+            items.push(ScopeDef::Unknown);
+        }
+
+        items
     }
 }
 
diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index 3782a9984..788bb3eb7 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -344,7 +344,13 @@ impl<'a, DB: HirDatabase> SemanticsScope<'a, DB> {
 
         resolver.process_all_names(self.db, &mut |name, def| {
             let def = match def {
-                resolver::ScopeDef::PerNs(it) => it.into(),
+                resolver::ScopeDef::PerNs(it) => {
+                    let items = ScopeDef::all_items(it);
+                    for item in items {
+                        f(name.clone(), item);
+                    }
+                    return;
+                }
                 resolver::ScopeDef::ImplSelfType(it) => ScopeDef::ImplSelfType(it.into()),
                 resolver::ScopeDef::AdtSelfType(it) => ScopeDef::AdtSelfType(it.into()),
                 resolver::ScopeDef::GenericParam(id) => ScopeDef::GenericParam(TypeParam { id }),
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index d0459d9b0..db9838cb5 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -102,6 +102,7 @@ struct MacroDirective {
     module_id: LocalModuleId,
     ast_id: AstIdWithPath<ast::MacroCall>,
     legacy: Option<MacroCallId>,
+    depth: usize,
 }
 
 #[derive(Clone, Debug, Eq, PartialEq)]
@@ -134,6 +135,7 @@ where
         self.def_map.modules[module_id].origin = ModuleOrigin::CrateRoot { definition: file_id };
         ModCollector {
             def_collector: &mut *self,
+            macro_depth: 0,
             module_id,
             file_id: file_id.into(),
             raw_items: &raw_items,
@@ -516,7 +518,7 @@ where
         macros.retain(|directive| {
             if let Some(call_id) = directive.legacy {
                 res = ReachedFixedPoint::No;
-                resolved.push((directive.module_id, call_id));
+                resolved.push((directive.module_id, call_id, directive.depth));
                 return false;
             }
 
@@ -530,7 +532,7 @@ where
                 );
                 resolved_res.resolved_def.take_macros()
             }) {
-                resolved.push((directive.module_id, call_id));
+                resolved.push((directive.module_id, call_id, directive.depth));
                 res = ReachedFixedPoint::No;
                 return false;
             }
@@ -541,7 +543,7 @@ where
             if let Some(call_id) =
                 directive.ast_id.as_call_id(self.db, |path| self.resolve_attribute_macro(&path))
             {
-                resolved.push((directive.module_id, call_id));
+                resolved.push((directive.module_id, call_id, 0));
                 res = ReachedFixedPoint::No;
                 return false;
             }
@@ -552,8 +554,12 @@ where
         self.unexpanded_macros = macros;
         self.unexpanded_attribute_macros = attribute_macros;
 
-        for (module_id, macro_call_id) in resolved {
-            self.collect_macro_expansion(module_id, macro_call_id);
+        for (module_id, macro_call_id, depth) in resolved {
+            if depth > 1024 {
+                log::debug!("Max macro expansion depth reached");
+                continue;
+            }
+            self.collect_macro_expansion(module_id, macro_call_id, depth);
         }
 
         res
@@ -573,12 +579,18 @@ where
         None
     }
 
-    fn collect_macro_expansion(&mut self, module_id: LocalModuleId, macro_call_id: MacroCallId) {
+    fn collect_macro_expansion(
+        &mut self,
+        module_id: LocalModuleId,
+        macro_call_id: MacroCallId,
+        depth: usize,
+    ) {
         let file_id: HirFileId = macro_call_id.as_file();
         let raw_items = self.db.raw_items(file_id);
         let mod_dir = self.mod_dirs[&module_id].clone();
         ModCollector {
             def_collector: &mut *self,
+            macro_depth: depth,
             file_id,
             module_id,
             raw_items: &raw_items,
@@ -595,6 +607,7 @@ where
 /// Walks a single module, populating defs, imports and macros
 struct ModCollector<'a, D> {
     def_collector: D,
+    macro_depth: usize,
     module_id: LocalModuleId,
     file_id: HirFileId,
     raw_items: &'a raw::RawItems,
@@ -684,6 +697,7 @@ where
 
                 ModCollector {
                     def_collector: &mut *self.def_collector,
+                    macro_depth: self.macro_depth,
                     module_id,
                     file_id: self.file_id,
                     raw_items: self.raw_items,
@@ -713,6 +727,7 @@ where
                         let raw_items = self.def_collector.db.raw_items(file_id.into());
                         ModCollector {
                             def_collector: &mut *self.def_collector,
+                            macro_depth: self.macro_depth,
                             module_id,
                             file_id: file_id.into(),
                             raw_items: &raw_items,
@@ -887,6 +902,7 @@ where
                 module_id: self.module_id,
                 ast_id,
                 legacy: Some(macro_call_id),
+                depth: self.macro_depth + 1,
             });
 
             return;
@@ -902,6 +918,7 @@ where
             module_id: self.module_id,
             ast_id,
             legacy: None,
+            depth: self.macro_depth + 1,
         });
     }
 
@@ -971,13 +988,26 @@ mod tests {
     }
 
     #[test]
-    fn test_macro_expand_will_stop() {
+    fn test_macro_expand_will_stop_1() {
+        do_resolve(
+            r#"
+        macro_rules! foo {
+            ($($ty:ty)*) => { foo!($($ty)*); }
+        }
+        foo!(KABOOM);
+        "#,
+        );
+    }
+
+    #[ignore] // this test does succeed, but takes quite a while :/
+    #[test]
+    fn test_macro_expand_will_stop_2() {
         do_resolve(
             r#"
         macro_rules! foo {
-            ($($ty:ty)*) => { foo!($($ty)*, $($ty)*); }
+            ($($ty:ty)*) => { foo!($($ty)* $($ty)*); }
         }
-foo!(KABOOM);
+        foo!(KABOOM);
         "#,
         );
     }
diff --git a/crates/ra_hir_def/src/nameres/tests.rs b/crates/ra_hir_def/src/nameres/tests.rs
index dda5ed699..3f33a75b9 100644
--- a/crates/ra_hir_def/src/nameres/tests.rs
+++ b/crates/ra_hir_def/src/nameres/tests.rs
@@ -102,6 +102,28 @@ fn crate_def_map_super_super() {
 }
 
 #[test]
+fn crate_def_map_fn_mod_same_name() {
+    let map = def_map(
+        "
+        //- /lib.rs
+        mod m {
+            pub mod z {}
+            pub fn z() {}
+        }
+        ",
+    );
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮m: t
+        ⋮
+        ⋮crate::m
+        ⋮z: t v
+        ⋮
+        ⋮crate::m::z
+    "###)
+}
+
+#[test]
 fn bogus_paths() {
     covers!(bogus_paths);
     let map = def_map(
diff --git a/crates/ra_hir_expand/src/builtin_macro.rs b/crates/ra_hir_expand/src/builtin_macro.rs
index a90007f26..f9d3787f6 100644
--- a/crates/ra_hir_expand/src/builtin_macro.rs
+++ b/crates/ra_hir_expand/src/builtin_macro.rs
@@ -88,6 +88,7 @@ register_builtin! {
     (compile_error, CompileError) => compile_error_expand,
     (file, File) => file_expand,
     (line, Line) => line_expand,
+    (assert, Assert) => assert_expand,
     (stringify, Stringify) => stringify_expand,
     (format_args, FormatArgs) => format_args_expand,
     // format_args_nl only differs in that it adds a newline in the end,
@@ -151,6 +152,45 @@ fn column_expand(
     Ok(expanded)
 }
 
+fn assert_expand(
+    _db: &dyn AstDatabase,
+    _id: LazyMacroId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    // A hacky implementation for goto def and hover
+    // We expand `assert!(cond, arg1, arg2)` to
+    // ```
+    // {(cond, &(arg1), &(arg2));}
+    // ```,
+    // which is wrong but useful.
+
+    let mut args = Vec::new();
+    let mut current = Vec::new();
+    for tt in tt.token_trees.iter().cloned() {
+        match tt {
+            tt::TokenTree::Leaf(tt::Leaf::Punct(p)) if p.char == ',' => {
+                args.push(current);
+                current = Vec::new();
+            }
+            _ => {
+                current.push(tt);
+            }
+        }
+    }
+    if !current.is_empty() {
+        args.push(current);
+    }
+
+    let arg_tts = args.into_iter().flat_map(|arg| {
+        quote! { &(##arg), }
+    }.token_trees).collect::<Vec<_>>();
+
+    let expanded = quote! {
+        { { (##arg_tts); } }
+    };
+    Ok(expanded)
+}
+
 fn file_expand(
     _db: &dyn AstDatabase,
     _id: LazyMacroId,
@@ -494,6 +534,22 @@ mod tests {
     }
 
     #[test]
+    fn test_assert_expand() {
+        let expanded = expand_builtin_macro(
+            r#"
+            #[rustc_builtin_macro]
+            macro_rules! assert {
+                ($cond:expr) => ({ /* compiler built-in */ });
+                ($cond:expr, $($args:tt)*) => ({ /* compiler built-in */ })
+            }
+            assert!(true, "{} {:?}", arg1(a, b, c), arg2);
+            "#,
+        );
+
+        assert_eq!(expanded, "{{(&(true), &(\"{} {:?}\"), &(arg1(a,b,c)), &(arg2),);}}");
+    }
+
+    #[test]
     fn test_compile_error_expand() {
         let expanded = expand_builtin_macro(
             r#"
diff --git a/crates/ra_hir_expand/src/name.rs b/crates/ra_hir_expand/src/name.rs
index 6d201256f..25cc1e9fc 100644
--- a/crates/ra_hir_expand/src/name.rs
+++ b/crates/ra_hir_expand/src/name.rs
@@ -172,6 +172,7 @@ pub mod known {
         column,
         compile_error,
         line,
+        assert,
         stringify,
         concat,
         include,
diff --git a/crates/ra_hir_expand/src/quote.rs b/crates/ra_hir_expand/src/quote.rs
index 57e7eebf9..3fd4233da 100644
--- a/crates/ra_hir_expand/src/quote.rs
+++ b/crates/ra_hir_expand/src/quote.rs
@@ -99,6 +99,7 @@ macro_rules! __quote {
     ( & ) => {$crate::__quote!(@PUNCT '&')};
     ( , ) => {$crate::__quote!(@PUNCT ',')};
     ( : ) => {$crate::__quote!(@PUNCT ':')};
+    ( ; ) => {$crate::__quote!(@PUNCT ';')};
     ( :: ) => {$crate::__quote!(@PUNCT ':', ':')};
     ( . ) => {$crate::__quote!(@PUNCT '.')};
     ( < ) => {$crate::__quote!(@PUNCT '<')};
diff --git a/crates/ra_ide/src/call_info.rs b/crates/ra_ide/src/call_info.rs
index 2b35a3803..39d09a07f 100644
--- a/crates/ra_ide/src/call_info.rs
+++ b/crates/ra_ide/src/call_info.rs
@@ -544,6 +544,20 @@ fn main() {
     }
 
     #[test]
+    fn generic_struct() {
+        let info = call_info(
+            r#"
+struct TS<T>(T);
+fn main() {
+    let s = TS(<|>);
+}"#,
+        );
+
+        assert_eq!(info.label(), "struct TS<T>(T) -> TS");
+        assert_eq!(info.active_parameter, Some(0));
+    }
+
+    #[test]
     #[should_panic]
     fn cant_call_named_structs() {
         let _ = call_info(
diff --git a/crates/ra_ide/src/completion.rs b/crates/ra_ide/src/completion.rs
index 93e53c921..cd0757be5 100644
--- a/crates/ra_ide/src/completion.rs
+++ b/crates/ra_ide/src/completion.rs
@@ -75,9 +75,9 @@ impl Default for CompletionOptions {
 pub(crate) fn completions(
     db: &RootDatabase,
     position: FilePosition,
-    opts: &CompletionOptions,
+    options: &CompletionOptions,
 ) -> Option<Completions> {
-    let ctx = CompletionContext::new(db, position, opts)?;
+    let ctx = CompletionContext::new(db, position, options)?;
 
     let mut acc = Completions::default();
 
diff --git a/crates/ra_ide/src/completion/complete_path.rs b/crates/ra_ide/src/completion/complete_path.rs
index d588ee364..3db17f15f 100644
--- a/crates/ra_ide/src/completion/complete_path.rs
+++ b/crates/ra_ide/src/completion/complete_path.rs
@@ -967,4 +967,74 @@ mod tests {
         ]
         "###);
     }
+
+    #[test]
+    fn function_mod_share_name() {
+        assert_debug_snapshot!(
+        do_reference_completion(
+                r"
+                fn foo() {
+                    self::m::<|>
+                }
+
+                mod m {
+                    pub mod z {}
+                    pub fn z() {}
+                }
+                ",
+        ),
+            @r###"
+        [
+            CompletionItem {
+                label: "z",
+                source_range: [57; 57),
+                delete: [57; 57),
+                insert: "z",
+                kind: Module,
+            },
+            CompletionItem {
+                label: "z()",
+                source_range: [57; 57),
+                delete: [57; 57),
+                insert: "z()$0",
+                kind: Function,
+                lookup: "z",
+                detail: "pub fn z()",
+            },
+        ]
+        "###
+        );
+    }
+
+    #[test]
+    fn completes_hashmap_new() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                r"
+                struct RandomState;
+                struct HashMap<K, V, S = RandomState> {}
+
+                impl<K, V> HashMap<K, V, RandomState> {
+                    pub fn new() -> HashMap<K, V, RandomState> { }
+                }
+                fn foo() {
+                    HashMap::<|>
+                }
+                "
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "new()",
+                source_range: [292; 292),
+                delete: [292; 292),
+                insert: "new()$0",
+                kind: Function,
+                lookup: "new",
+                detail: "pub fn new() -> HashMap<K, V, RandomState>",
+            },
+        ]
+        "###
+        );
+    }
 }
diff --git a/crates/ra_ide/src/completion/complete_scope.rs b/crates/ra_ide/src/completion/complete_scope.rs
index bd4adf23a..5ffff5a1c 100644
--- a/crates/ra_ide/src/completion/complete_scope.rs
+++ b/crates/ra_ide/src/completion/complete_scope.rs
@@ -42,6 +42,7 @@ mod tests {
                 kind: Function,
                 lookup: "quux",
                 detail: "fn quux(x: i32)",
+                trigger_call_info: true,
             },
             CompletionItem {
                 label: "x",
@@ -844,6 +845,7 @@ mod tests {
                 kind: Function,
                 lookup: "quux",
                 detail: "fn quux(x: i32)",
+                trigger_call_info: true,
             },
             CompletionItem {
                 label: "x",
@@ -865,4 +867,38 @@ mod tests {
         "###
         );
     }
+
+    #[test]
+    fn completes_unresolved_uses() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                r"
+                use spam::Quux;
+
+                fn main() {
+                    <|>
+                }
+                "
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "Quux",
+                source_range: [82; 82),
+                delete: [82; 82),
+                insert: "Quux",
+            },
+            CompletionItem {
+                label: "main()",
+                source_range: [82; 82),
+                delete: [82; 82),
+                insert: "main()$0",
+                kind: Function,
+                lookup: "main",
+                detail: "fn main()",
+            },
+        ]
+        "###
+        );
+    }
 }
diff --git a/crates/ra_ide/src/completion/completion_item.rs b/crates/ra_ide/src/completion/completion_item.rs
index ef0eb43b2..bc0f1aff5 100644
--- a/crates/ra_ide/src/completion/completion_item.rs
+++ b/crates/ra_ide/src/completion/completion_item.rs
@@ -80,6 +80,9 @@ impl fmt::Debug for CompletionItem {
         if self.deprecated {
             s.field("deprecated", &true);
         }
+        if self.trigger_call_info {
+            s.field("trigger_call_info", &true);
+        }
         s.finish()
     }
 }
diff --git a/crates/ra_ide/src/completion/presentation.rs b/crates/ra_ide/src/completion/presentation.rs
index 5213def20..910844244 100644
--- a/crates/ra_ide/src/completion/presentation.rs
+++ b/crates/ra_ide/src/completion/presentation.rs
@@ -273,8 +273,10 @@ impl Completions {
     pub(crate) fn add_enum_variant(&mut self, ctx: &CompletionContext, variant: hir::EnumVariant) {
         let is_deprecated = is_deprecated(variant, ctx.db);
         let name = variant.name(ctx.db);
-        let detail_types =
-            variant.fields(ctx.db).into_iter().map(|field| (field.name(ctx.db), field.ty(ctx.db)));
+        let detail_types = variant
+            .fields(ctx.db)
+            .into_iter()
+            .map(|field| (field.name(ctx.db), field.signature_ty(ctx.db)));
         let detail = match variant.kind(ctx.db) {
             StructKind::Tuple | StructKind::Unit => {
                 join(detail_types.map(|(_, t)| t.display(ctx.db).to_string()))
@@ -510,6 +512,7 @@ mod tests {
                 kind: Function,
                 lookup: "with_args",
                 detail: "fn with_args(x: i32, y: String)",
+                trigger_call_info: true,
             },
         ]
         "###
@@ -566,6 +569,7 @@ mod tests {
                 kind: Method,
                 lookup: "foo",
                 detail: "fn foo(&self, x: i32)",
+                trigger_call_info: true,
             },
         ]
         "###
@@ -600,6 +604,7 @@ mod tests {
                 kind: Method,
                 lookup: "foo",
                 detail: "fn foo(&self, x: i32)",
+                trigger_call_info: true,
             },
         ]
         "###
@@ -718,6 +723,7 @@ mod tests {
                 kind: Function,
                 lookup: "foo",
                 detail: "fn foo(xs: Ve)",
+                trigger_call_info: true,
             },
         ]
         "###
@@ -747,6 +753,7 @@ mod tests {
                 kind: Function,
                 lookup: "foo",
                 detail: "fn foo(xs: Ve)",
+                trigger_call_info: true,
             },
         ]
         "###
@@ -775,6 +782,7 @@ mod tests {
                 kind: Function,
                 lookup: "foo",
                 detail: "fn foo(xs: Ve)",
+                trigger_call_info: true,
             },
         ]
         "###
@@ -803,6 +811,7 @@ mod tests {
                 kind: Function,
                 lookup: "foo",
                 detail: "fn foo(xs: Ve<i128>)",
+                trigger_call_info: true,
             },
         ]
         "###
diff --git a/crates/ra_ide/src/display/function_signature.rs b/crates/ra_ide/src/display/function_signature.rs
index 2c4c932de..ec1bbd5a0 100644
--- a/crates/ra_ide/src/display/function_signature.rs
+++ b/crates/ra_ide/src/display/function_signature.rs
@@ -64,7 +64,7 @@ impl FunctionSignature {
             .fields(db)
             .into_iter()
             .map(|field: hir::StructField| {
-                let ty = field.ty(db);
+                let ty = field.signature_ty(db);
                 format!("{}", ty.display(db))
             })
             .collect();
@@ -102,7 +102,7 @@ impl FunctionSignature {
             .into_iter()
             .map(|field: hir::StructField| {
                 let name = field.name(db);
-                let ty = field.ty(db);
+                let ty = field.signature_ty(db);
                 format!("{}: {}", name, ty.display(db))
             })
             .collect();
diff --git a/crates/ra_ide/src/hover.rs b/crates/ra_ide/src/hover.rs
index 25e038a55..0bbba4855 100644
--- a/crates/ra_ide/src/hover.rs
+++ b/crates/ra_ide/src/hover.rs
@@ -833,19 +833,34 @@ fn func(foo: i32) { if true { <|>foo; }; }
     }
 
     #[test]
+    fn test_hover_through_assert_macro() {
+        let hover_on = check_hover_result(
+            r#"
+            //- /lib.rs
+            #[rustc_builtin_macro]
+            macro_rules! assert {}
+
+            fn bar() -> bool { true }
+            fn foo() {
+                assert!(ba<|>r());
+            }
+            "#,
+            &["fn bar() -> bool"],
+        );
+
+        assert_eq!(hover_on, "bar");
+    }
+
+    #[test]
     fn test_hover_through_literal_string_in_builtin_macro() {
         check_hover_no_result(
             r#"
             //- /lib.rs
             #[rustc_builtin_macro]
-            macro_rules! assert {
-                ($cond:expr) => {{ /* compiler built-in */ }};
-                ($cond:expr,) => {{ /* compiler built-in */ }};
-                ($cond:expr, $($arg:tt)+) => {{ /* compiler built-in */ }};
-            }
+            macro_rules! format {}
 
             fn foo() {
-                assert!("hel<|>lo");
+                format!("hel<|>lo {}", 0);
             }
             "#,
         );
diff --git a/crates/ra_ide/src/inlay_hints.rs b/crates/ra_ide/src/inlay_hints.rs
index cf0cbdbd0..ecd615cf4 100644
--- a/crates/ra_ide/src/inlay_hints.rs
+++ b/crates/ra_ide/src/inlay_hints.rs
@@ -10,7 +10,20 @@ use ra_syntax::{
 
 use crate::{FileId, FunctionSignature};
 
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct InlayHintsOptions {
+    pub type_hints: bool,
+    pub parameter_hints: bool,
+    pub max_length: Option<usize>,
+}
+
+impl Default for InlayHintsOptions {
+    fn default() -> Self {
+        Self { type_hints: true, parameter_hints: true, max_length: None }
+    }
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub enum InlayKind {
     TypeHint,
     ParameterHint,
@@ -26,7 +39,7 @@ pub struct InlayHint {
 pub(crate) fn inlay_hints(
     db: &RootDatabase,
     file_id: FileId,
-    max_inlay_hint_length: Option<usize>,
+    options: &InlayHintsOptions,
 ) -> Vec<InlayHint> {
     let _p = profile("inlay_hints");
     let sema = Semantics::new(db);
@@ -36,9 +49,9 @@ pub(crate) fn inlay_hints(
     for node in file.syntax().descendants() {
         match_ast! {
             match node {
-                ast::CallExpr(it) => { get_param_name_hints(&mut res, &sema, ast::Expr::from(it)); },
-                ast::MethodCallExpr(it) => { get_param_name_hints(&mut res, &sema, ast::Expr::from(it)); },
-                ast::BindPat(it) => { get_bind_pat_hints(&mut res, &sema, max_inlay_hint_length, it); },
+                ast::CallExpr(it) => { get_param_name_hints(&mut res, &sema, options, ast::Expr::from(it)); },
+                ast::MethodCallExpr(it) => { get_param_name_hints(&mut res, &sema, options, ast::Expr::from(it)); },
+                ast::BindPat(it) => { get_bind_pat_hints(&mut res, &sema, options, it); },
                 _ => (),
             }
         }
@@ -49,8 +62,13 @@ pub(crate) fn inlay_hints(
 fn get_param_name_hints(
     acc: &mut Vec<InlayHint>,
     sema: &Semantics<RootDatabase>,
+    options: &InlayHintsOptions,
     expr: ast::Expr,
 ) -> Option<()> {
+    if !options.parameter_hints {
+        return None;
+    }
+
     let args = match &expr {
         ast::Expr::CallExpr(expr) => expr.arg_list()?.args(),
         ast::Expr::MethodCallExpr(expr) => expr.arg_list()?.args(),
@@ -84,9 +102,13 @@ fn get_param_name_hints(
 fn get_bind_pat_hints(
     acc: &mut Vec<InlayHint>,
     sema: &Semantics<RootDatabase>,
-    max_inlay_hint_length: Option<usize>,
+    options: &InlayHintsOptions,
     pat: ast::BindPat,
 ) -> Option<()> {
+    if !options.type_hints {
+        return None;
+    }
+
     let ty = sema.type_of_pat(&pat.clone().into())?;
 
     if should_not_display_type_hint(sema.db, &pat, &ty) {
@@ -96,7 +118,7 @@ fn get_bind_pat_hints(
     acc.push(InlayHint {
         range: pat.syntax().text_range(),
         kind: InlayKind::TypeHint,
-        label: ty.display_truncated(sema.db, max_inlay_hint_length).to_string().into(),
+        label: ty.display_truncated(sema.db, options.max_length).to_string().into(),
     });
     Some(())
 }
@@ -202,11 +224,66 @@ fn get_fn_signature(sema: &Semantics<RootDatabase>, expr: &ast::Expr) -> Option<
 
 #[cfg(test)]
 mod tests {
+    use crate::inlay_hints::InlayHintsOptions;
     use insta::assert_debug_snapshot;
 
     use crate::mock_analysis::single_file;
 
     #[test]
+    fn param_hints_only() {
+        let (analysis, file_id) = single_file(
+            r#"
+            fn foo(a: i32, b: i32) -> i32 { a + b }
+            fn main() {
+                let _x = foo(4, 4);
+            }"#,
+        );
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions{ parameter_hints: true, type_hints: false, max_length: None}).unwrap(), @r###"
+        [
+            InlayHint {
+                range: [106; 107),
+                kind: ParameterHint,
+                label: "a",
+            },
+            InlayHint {
+                range: [109; 110),
+                kind: ParameterHint,
+                label: "b",
+            },
+        ]"###);
+    }
+
+    #[test]
+    fn hints_disabled() {
+        let (analysis, file_id) = single_file(
+            r#"
+            fn foo(a: i32, b: i32) -> i32 { a + b }
+            fn main() {
+                let _x = foo(4, 4);
+            }"#,
+        );
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions{ type_hints: false, parameter_hints: false, max_length: None}).unwrap(), @r###"[]"###);
+    }
+
+    #[test]
+    fn type_hints_only() {
+        let (analysis, file_id) = single_file(
+            r#"
+            fn foo(a: i32, b: i32) -> i32 { a + b }
+            fn main() {
+                let _x = foo(4, 4);
+            }"#,
+        );
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions{ type_hints: true, parameter_hints: false, max_length: None}).unwrap(), @r###"
+        [
+            InlayHint {
+                range: [97; 99),
+                kind: TypeHint,
+                label: "i32",
+            },
+        ]"###);
+    }
+    #[test]
     fn default_generic_types_should_not_be_displayed() {
         let (analysis, file_id) = single_file(
             r#"
@@ -221,7 +298,7 @@ fn main() {
 }"#,
         );
 
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, None).unwrap(), @r###"
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions::default()).unwrap(), @r###"
         [
             InlayHint {
                 range: [69; 71),
@@ -278,7 +355,7 @@ fn main() {
 }"#,
         );
 
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, None).unwrap(), @r###"
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions::default()).unwrap(), @r###"
         [
             InlayHint {
                 range: [193; 197),
@@ -358,7 +435,7 @@ fn main() {
 }"#,
         );
 
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, None).unwrap(), @r###"
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions::default()).unwrap(), @r###"
         [
             InlayHint {
                 range: [21; 30),
@@ -422,7 +499,7 @@ fn main() {
 }"#,
         );
 
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, None).unwrap(), @r###"
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions::default()).unwrap(), @r###"
         [
             InlayHint {
                 range: [21; 30),
@@ -472,7 +549,7 @@ fn main() {
 }"#,
         );
 
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, None).unwrap(), @r###"
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions::default()).unwrap(), @r###"
         [
             InlayHint {
                 range: [188; 192),
@@ -567,7 +644,7 @@ fn main() {
 }"#,
         );
 
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, None).unwrap(), @r###"
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions::default()).unwrap(), @r###"
         [
             InlayHint {
                 range: [188; 192),
@@ -662,7 +739,7 @@ fn main() {
 }"#,
         );
 
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, None).unwrap(), @r###"
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions::default()).unwrap(), @r###"
         [
             InlayHint {
                 range: [252; 256),
@@ -734,7 +811,7 @@ fn main() {
 }"#,
         );
 
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, Some(8)).unwrap(), @r###"
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions { max_length: Some(8), ..Default::default() }).unwrap(), @r###"
         [
             InlayHint {
                 range: [74; 75),
@@ -822,7 +899,7 @@ fn main() {
 }"#,
         );
 
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, None).unwrap(), @r###"
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions::default()).unwrap(), @r###"
         [
             InlayHint {
                 range: [798; 809),
@@ -944,7 +1021,7 @@ fn main() {
 }"#,
         );
 
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, Some(8)).unwrap(), @r###"
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions { max_length: Some(8), ..Default::default() }).unwrap(), @r###"
         []
         "###
         );
@@ -970,7 +1047,7 @@ fn main() {
 }"#,
         );
 
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, Some(8)).unwrap(), @r###"
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsOptions { max_length: Some(8), ..Default::default() }).unwrap(), @r###"
         []
         "###
         );
diff --git a/crates/ra_ide/src/lib.rs b/crates/ra_ide/src/lib.rs
index 015fae195..e9af80b6c 100644
--- a/crates/ra_ide/src/lib.rs
+++ b/crates/ra_ide/src/lib.rs
@@ -68,7 +68,7 @@ pub use crate::{
     expand_macro::ExpandedMacro,
     folding_ranges::{Fold, FoldKind},
     hover::HoverResult,
-    inlay_hints::{InlayHint, InlayKind},
+    inlay_hints::{InlayHint, InlayHintsOptions, InlayKind},
     references::{Declaration, Reference, ReferenceAccess, ReferenceKind, ReferenceSearchResult},
     runnables::{Runnable, RunnableKind, TestId},
     source_change::{FileSystemEdit, SourceChange, SourceFileEdit},
@@ -319,9 +319,9 @@ impl Analysis {
     pub fn inlay_hints(
         &self,
         file_id: FileId,
-        max_inlay_hint_length: Option<usize>,
+        inlay_hint_opts: &InlayHintsOptions,
     ) -> Cancelable<Vec<InlayHint>> {
-        self.with_db(|db| inlay_hints::inlay_hints(db, file_id, max_inlay_hint_length))
+        self.with_db(|db| inlay_hints::inlay_hints(db, file_id, inlay_hint_opts))
     }
 
     /// Returns the set of folding ranges.
diff --git a/crates/ra_ide/src/syntax_tree.rs b/crates/ra_ide/src/syntax_tree.rs
index 55966daf3..f58e436d1 100644
--- a/crates/ra_ide/src/syntax_tree.rs
+++ b/crates/ra_ide/src/syntax_tree.rs
@@ -5,7 +5,7 @@ use ra_ide_db::RootDatabase;
 use ra_syntax::{
     algo, AstNode, NodeOrToken, SourceFile,
     SyntaxKind::{RAW_STRING, STRING},
-    SyntaxToken, TextRange,
+    SyntaxToken, TextRange, TextUnit,
 };
 
 pub use ra_db::FileId;
@@ -56,19 +56,23 @@ fn syntax_tree_for_token(node: &SyntaxToken, text_range: TextRange) -> Option<St
     let start = text_range.start() - node_range.start();
 
     // how many characters we have selected
-    let len = text_range.len().to_usize();
+    let len = text_range.len();
 
-    let node_len = node_range.len().to_usize();
+    let node_len = node_range.len();
 
-    let start = start.to_usize();
+    let start = start;
 
     // We want to cap our length
     let len = len.min(node_len);
 
     // Ensure our slice is inside the actual string
-    let end = if start + len < text.len() { start + len } else { text.len() - start };
+    let end = if start + len < TextUnit::of_str(&text) {
+        start + len
+    } else {
+        TextUnit::of_str(&text) - start
+    };
 
-    let text = &text[start..end];
+    let text = &text[TextRange::from_to(start, end)];
 
     // Remove possible extra string quotes from the start
     // and the end of the string
diff --git a/crates/ra_ide_db/src/line_index.rs b/crates/ra_ide_db/src/line_index.rs
index b9db5c276..8ae745ff2 100644
--- a/crates/ra_ide_db/src/line_index.rs
+++ b/crates/ra_ide_db/src/line_index.rs
@@ -59,7 +59,7 @@ impl LineIndex {
             }
 
             let char_len = TextUnit::of_char(c);
-            if char_len.to_usize() > 1 {
+            if char_len > TextUnit::from_usize(1) {
                 utf16_chars.push(Utf16Char { start: curr_col, end: curr_col + char_len });
             }
 
@@ -101,12 +101,12 @@ impl LineIndex {
             .filter(|it| !it.is_empty())
     }
 
-    fn utf8_to_utf16_col(&self, line: u32, mut col: TextUnit) -> usize {
+    fn utf8_to_utf16_col(&self, line: u32, col: TextUnit) -> usize {
         if let Some(utf16_chars) = self.utf16_lines.get(&line) {
-            let mut correction = TextUnit::from_usize(0);
+            let mut correction = 0;
             for c in utf16_chars {
                 if col >= c.end {
-                    correction += c.len() - TextUnit::from_usize(1);
+                    correction += c.len().to_usize() - 1;
                 } else {
                     // From here on, all utf16 characters come *after* the character we are mapping,
                     // so we don't need to take them into account
@@ -114,10 +114,10 @@ impl LineIndex {
                 }
             }
 
-            col -= correction;
+            col.to_usize() - correction
+        } else {
+            col.to_usize()
         }
-
-        col.to_usize()
     }
 
     fn utf16_to_utf8_col(&self, line: u32, col: u32) -> TextUnit {
diff --git a/crates/ra_ide_db/src/line_index_utils.rs b/crates/ra_ide_db/src/line_index_utils.rs
index 75a498151..2ebbabdc6 100644
--- a/crates/ra_ide_db/src/line_index_utils.rs
+++ b/crates/ra_ide_db/src/line_index_utils.rs
@@ -145,7 +145,7 @@ impl Iterator for OffsetStepIter<'_> {
                     Some((next, next_offset))
                 } else {
                     let char_len = TextUnit::of_char(c);
-                    if char_len.to_usize() > 1 {
+                    if char_len > TextUnit::from_usize(1) {
                         let start = self.offset + TextUnit::from_usize(i);
                         let end = start + char_len;
                         let next = Step::Utf16Char(TextRange::from_to(start, end));
diff --git a/crates/ra_parser/src/grammar/params.rs b/crates/ra_parser/src/grammar/params.rs
index 272661b1d..f0da173cc 100644
--- a/crates/ra_parser/src/grammar/params.rs
+++ b/crates/ra_parser/src/grammar/params.rs
@@ -56,21 +56,17 @@ fn list_(p: &mut Parser, flavor: Flavor) {
         // fn f(#[attr1] pat: Type) {}
         attributes::outer_attributes(p);
 
-        // test param_list_vararg
-        // extern "C" { fn printf(format: *const i8, ...) -> i32; }
-        match flavor {
-            FnDef | FnPointer if p.eat(T![...]) => break,
-            _ => (),
-        }
-
         if !p.at_ts(VALUE_PARAMETER_FIRST) {
             p.error("expected value parameter");
             break;
         }
-        value_parameter(p, flavor);
+        let param = value_parameter(p, flavor);
         if !p.at(ket) {
             p.expect(T![,]);
         }
+        if let Variadic(true) = param {
+            break;
+        }
     }
 
     p.expect(ket);
@@ -79,32 +75,25 @@ fn list_(p: &mut Parser, flavor: Flavor) {
 
 const VALUE_PARAMETER_FIRST: TokenSet = patterns::PATTERN_FIRST.union(types::TYPE_FIRST);
 
-fn value_parameter(p: &mut Parser, flavor: Flavor) {
+struct Variadic(bool);
+
+fn value_parameter(p: &mut Parser, flavor: Flavor) -> Variadic {
+    let mut res = Variadic(false);
     let m = p.start();
     match flavor {
-        // test trait_fn_placeholder_parameter
-        // trait Foo {
-        //     fn bar(_: u64, mut x: i32);
-        // }
-
-        // test trait_fn_patterns
-        // trait T {
-        //     fn f1((a, b): (usize, usize)) {}
-        //     fn f2(S { a, b }: S) {}
-        //     fn f3(NewType(a): NewType) {}
-        //     fn f4(&&a: &&usize) {}
-        // }
+        // test param_list_vararg
+        // extern "C" { fn printf(format: *const i8, ...) -> i32; }
+        Flavor::FnDef | Flavor::FnPointer if p.eat(T![...]) => res = Variadic(true),
 
-        // test fn_patterns
-        // impl U {
-        //     fn f1((a, b): (usize, usize)) {}
-        //     fn f2(S { a, b }: S) {}
-        //     fn f3(NewType(a): NewType) {}
-        //     fn f4(&&a: &&usize) {}
-        // }
+        // test fn_def_param
+        // fn foo((x, y): (i32, i32)) {}
         Flavor::FnDef => {
             patterns::pattern(p);
-            types::ascription(p);
+            if variadic_param(p) {
+                res = Variadic(true)
+            } else {
+                types::ascription(p);
+            }
         }
         // test value_parameters_no_patterns
         // type F = Box<Fn(i32, &i32, &i32, ())>;
@@ -120,7 +109,11 @@ fn value_parameter(p: &mut Parser, flavor: Flavor) {
         Flavor::FnPointer => {
             if (p.at(IDENT) || p.at(UNDERSCORE)) && p.nth(1) == T![:] && !p.nth_at(1, T![::]) {
                 patterns::pattern_single(p);
-                types::ascription(p);
+                if variadic_param(p) {
+                    res = Variadic(true)
+                } else {
+                    types::ascription(p);
+                }
             } else {
                 types::type_(p);
             }
@@ -137,6 +130,17 @@ fn value_parameter(p: &mut Parser, flavor: Flavor) {
         }
     }
     m.complete(p, PARAM);
+    res
+}
+
+fn variadic_param(p: &mut Parser) -> bool {
+    if p.at(T![:]) && p.nth_at(1, T![...]) {
+        p.bump(T![:]);
+        p.bump(T![...]);
+        true
+    } else {
+        false
+    }
 }
 
 // test self_param
diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index 4a70c712f..26fafb469 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -30,7 +30,7 @@ pub use self::{
 /// conversion itself has zero runtime cost: ast and syntax nodes have exactly
 /// the same representation: a pointer to the tree root and a pointer to the
 /// node itself.
-pub trait AstNode {
+pub trait AstNode: std::fmt::Display {
     fn can_cast(kind: SyntaxKind) -> bool
     where
         Self: Sized;
diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index 150893e39..002f453cd 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -9,6 +9,11 @@ use crate::{
 pub struct SourceFile {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for SourceFile {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for SourceFile {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -38,6 +43,11 @@ impl SourceFile {
 pub struct FnDef {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for FnDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for FnDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -76,6 +86,11 @@ impl FnDef {
 pub struct RetType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RetType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RetType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -103,6 +118,11 @@ impl RetType {
 pub struct StructDef {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for StructDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for StructDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -131,6 +151,11 @@ impl StructDef {}
 pub struct UnionDef {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for UnionDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for UnionDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -163,6 +188,11 @@ impl UnionDef {
 pub struct RecordFieldDefList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RecordFieldDefList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RecordFieldDefList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -190,6 +220,11 @@ impl RecordFieldDefList {
 pub struct RecordFieldDef {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RecordFieldDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RecordFieldDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -218,6 +253,11 @@ impl RecordFieldDef {}
 pub struct TupleFieldDefList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TupleFieldDefList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TupleFieldDefList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -245,6 +285,11 @@ impl TupleFieldDefList {
 pub struct TupleFieldDef {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TupleFieldDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TupleFieldDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -274,6 +319,11 @@ impl TupleFieldDef {
 pub struct EnumDef {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for EnumDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for EnumDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -306,6 +356,11 @@ impl EnumDef {
 pub struct EnumVariantList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for EnumVariantList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for EnumVariantList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -333,6 +388,11 @@ impl EnumVariantList {
 pub struct EnumVariant {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for EnumVariant {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for EnumVariant {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -363,6 +423,11 @@ impl EnumVariant {
 pub struct TraitDef {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TraitDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TraitDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -396,6 +461,11 @@ impl TraitDef {
 pub struct Module {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for Module {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Module {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -427,6 +497,11 @@ impl Module {
 pub struct ItemList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ItemList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ItemList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -456,6 +531,11 @@ impl ItemList {
 pub struct ConstDef {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ConstDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ConstDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -489,6 +569,11 @@ impl ConstDef {
 pub struct StaticDef {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for StaticDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for StaticDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -522,6 +607,11 @@ impl StaticDef {
 pub struct TypeAliasDef {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TypeAliasDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TypeAliasDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -555,6 +645,11 @@ impl TypeAliasDef {
 pub struct ImplDef {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ImplDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ImplDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -584,6 +679,11 @@ impl ImplDef {
 pub struct ParenType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ParenType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ParenType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -611,6 +711,11 @@ impl ParenType {
 pub struct TupleType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TupleType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TupleType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -638,6 +743,11 @@ impl TupleType {
 pub struct NeverType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for NeverType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for NeverType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -661,6 +771,11 @@ impl NeverType {}
 pub struct PathType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for PathType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for PathType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -688,6 +803,11 @@ impl PathType {
 pub struct PointerType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for PointerType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for PointerType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -715,6 +835,11 @@ impl PointerType {
 pub struct ArrayType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ArrayType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ArrayType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -745,6 +870,11 @@ impl ArrayType {
 pub struct SliceType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for SliceType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for SliceType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -772,6 +902,11 @@ impl SliceType {
 pub struct ReferenceType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ReferenceType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ReferenceType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -799,6 +934,11 @@ impl ReferenceType {
 pub struct PlaceholderType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for PlaceholderType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for PlaceholderType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -822,6 +962,11 @@ impl PlaceholderType {}
 pub struct FnPointerType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for FnPointerType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for FnPointerType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -852,6 +997,11 @@ impl FnPointerType {
 pub struct ForType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ForType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ForType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -879,6 +1029,11 @@ impl ForType {
 pub struct ImplTraitType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ImplTraitType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ImplTraitType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -903,6 +1058,11 @@ impl ImplTraitType {}
 pub struct DynTraitType {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for DynTraitType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for DynTraitType {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -927,6 +1087,11 @@ impl DynTraitType {}
 pub struct TupleExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TupleExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TupleExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -954,6 +1119,11 @@ impl TupleExpr {
 pub struct ArrayExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ArrayExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ArrayExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -981,6 +1151,11 @@ impl ArrayExpr {
 pub struct ParenExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ParenExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ParenExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1008,6 +1183,11 @@ impl ParenExpr {
 pub struct PathExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for PathExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for PathExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1035,6 +1215,11 @@ impl PathExpr {
 pub struct LambdaExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for LambdaExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for LambdaExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1068,6 +1253,11 @@ impl LambdaExpr {
 pub struct IfExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for IfExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for IfExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1095,6 +1285,11 @@ impl IfExpr {
 pub struct LoopExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for LoopExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for LoopExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1119,6 +1314,11 @@ impl LoopExpr {}
 pub struct TryBlockExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TryBlockExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TryBlockExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1146,6 +1346,11 @@ impl TryBlockExpr {
 pub struct ForExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ForExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ForExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1177,6 +1382,11 @@ impl ForExpr {
 pub struct WhileExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for WhileExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for WhileExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1205,6 +1415,11 @@ impl WhileExpr {
 pub struct ContinueExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ContinueExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ContinueExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1228,6 +1443,11 @@ impl ContinueExpr {}
 pub struct BreakExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for BreakExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for BreakExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1255,6 +1475,11 @@ impl BreakExpr {
 pub struct Label {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for Label {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Label {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1278,6 +1503,11 @@ impl Label {}
 pub struct BlockExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for BlockExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for BlockExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1305,6 +1535,11 @@ impl BlockExpr {
 pub struct ReturnExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ReturnExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ReturnExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1332,6 +1567,11 @@ impl ReturnExpr {
 pub struct CallExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for CallExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for CallExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1360,6 +1600,11 @@ impl CallExpr {
 pub struct MethodCallExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for MethodCallExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for MethodCallExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1394,6 +1639,11 @@ impl MethodCallExpr {
 pub struct IndexExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for IndexExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for IndexExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1417,6 +1667,11 @@ impl IndexExpr {}
 pub struct FieldExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for FieldExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for FieldExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1447,6 +1702,11 @@ impl FieldExpr {
 pub struct AwaitExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for AwaitExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for AwaitExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1474,6 +1734,11 @@ impl AwaitExpr {
 pub struct TryExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TryExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TryExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1501,6 +1766,11 @@ impl TryExpr {
 pub struct CastExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for CastExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for CastExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1531,6 +1801,11 @@ impl CastExpr {
 pub struct RefExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RefExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RefExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1558,6 +1833,11 @@ impl RefExpr {
 pub struct PrefixExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for PrefixExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for PrefixExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1585,6 +1865,11 @@ impl PrefixExpr {
 pub struct BoxExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for BoxExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for BoxExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1612,6 +1897,11 @@ impl BoxExpr {
 pub struct RangeExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RangeExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RangeExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1635,6 +1925,11 @@ impl RangeExpr {}
 pub struct BinExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for BinExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for BinExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1658,6 +1953,11 @@ impl BinExpr {}
 pub struct Literal {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for Literal {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Literal {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1681,6 +1981,11 @@ impl Literal {}
 pub struct MatchExpr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for MatchExpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for MatchExpr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1711,6 +2016,11 @@ impl MatchExpr {
 pub struct MatchArmList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for MatchArmList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for MatchArmList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1739,6 +2049,11 @@ impl MatchArmList {
 pub struct MatchArm {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for MatchArm {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for MatchArm {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1773,6 +2088,11 @@ impl MatchArm {
 pub struct MatchGuard {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for MatchGuard {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for MatchGuard {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1800,6 +2120,11 @@ impl MatchGuard {
 pub struct RecordLit {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RecordLit {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RecordLit {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1830,6 +2155,11 @@ impl RecordLit {
 pub struct RecordFieldList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RecordFieldList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RecordFieldList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1860,6 +2190,11 @@ impl RecordFieldList {
 pub struct RecordField {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RecordField {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RecordField {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1890,6 +2225,11 @@ impl RecordField {
 pub struct OrPat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for OrPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for OrPat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1917,6 +2257,11 @@ impl OrPat {
 pub struct ParenPat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ParenPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ParenPat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1944,6 +2289,11 @@ impl ParenPat {
 pub struct RefPat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RefPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RefPat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1971,6 +2321,11 @@ impl RefPat {
 pub struct BoxPat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for BoxPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for BoxPat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -1998,6 +2353,11 @@ impl BoxPat {
 pub struct BindPat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for BindPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for BindPat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2026,6 +2386,11 @@ impl BindPat {
 pub struct PlaceholderPat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for PlaceholderPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for PlaceholderPat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2049,6 +2414,11 @@ impl PlaceholderPat {}
 pub struct DotDotPat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for DotDotPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for DotDotPat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2072,6 +2442,11 @@ impl DotDotPat {}
 pub struct PathPat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for PathPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for PathPat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2099,6 +2474,11 @@ impl PathPat {
 pub struct SlicePat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for SlicePat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for SlicePat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2126,6 +2506,11 @@ impl SlicePat {
 pub struct RangePat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RangePat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RangePat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2149,6 +2534,11 @@ impl RangePat {}
 pub struct LiteralPat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for LiteralPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for LiteralPat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2176,6 +2566,11 @@ impl LiteralPat {
 pub struct RecordPat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RecordPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RecordPat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2206,6 +2601,11 @@ impl RecordPat {
 pub struct RecordFieldPatList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RecordFieldPatList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RecordFieldPatList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2236,6 +2636,11 @@ impl RecordFieldPatList {
 pub struct RecordFieldPat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for RecordFieldPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for RecordFieldPat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2264,6 +2669,11 @@ impl RecordFieldPat {
 pub struct TupleStructPat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TupleStructPat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TupleStructPat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2294,6 +2704,11 @@ impl TupleStructPat {
 pub struct TuplePat {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TuplePat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TuplePat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2321,6 +2736,11 @@ impl TuplePat {
 pub struct Visibility {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for Visibility {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Visibility {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2344,6 +2764,11 @@ impl Visibility {}
 pub struct Name {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for Name {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Name {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2367,6 +2792,11 @@ impl Name {}
 pub struct NameRef {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for NameRef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for NameRef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2390,6 +2820,11 @@ impl NameRef {}
 pub struct MacroCall {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for MacroCall {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for MacroCall {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2423,6 +2858,11 @@ impl MacroCall {
 pub struct Attr {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for Attr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Attr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2453,6 +2893,11 @@ impl Attr {
 pub struct TokenTree {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TokenTree {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TokenTree {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2476,6 +2921,11 @@ impl TokenTree {}
 pub struct TypeParamList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TypeParamList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TypeParamList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2506,6 +2956,11 @@ impl TypeParamList {
 pub struct TypeParam {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TypeParam {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TypeParam {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2536,6 +2991,11 @@ impl TypeParam {
 pub struct ConstParam {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ConstParam {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ConstParam {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2566,6 +3026,11 @@ impl ConstParam {
 pub struct LifetimeParam {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for LifetimeParam {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for LifetimeParam {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2590,6 +3055,11 @@ impl LifetimeParam {}
 pub struct TypeBound {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TypeBound {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TypeBound {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2617,6 +3087,11 @@ impl TypeBound {
 pub struct TypeBoundList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TypeBoundList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TypeBoundList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2644,6 +3119,11 @@ impl TypeBoundList {
 pub struct WherePred {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for WherePred {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for WherePred {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2672,6 +3152,11 @@ impl WherePred {
 pub struct WhereClause {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for WhereClause {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for WhereClause {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2699,6 +3184,11 @@ impl WhereClause {
 pub struct ExprStmt {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ExprStmt {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ExprStmt {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2726,6 +3216,11 @@ impl ExprStmt {
 pub struct LetStmt {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for LetStmt {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for LetStmt {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2757,6 +3252,11 @@ impl LetStmt {
 pub struct Condition {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for Condition {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Condition {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2787,6 +3287,11 @@ impl Condition {
 pub struct Block {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for Block {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Block {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2819,6 +3324,11 @@ impl Block {
 pub struct ParamList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ParamList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ParamList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2849,6 +3359,11 @@ impl ParamList {
 pub struct SelfParam {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for SelfParam {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for SelfParam {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2874,6 +3389,11 @@ impl SelfParam {}
 pub struct Param {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for Param {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Param {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2903,6 +3423,11 @@ impl Param {
 pub struct UseItem {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for UseItem {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for UseItem {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2932,6 +3457,11 @@ impl UseItem {
 pub struct UseTree {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for UseTree {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for UseTree {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2965,6 +3495,11 @@ impl UseTree {
 pub struct Alias {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for Alias {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Alias {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -2989,6 +3524,11 @@ impl Alias {}
 pub struct UseTreeList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for UseTreeList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for UseTreeList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3016,6 +3556,11 @@ impl UseTreeList {
 pub struct ExternCrateItem {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ExternCrateItem {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ExternCrateItem {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3048,6 +3593,11 @@ impl ExternCrateItem {
 pub struct ArgList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ArgList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ArgList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3075,6 +3625,11 @@ impl ArgList {
 pub struct Path {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for Path {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Path {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3105,6 +3660,11 @@ impl Path {
 pub struct PathSegment {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for PathSegment {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for PathSegment {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3144,6 +3704,11 @@ impl PathSegment {
 pub struct TypeArgList {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TypeArgList {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TypeArgList {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3180,6 +3745,11 @@ impl TypeArgList {
 pub struct TypeArg {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for TypeArg {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TypeArg {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3207,6 +3777,11 @@ impl TypeArg {
 pub struct AssocTypeArg {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for AssocTypeArg {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for AssocTypeArg {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3237,6 +3812,11 @@ impl AssocTypeArg {
 pub struct LifetimeArg {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for LifetimeArg {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for LifetimeArg {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3260,6 +3840,11 @@ impl LifetimeArg {}
 pub struct ConstArg {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for ConstArg {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ConstArg {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3290,6 +3875,11 @@ impl ConstArg {
 pub struct MacroItems {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for MacroItems {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for MacroItems {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3315,6 +3905,11 @@ impl MacroItems {}
 pub struct MacroStmts {
     pub(crate) syntax: SyntaxNode,
 }
+impl std::fmt::Display for MacroStmts {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for MacroStmts {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3362,6 +3957,11 @@ impl From<UnionDef> for NominalDef {
         NominalDef::UnionDef(node)
     }
 }
+impl std::fmt::Display for NominalDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for NominalDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3470,6 +4070,11 @@ impl From<DynTraitType> for TypeRef {
         TypeRef::DynTraitType(node)
     }
 }
+impl std::fmt::Display for TypeRef {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for TypeRef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3591,6 +4196,11 @@ impl From<Module> for ModuleItem {
         ModuleItem::Module(node)
     }
 }
+impl std::fmt::Display for ModuleItem {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ModuleItem {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3657,6 +4267,11 @@ impl From<ConstDef> for ImplItem {
         ImplItem::ConstDef(node)
     }
 }
+impl std::fmt::Display for ImplItem {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for ImplItem {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -3871,6 +4486,11 @@ impl From<BoxExpr> for Expr {
         Expr::BoxExpr(node)
     }
 }
+impl std::fmt::Display for Expr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Expr {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -4043,6 +4663,11 @@ impl From<LiteralPat> for Pat {
         Pat::LiteralPat(node)
     }
 }
+impl std::fmt::Display for Pat {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Pat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -4106,6 +4731,11 @@ impl From<TokenTree> for AttrInput {
         AttrInput::TokenTree(node)
     }
 }
+impl std::fmt::Display for AttrInput {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for AttrInput {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
@@ -4143,6 +4773,11 @@ impl From<LetStmt> for Stmt {
         Stmt::LetStmt(node)
     }
 }
+impl std::fmt::Display for Stmt {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl AstNode for Stmt {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
diff --git a/crates/ra_syntax/src/parsing/lexer.rs b/crates/ra_syntax/src/parsing/lexer.rs
index f2684c852..d1baaa607 100644
--- a/crates/ra_syntax/src/parsing/lexer.rs
+++ b/crates/ra_syntax/src/parsing/lexer.rs
@@ -65,7 +65,7 @@ pub fn tokenize(text: &str) -> (Vec<Token>, Vec<SyntaxError>) {
 /// Beware that unescape errors are not checked at tokenization time.
 pub fn lex_single_syntax_kind(text: &str) -> Option<(SyntaxKind, Option<SyntaxError>)> {
     lex_first_token(text)
-        .filter(|(token, _)| token.len.to_usize() == text.len())
+        .filter(|(token, _)| token.len == TextUnit::of_str(text))
         .map(|(token, error)| (token.kind, error))
 }
 
@@ -75,7 +75,7 @@ pub fn lex_single_syntax_kind(text: &str) -> Option<(SyntaxKind, Option<SyntaxEr
 /// Beware that unescape errors are not checked at tokenization time.
 pub fn lex_single_valid_syntax_kind(text: &str) -> Option<SyntaxKind> {
     lex_first_token(text)
-        .filter(|(token, error)| !error.is_some() && token.len.to_usize() == text.len())
+        .filter(|(token, error)| !error.is_some() && token.len == TextUnit::of_str(text))
         .map(|(token, _error)| token.kind)
 }
 
diff --git a/crates/ra_syntax/src/tests.rs b/crates/ra_syntax/src/tests.rs
index 912e6aec0..6a8cb6bb5 100644
--- a/crates/ra_syntax/src/tests.rs
+++ b/crates/ra_syntax/src/tests.rs
@@ -5,7 +5,7 @@ use std::{
 
 use test_utils::{collect_tests, dir_tests, project_dir, read_text};
 
-use crate::{fuzz, tokenize, SourceFile, SyntaxError, Token};
+use crate::{fuzz, tokenize, SourceFile, SyntaxError, TextRange, TextUnit, Token};
 
 #[test]
 fn lexer_tests() {
@@ -34,6 +34,7 @@ fn main() {
     "##;
 
     let parse = SourceFile::parse(code);
+    // eprintln!("{:#?}", parse.syntax_node());
     assert!(parse.ok().is_ok());
 }
 
@@ -120,11 +121,11 @@ fn assert_errors_are_absent(errors: &[SyntaxError], path: &Path) {
 
 fn dump_tokens_and_errors(tokens: &[Token], errors: &[SyntaxError], text: &str) -> String {
     let mut acc = String::new();
-    let mut offset = 0;
+    let mut offset = TextUnit::from_usize(0);
     for token in tokens {
-        let token_len = token.len.to_usize();
-        let token_text = &text[offset..offset + token_len];
-        offset += token_len;
+        let token_len = token.len;
+        let token_text = &text[TextRange::offset_len(offset, token.len)];
+        offset += token.len;
         writeln!(acc, "{:?} {} {:?}", token.kind, token_len, token_text).unwrap();
     }
     for err in errors {
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0032_fn_pointer_type.txt b/crates/ra_syntax/test_data/parser/inline/ok/0032_fn_pointer_type.txt
index a0a8aea76..4c17f0db8 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0032_fn_pointer_type.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0032_fn_pointer_type.txt
@@ -81,7 +81,8 @@ SOURCE_FILE@[0; 113)
         WHITESPACE@[97; 98) " "
         COMMA@[98; 99) ","
         WHITESPACE@[99; 100) " "
-        DOTDOTDOT@[100; 103) "..."
+        PARAM@[100; 103)
+          DOTDOTDOT@[100; 103) "..."
         WHITESPACE@[103; 104) " "
         R_PAREN@[104; 105) ")"
       WHITESPACE@[105; 106) " "
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0116_trait_fn_placeholder_parameter.rs b/crates/ra_syntax/test_data/parser/inline/ok/0116_trait_fn_placeholder_parameter.rs
deleted file mode 100644
index 472cb8803..000000000
--- a/crates/ra_syntax/test_data/parser/inline/ok/0116_trait_fn_placeholder_parameter.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-trait Foo {
-    fn bar(_: u64, mut x: i32);
-}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0116_trait_fn_placeholder_parameter.txt b/crates/ra_syntax/test_data/parser/inline/ok/0116_trait_fn_placeholder_parameter.txt
deleted file mode 100644
index 158236c5a..000000000
--- a/crates/ra_syntax/test_data/parser/inline/ok/0116_trait_fn_placeholder_parameter.txt
+++ /dev/null
@@ -1,47 +0,0 @@
-SOURCE_FILE@[0; 46)
-  TRAIT_DEF@[0; 45)
-    TRAIT_KW@[0; 5) "trait"
-    WHITESPACE@[5; 6) " "
-    NAME@[6; 9)
-      IDENT@[6; 9) "Foo"
-    WHITESPACE@[9; 10) " "
-    ITEM_LIST@[10; 45)
-      L_CURLY@[10; 11) "{"
-      WHITESPACE@[11; 16) "\n    "
-      FN_DEF@[16; 43)
-        FN_KW@[16; 18) "fn"
-        WHITESPACE@[18; 19) " "
-        NAME@[19; 22)
-          IDENT@[19; 22) "bar"
-        PARAM_LIST@[22; 42)
-          L_PAREN@[22; 23) "("
-          PARAM@[23; 29)
-            PLACEHOLDER_PAT@[23; 24)
-              UNDERSCORE@[23; 24) "_"
-            COLON@[24; 25) ":"
-            WHITESPACE@[25; 26) " "
-            PATH_TYPE@[26; 29)
-              PATH@[26; 29)
-                PATH_SEGMENT@[26; 29)
-                  NAME_REF@[26; 29)
-                    IDENT@[26; 29) "u64"
-          COMMA@[29; 30) ","
-          WHITESPACE@[30; 31) " "
-          PARAM@[31; 41)
-            BIND_PAT@[31; 36)
-              MUT_KW@[31; 34) "mut"
-              WHITESPACE@[34; 35) " "
-              NAME@[35; 36)
-                IDENT@[35; 36) "x"
-            COLON@[36; 37) ":"
-            WHITESPACE@[37; 38) " "
-            PATH_TYPE@[38; 41)
-              PATH@[38; 41)
-                PATH_SEGMENT@[38; 41)
-                  NAME_REF@[38; 41)
-                    IDENT@[38; 41) "i32"
-          R_PAREN@[41; 42) ")"
-        SEMI@[42; 43) ";"
-      WHITESPACE@[43; 44) "\n"
-      R_CURLY@[44; 45) "}"
-  WHITESPACE@[45; 46) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0123_param_list_vararg.txt b/crates/ra_syntax/test_data/parser/inline/ok/0123_param_list_vararg.txt
index 836e8e55b..6c3b17868 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0123_param_list_vararg.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0123_param_list_vararg.txt
@@ -32,7 +32,8 @@ SOURCE_FILE@[0; 57)
                       IDENT@[38; 40) "i8"
           COMMA@[40; 41) ","
           WHITESPACE@[41; 42) " "
-          DOTDOTDOT@[42; 45) "..."
+          PARAM@[42; 45)
+            DOTDOTDOT@[42; 45) "..."
           R_PAREN@[45; 46) ")"
         WHITESPACE@[46; 47) " "
         RET_TYPE@[47; 53)
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0156_fn_def_param.rs b/crates/ra_syntax/test_data/parser/inline/ok/0156_fn_def_param.rs
new file mode 100644
index 000000000..7b277c16b
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0156_fn_def_param.rs
@@ -0,0 +1 @@
+fn foo((x, y): (i32, i32)) {}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0156_fn_def_param.txt b/crates/ra_syntax/test_data/parser/inline/ok/0156_fn_def_param.txt
new file mode 100644
index 000000000..103e254a6
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0156_fn_def_param.txt
@@ -0,0 +1,44 @@
+SOURCE_FILE@[0; 30)
+  FN_DEF@[0; 29)
+    FN_KW@[0; 2) "fn"
+    WHITESPACE@[2; 3) " "
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 26)
+      L_PAREN@[6; 7) "("
+      PARAM@[7; 25)
+        TUPLE_PAT@[7; 13)
+          L_PAREN@[7; 8) "("
+          BIND_PAT@[8; 9)
+            NAME@[8; 9)
+              IDENT@[8; 9) "x"
+          COMMA@[9; 10) ","
+          WHITESPACE@[10; 11) " "
+          BIND_PAT@[11; 12)
+            NAME@[11; 12)
+              IDENT@[11; 12) "y"
+          R_PAREN@[12; 13) ")"
+        COLON@[13; 14) ":"
+        WHITESPACE@[14; 15) " "
+        TUPLE_TYPE@[15; 25)
+          L_PAREN@[15; 16) "("
+          PATH_TYPE@[16; 19)
+            PATH@[16; 19)
+              PATH_SEGMENT@[16; 19)
+                NAME_REF@[16; 19)
+                  IDENT@[16; 19) "i32"
+          COMMA@[19; 20) ","
+          WHITESPACE@[20; 21) " "
+          PATH_TYPE@[21; 24)
+            PATH@[21; 24)
+              PATH_SEGMENT@[21; 24)
+                NAME_REF@[21; 24)
+                  IDENT@[21; 24) "i32"
+          R_PAREN@[24; 25) ")"
+      R_PAREN@[25; 26) ")"
+    WHITESPACE@[26; 27) " "
+    BLOCK_EXPR@[27; 29)
+      BLOCK@[27; 29)
+        L_CURLY@[27; 28) "{"
+        R_CURLY@[28; 29) "}"
+  WHITESPACE@[29; 30) "\n"
diff --git a/crates/ra_syntax/test_data/parser/ok/0051_parameter_attrs.txt b/crates/ra_syntax/test_data/parser/ok/0051_parameter_attrs.txt
index 719c99c17..254eafc36 100644
--- a/crates/ra_syntax/test_data/parser/ok/0051_parameter_attrs.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0051_parameter_attrs.txt
@@ -118,7 +118,8 @@ SOURCE_FILE@[0; 519)
                   IDENT@[108; 112) "attr"
             R_BRACK@[112; 113) "]"
           WHITESPACE@[113; 114) " "
-          DOTDOTDOT@[114; 117) "..."
+          PARAM@[114; 117)
+            DOTDOTDOT@[114; 117) "..."
           R_PAREN@[117; 118) ")"
         WHITESPACE@[118; 119) " "
         RET_TYPE@[119; 125)
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0153_trait_fn_patterns.rs b/crates/ra_syntax/test_data/parser/ok/0063_trait_fn_patterns.rs
index a94bf378a..3b666af8e 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0153_trait_fn_patterns.rs
+++ b/crates/ra_syntax/test_data/parser/ok/0063_trait_fn_patterns.rs
@@ -3,4 +3,5 @@ trait T {
     fn f2(S { a, b }: S) {}
     fn f3(NewType(a): NewType) {}
     fn f4(&&a: &&usize) {}
+    fn bar(_: u64, mut x: i32);
 }
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0153_trait_fn_patterns.txt b/crates/ra_syntax/test_data/parser/ok/0063_trait_fn_patterns.txt
index b22df8dbe..eb2e3a503 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0153_trait_fn_patterns.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0063_trait_fn_patterns.txt
@@ -1,11 +1,11 @@
-SOURCE_FILE@[0; 138)
-  TRAIT_DEF@[0; 137)
+SOURCE_FILE@[0; 170)
+  TRAIT_DEF@[0; 169)
     TRAIT_KW@[0; 5) "trait"
     WHITESPACE@[5; 6) " "
     NAME@[6; 7)
       IDENT@[6; 7) "T"
     WHITESPACE@[7; 8) " "
-    ITEM_LIST@[8; 137)
+    ITEM_LIST@[8; 169)
       L_CURLY@[8; 9) "{"
       WHITESPACE@[9; 14) "\n    "
       FN_DEF@[14; 46)
@@ -156,6 +156,41 @@ SOURCE_FILE@[0; 138)
           BLOCK@[133; 135)
             L_CURLY@[133; 134) "{"
             R_CURLY@[134; 135) "}"
-      WHITESPACE@[135; 136) "\n"
-      R_CURLY@[136; 137) "}"
-  WHITESPACE@[137; 138) "\n"
+      WHITESPACE@[135; 140) "\n    "
+      FN_DEF@[140; 167)
+        FN_KW@[140; 142) "fn"
+        WHITESPACE@[142; 143) " "
+        NAME@[143; 146)
+          IDENT@[143; 146) "bar"
+        PARAM_LIST@[146; 166)
+          L_PAREN@[146; 147) "("
+          PARAM@[147; 153)
+            PLACEHOLDER_PAT@[147; 148)
+              UNDERSCORE@[147; 148) "_"
+            COLON@[148; 149) ":"
+            WHITESPACE@[149; 150) " "
+            PATH_TYPE@[150; 153)
+              PATH@[150; 153)
+                PATH_SEGMENT@[150; 153)
+                  NAME_REF@[150; 153)
+                    IDENT@[150; 153) "u64"
+          COMMA@[153; 154) ","
+          WHITESPACE@[154; 155) " "
+          PARAM@[155; 165)
+            BIND_PAT@[155; 160)
+              MUT_KW@[155; 158) "mut"
+              WHITESPACE@[158; 159) " "
+              NAME@[159; 160)
+                IDENT@[159; 160) "x"
+            COLON@[160; 161) ":"
+            WHITESPACE@[161; 162) " "
+            PATH_TYPE@[162; 165)
+              PATH@[162; 165)
+                PATH_SEGMENT@[162; 165)
+                  NAME_REF@[162; 165)
+                    IDENT@[162; 165) "i32"
+          R_PAREN@[165; 166) ")"
+        SEMI@[166; 167) ";"
+      WHITESPACE@[167; 168) "\n"
+      R_CURLY@[168; 169) "}"
+  WHITESPACE@[169; 170) "\n"
diff --git a/crates/ra_syntax/test_data/parser/ok/0063_variadic_fun.rs b/crates/ra_syntax/test_data/parser/ok/0063_variadic_fun.rs
new file mode 100644
index 000000000..a16afbaf3
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0063_variadic_fun.rs
@@ -0,0 +1,5 @@
+extern "C" {
+    fn a(_: *mut u8, ...,);
+    fn b(_: *mut u8, _: ...);
+    fn c(_: *mut u8, #[cfg(never)] [w, t, f]: ...,);
+}
diff --git a/crates/ra_syntax/test_data/parser/ok/0063_variadic_fun.txt b/crates/ra_syntax/test_data/parser/ok/0063_variadic_fun.txt
new file mode 100644
index 000000000..186f03626
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0063_variadic_fun.txt
@@ -0,0 +1,133 @@
+SOURCE_FILE@[0; 126)
+  EXTERN_BLOCK@[0; 125)
+    ABI@[0; 10)
+      EXTERN_KW@[0; 6) "extern"
+      WHITESPACE@[6; 7) " "
+      STRING@[7; 10) "\"C\""
+    WHITESPACE@[10; 11) " "
+    EXTERN_ITEM_LIST@[11; 125)
+      L_CURLY@[11; 12) "{"
+      WHITESPACE@[12; 17) "\n    "
+      FN_DEF@[17; 40)
+        FN_KW@[17; 19) "fn"
+        WHITESPACE@[19; 20) " "
+        NAME@[20; 21)
+          IDENT@[20; 21) "a"
+        PARAM_LIST@[21; 39)
+          L_PAREN@[21; 22) "("
+          PARAM@[22; 32)
+            PLACEHOLDER_PAT@[22; 23)
+              UNDERSCORE@[22; 23) "_"
+            COLON@[23; 24) ":"
+            WHITESPACE@[24; 25) " "
+            POINTER_TYPE@[25; 32)
+              STAR@[25; 26) "*"
+              MUT_KW@[26; 29) "mut"
+              WHITESPACE@[29; 30) " "
+              PATH_TYPE@[30; 32)
+                PATH@[30; 32)
+                  PATH_SEGMENT@[30; 32)
+                    NAME_REF@[30; 32)
+                      IDENT@[30; 32) "u8"
+          COMMA@[32; 33) ","
+          WHITESPACE@[33; 34) " "
+          PARAM@[34; 37)
+            DOTDOTDOT@[34; 37) "..."
+          COMMA@[37; 38) ","
+          R_PAREN@[38; 39) ")"
+        SEMI@[39; 40) ";"
+      WHITESPACE@[40; 45) "\n    "
+      FN_DEF@[45; 70)
+        FN_KW@[45; 47) "fn"
+        WHITESPACE@[47; 48) " "
+        NAME@[48; 49)
+          IDENT@[48; 49) "b"
+        PARAM_LIST@[49; 69)
+          L_PAREN@[49; 50) "("
+          PARAM@[50; 60)
+            PLACEHOLDER_PAT@[50; 51)
+              UNDERSCORE@[50; 51) "_"
+            COLON@[51; 52) ":"
+            WHITESPACE@[52; 53) " "
+            POINTER_TYPE@[53; 60)
+              STAR@[53; 54) "*"
+              MUT_KW@[54; 57) "mut"
+              WHITESPACE@[57; 58) " "
+              PATH_TYPE@[58; 60)
+                PATH@[58; 60)
+                  PATH_SEGMENT@[58; 60)
+                    NAME_REF@[58; 60)
+                      IDENT@[58; 60) "u8"
+          COMMA@[60; 61) ","
+          WHITESPACE@[61; 62) " "
+          PARAM@[62; 68)
+            PLACEHOLDER_PAT@[62; 63)
+              UNDERSCORE@[62; 63) "_"
+            COLON@[63; 64) ":"
+            WHITESPACE@[64; 65) " "
+            DOTDOTDOT@[65; 68) "..."
+          R_PAREN@[68; 69) ")"
+        SEMI@[69; 70) ";"
+      WHITESPACE@[70; 75) "\n    "
+      FN_DEF@[75; 123)
+        FN_KW@[75; 77) "fn"
+        WHITESPACE@[77; 78) " "
+        NAME@[78; 79)
+          IDENT@[78; 79) "c"
+        PARAM_LIST@[79; 122)
+          L_PAREN@[79; 80) "("
+          PARAM@[80; 90)
+            PLACEHOLDER_PAT@[80; 81)
+              UNDERSCORE@[80; 81) "_"
+            COLON@[81; 82) ":"
+            WHITESPACE@[82; 83) " "
+            POINTER_TYPE@[83; 90)
+              STAR@[83; 84) "*"
+              MUT_KW@[84; 87) "mut"
+              WHITESPACE@[87; 88) " "
+              PATH_TYPE@[88; 90)
+                PATH@[88; 90)
+                  PATH_SEGMENT@[88; 90)
+                    NAME_REF@[88; 90)
+                      IDENT@[88; 90) "u8"
+          COMMA@[90; 91) ","
+          WHITESPACE@[91; 92) " "
+          ATTR@[92; 105)
+            POUND@[92; 93) "#"
+            L_BRACK@[93; 94) "["
+            PATH@[94; 97)
+              PATH_SEGMENT@[94; 97)
+                NAME_REF@[94; 97)
+                  IDENT@[94; 97) "cfg"
+            TOKEN_TREE@[97; 104)
+              L_PAREN@[97; 98) "("
+              IDENT@[98; 103) "never"
+              R_PAREN@[103; 104) ")"
+            R_BRACK@[104; 105) "]"
+          WHITESPACE@[105; 106) " "
+          PARAM@[106; 120)
+            SLICE_PAT@[106; 115)
+              L_BRACK@[106; 107) "["
+              BIND_PAT@[107; 108)
+                NAME@[107; 108)
+                  IDENT@[107; 108) "w"
+              COMMA@[108; 109) ","
+              WHITESPACE@[109; 110) " "
+              BIND_PAT@[110; 111)
+                NAME@[110; 111)
+                  IDENT@[110; 111) "t"
+              COMMA@[111; 112) ","
+              WHITESPACE@[112; 113) " "
+              BIND_PAT@[113; 114)
+                NAME@[113; 114)
+                  IDENT@[113; 114) "f"
+              R_BRACK@[114; 115) "]"
+            COLON@[115; 116) ":"
+            WHITESPACE@[116; 117) " "
+            DOTDOTDOT@[117; 120) "..."
+          COMMA@[120; 121) ","
+          R_PAREN@[121; 122) ")"
+        SEMI@[122; 123) ";"
+      WHITESPACE@[123; 124) "\n"
+      R_CURLY@[124; 125) "}"
+  WHITESPACE@[125; 126) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0152_fn_patterns.rs b/crates/ra_syntax/test_data/parser/ok/0064_impl_fn_params.rs
index b49e872d7..b49e872d7 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0152_fn_patterns.rs
+++ b/crates/ra_syntax/test_data/parser/ok/0064_impl_fn_params.rs
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0152_fn_patterns.txt b/crates/ra_syntax/test_data/parser/ok/0064_impl_fn_params.txt
index b30030de3..b30030de3 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0152_fn_patterns.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0064_impl_fn_params.txt
diff --git a/crates/ra_text_edit/src/text_edit.rs b/crates/ra_text_edit/src/text_edit.rs
index 3291ada42..5c37a08a8 100644
--- a/crates/ra_text_edit/src/text_edit.rs
+++ b/crates/ra_text_edit/src/text_edit.rs
@@ -63,12 +63,12 @@ impl TextEdit {
     }
 
     pub fn apply(&self, text: &str) -> String {
-        let mut total_len = text.len();
+        let mut total_len = TextUnit::of_str(text);
         for atom in self.atoms.iter() {
-            total_len += atom.insert.len();
-            total_len -= (atom.delete.end() - atom.delete.start()).to_usize();
+            total_len += TextUnit::of_str(&atom.insert);
+            total_len -= atom.delete.end() - atom.delete.start();
         }
-        let mut buf = String::with_capacity(total_len);
+        let mut buf = String::with_capacity(total_len.to_usize());
         let mut prev = 0;
         for atom in self.atoms.iter() {
             let start = atom.delete.start().to_usize();
@@ -80,7 +80,7 @@ impl TextEdit {
             prev = end;
         }
         buf.push_str(&text[prev..text.len()]);
-        assert_eq!(buf.len(), total_len);
+        assert_eq!(TextUnit::of_str(&buf), total_len);
         buf
     }
 
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index cfca06f56..6b9a11a87 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -30,7 +30,11 @@ pub struct ServerConfig {
 
     pub lru_capacity: Option<usize>,
 
-    pub max_inlay_hint_length: Option<usize>,
+    #[serde(deserialize_with = "nullable_bool_true")]
+    pub inlay_hints_type: bool,
+    #[serde(deserialize_with = "nullable_bool_true")]
+    pub inlay_hints_parameter: bool,
+    pub inlay_hints_max_length: Option<usize>,
 
     pub cargo_watch_enable: bool,
     pub cargo_watch_args: Vec<String>,
@@ -63,7 +67,9 @@ impl Default for ServerConfig {
             exclude_globs: Vec::new(),
             use_client_watching: false,
             lru_capacity: None,
-            max_inlay_hint_length: None,
+            inlay_hints_type: true,
+            inlay_hints_parameter: true,
+            inlay_hints_max_length: None,
             cargo_watch_enable: true,
             cargo_watch_args: Vec::new(),
             cargo_watch_command: "check".to_string(),
diff --git a/crates/rust-analyzer/src/conv.rs b/crates/rust-analyzer/src/conv.rs
index a2d68c344..fd4657d7e 100644
--- a/crates/rust-analyzer/src/conv.rs
+++ b/crates/rust-analyzer/src/conv.rs
@@ -11,8 +11,8 @@ use lsp_types::{
 use ra_ide::{
     translate_offset_with_edit, CompletionItem, CompletionItemKind, FileId, FilePosition,
     FileRange, FileSystemEdit, Fold, FoldKind, Highlight, HighlightModifier, HighlightTag,
-    InsertTextFormat, LineCol, LineIndex, NavigationTarget, RangeInfo, ReferenceAccess, Severity,
-    SourceChange, SourceFileEdit,
+    InlayHint, InlayKind, InsertTextFormat, LineCol, LineIndex, NavigationTarget, RangeInfo,
+    ReferenceAccess, Severity, SourceChange, SourceFileEdit,
 };
 use ra_syntax::{SyntaxKind, TextRange, TextUnit};
 use ra_text_edit::{AtomTextEdit, TextEdit};
@@ -323,6 +323,20 @@ impl ConvWith<&FoldConvCtx<'_>> for Fold {
     }
 }
 
+impl ConvWith<&LineIndex> for InlayHint {
+    type Output = req::InlayHint;
+    fn conv_with(self, line_index: &LineIndex) -> Self::Output {
+        req::InlayHint {
+            label: self.label.to_string(),
+            range: self.range.conv_with(line_index),
+            kind: match self.kind {
+                InlayKind::ParameterHint => req::InlayKind::ParameterHint,
+                InlayKind::TypeHint => req::InlayKind::TypeHint,
+            },
+        }
+    }
+}
+
 impl Conv for Highlight {
     type Output = (u32, u32);
 
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index b4add046f..eb29e8322 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -18,7 +18,7 @@ use crossbeam_channel::{select, unbounded, RecvError, Sender};
 use lsp_server::{Connection, ErrorCode, Message, Notification, Request, RequestId, Response};
 use lsp_types::{ClientCapabilities, NumberOrString};
 use ra_cargo_watch::{url_from_path_with_drive_lowercasing, CheckOptions, CheckTask};
-use ra_ide::{Canceled, FileId, LibraryData, SourceRootId};
+use ra_ide::{Canceled, FileId, InlayHintsOptions, LibraryData, SourceRootId};
 use ra_prof::profile;
 use ra_vfs::{VfsFile, VfsTask, Watch};
 use relative_path::RelativePathBuf;
@@ -177,7 +177,11 @@ pub fn main_loop(
                     .and_then(|it| it.folding_range.as_ref())
                     .and_then(|it| it.line_folding_only)
                     .unwrap_or(false),
-                max_inlay_hint_length: config.max_inlay_hint_length,
+                inlay_hints: InlayHintsOptions {
+                    type_hints: config.inlay_hints_type,
+                    parameter_hints: config.inlay_hints_parameter,
+                    max_length: config.inlay_hints_max_length,
+                },
                 cargo_watch: CheckOptions {
                     enable: config.cargo_watch_enable,
                     args: config.cargo_watch_args,
diff --git a/crates/rust-analyzer/src/main_loop/handlers.rs b/crates/rust-analyzer/src/main_loop/handlers.rs
index 571a896f3..df3622d61 100644
--- a/crates/rust-analyzer/src/main_loop/handlers.rs
+++ b/crates/rust-analyzer/src/main_loop/handlers.rs
@@ -37,7 +37,7 @@ use crate::{
     },
     diagnostics::DiagnosticTask,
     from_json,
-    req::{self, Decoration, InlayHint, InlayHintsParams, InlayKind},
+    req::{self, Decoration, InlayHint, InlayHintsParams},
     semantic_tokens::SemanticTokensBuilder,
     world::WorldSnapshot,
     LspError, Result,
@@ -1017,16 +1017,9 @@ pub fn handle_inlay_hints(
     let analysis = world.analysis();
     let line_index = analysis.file_line_index(file_id)?;
     Ok(analysis
-        .inlay_hints(file_id, world.options.max_inlay_hint_length)?
+        .inlay_hints(file_id, &world.options.inlay_hints)?
         .into_iter()
-        .map(|api_type| InlayHint {
-            label: api_type.label.to_string(),
-            range: api_type.range.conv_with(&line_index),
-            kind: match api_type.kind {
-                ra_ide::InlayKind::TypeHint => InlayKind::TypeHint,
-                ra_ide::InlayKind::ParameterHint => InlayKind::ParameterHint,
-            },
-        })
+        .map_conv_with(&line_index)
         .collect())
 }
 
diff --git a/crates/rust-analyzer/src/world.rs b/crates/rust-analyzer/src/world.rs
index a4fda9f80..5743471bf 100644
--- a/crates/rust-analyzer/src/world.rs
+++ b/crates/rust-analyzer/src/world.rs
@@ -13,7 +13,8 @@ use lsp_types::Url;
 use parking_lot::RwLock;
 use ra_cargo_watch::{url_from_path_with_drive_lowercasing, CheckOptions, CheckWatcher};
 use ra_ide::{
-    Analysis, AnalysisChange, AnalysisHost, CrateGraph, FileId, LibraryData, SourceRootId,
+    Analysis, AnalysisChange, AnalysisHost, CrateGraph, FileId, InlayHintsOptions, LibraryData,
+    SourceRootId,
 };
 use ra_project_model::{get_rustc_cfg_options, ProjectWorkspace};
 use ra_vfs::{LineEndings, RootEntry, Vfs, VfsChange, VfsFile, VfsRoot, VfsTask, Watch};
@@ -34,7 +35,7 @@ pub struct Options {
     pub publish_decorations: bool,
     pub supports_location_link: bool,
     pub line_folding_only: bool,
-    pub max_inlay_hint_length: Option<usize>,
+    pub inlay_hints: InlayHintsOptions,
     pub rustfmt_args: Vec<String>,
     pub cargo_watch: CheckOptions,
     pub vscode_lldb: bool,
diff --git a/crates/test_utils/src/lib.rs b/crates/test_utils/src/lib.rs
index a0d8f4d37..db03df1c4 100644
--- a/crates/test_utils/src/lib.rs
+++ b/crates/test_utils/src/lib.rs
@@ -397,6 +397,8 @@ pub fn skip_slow_tests() -> bool {
     should_skip
 }
 
+const REWRITE: bool = false;
+
 /// Asserts that `expected` and `actual` strings are equal. If they differ only
 /// in trailing or leading whitespace the test won't fail and
 /// the contents of `actual` will be written to the file located at `path`.
@@ -412,7 +414,6 @@ fn assert_equal_text(expected: &str, actual: &str, path: &Path) {
         fs::write(path, actual).unwrap();
         return;
     }
-    const REWRITE: bool = false;
     if REWRITE {
         println!("rewriting {}", pretty_path.display());
         fs::write(path, actual).unwrap();
diff --git a/docs/user/features.md b/docs/user/features.md
index ba4d50fa8..45360c633 100644
--- a/docs/user/features.md
+++ b/docs/user/features.md
@@ -191,8 +191,9 @@ Two types of inlay hints are displayed currently:
 
 In VS Code, the following settings can be used to configure the inlay hints:
 
-* `rust-analyzer.displayInlayHints` — toggles inlay hints display on or off
-* `rust-analyzer.maxInlayHintLength` — shortens the hints if their length exceeds the value specified. If no value is specified (`null`), no shortening is applied.
+* `rust-analyzer.inlayHints.typeHints` - enable hints for inferred types.
+* `rust-analyzer.inlayHints.parameterHints` - enable hints for function parameters.
+* `rust-analyzer.inlayHints.maxLength` — shortens the hints if their length exceeds the value specified. If no value is specified (`null`), no shortening is applied.
 
 **Note:** VS Code does not have native support for inlay hints [yet](https://github.com/microsoft/vscode/issues/16221) and the hints are implemented using decorations.
 This approach has limitations, the caret movement and bracket highlighting near the edges of the hint may be weird:
diff --git a/editors/code/package.json b/editors/code/package.json
index 1fe8e9f8a..3aaae357a 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -261,7 +261,7 @@
                 "rust-analyzer.cargo-watch.enable": {
                     "type": "boolean",
                     "default": true,
-                    "markdownDescription": "Run `cargo check` for diagnostics on save"
+                    "markdownDescription": "Run specified `cargo-watch` command for diagnostics on save"
                 },
                 "rust-analyzer.cargo-watch.arguments": {
                     "type": "array",
@@ -312,12 +312,17 @@
                     "exclusiveMinimum": true,
                     "description": "Number of syntax trees rust-analyzer keeps in memory"
                 },
-                "rust-analyzer.displayInlayHints": {
+                "rust-analyzer.inlayHints.typeHints": {
                     "type": "boolean",
                     "default": true,
-                    "description": "Display additional type and parameter information in the editor"
+                    "description": "Whether to show inlay type hints"
                 },
-                "rust-analyzer.maxInlayHintLength": {
+                "rust-analyzer.inlayHints.parameterHints": {
+                    "type": "boolean",
+                    "default": true,
+                    "description": "Whether to show function parameter name inlay hints at the call site"
+                },
+                "rust-analyzer.inlayHints.maxLength": {
                     "type": [
                         "null",
                         "integer"
diff --git a/editors/code/src/client.ts b/editors/code/src/client.ts
index 99c9c5ae7..d65454275 100644
--- a/editors/code/src/client.ts
+++ b/editors/code/src/client.ts
@@ -29,11 +29,16 @@ export async function createClient(config: Config, serverPath: string): Promise<
         initializationOptions: {
             publishDecorations: !config.highlightingSemanticTokens,
             lruCapacity: config.lruCapacity,
-            maxInlayHintLength: config.maxInlayHintLength,
+
+            inlayHintsType: config.inlayHints.typeHints,
+            inlayHintsParameter: config.inlayHints.parameterHints,
+            inlayHintsMaxLength: config.inlayHints.maxLength,
+
             cargoWatchEnable: cargoWatchOpts.enable,
             cargoWatchArgs: cargoWatchOpts.arguments,
             cargoWatchCommand: cargoWatchOpts.command,
             cargoWatchAllTargets: cargoWatchOpts.allTargets,
+
             excludeGlobs: config.excludeGlobs,
             useClientWatching: config.useClientWatching,
             featureFlags: config.featureFlags,
diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index 3ade7e900..6db073bec 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -5,6 +5,12 @@ import { log } from "./util";
 
 const RA_LSP_DEBUG = process.env.__RA_LSP_SERVER_DEBUG;
 
+export interface InlayHintOptions {
+    typeHints: boolean;
+    parameterHints: boolean;
+    maxLength: number | null;
+}
+
 export interface CargoWatchOptions {
     enable: boolean;
     arguments: string[];
@@ -22,7 +28,8 @@ export class Config {
     private static readonly requiresReloadOpts = [
         "cargoFeatures",
         "cargo-watch",
-        "highlighting.semanticTokens"
+        "highlighting.semanticTokens",
+        "inlayHints",
     ]
         .map(opt => `${Config.rootSection}.${opt}`);
 
@@ -149,8 +156,13 @@ export class Config {
     get highlightingOn() { return this.cfg.get("highlightingOn") as boolean; }
     get rainbowHighlightingOn() { return this.cfg.get("rainbowHighlightingOn") as boolean; }
     get lruCapacity() { return this.cfg.get("lruCapacity") as null | number; }
-    get displayInlayHints() { return this.cfg.get("displayInlayHints") as boolean; }
-    get maxInlayHintLength() { return this.cfg.get("maxInlayHintLength") as number; }
+    get inlayHints(): InlayHintOptions {
+        return {
+            typeHints: this.cfg.get("inlayHints.typeHints") as boolean,
+            parameterHints: this.cfg.get("inlayHints.parameterHints") as boolean,
+            maxLength: this.cfg.get("inlayHints.maxLength") as null | number,
+        };
+    }
     get excludeGlobs() { return this.cfg.get("excludeGlobs") as string[]; }
     get useClientWatching() { return this.cfg.get("useClientWatching") as boolean; }
     get featureFlags() { return this.cfg.get("featureFlags") as Record<string, boolean>; }
diff --git a/editors/code/src/inlay_hints.ts b/editors/code/src/inlay_hints.ts
index e1a82e03e..b19b09ad5 100644
--- a/editors/code/src/inlay_hints.ts
+++ b/editors/code/src/inlay_hints.ts
@@ -10,7 +10,7 @@ export function activateInlayHints(ctx: Ctx) {
     const maybeUpdater = {
         updater: null as null | HintsUpdater,
         onConfigChange() {
-            if (!ctx.config.displayInlayHints) {
+            if (!ctx.config.inlayHints.typeHints && !ctx.config.inlayHints.parameterHints) {
                 return this.dispose();
             }
             if (!this.updater) this.updater = new HintsUpdater(ctx);
diff --git a/xtask/src/codegen/gen_syntax.rs b/xtask/src/codegen/gen_syntax.rs
index db05dcebb..32afd47bc 100644
--- a/xtask/src/codegen/gen_syntax.rs
+++ b/xtask/src/codegen/gen_syntax.rs
@@ -68,6 +68,12 @@ fn generate_ast(grammar: AstSrc<'_>) -> Result<String> {
                 pub(crate) syntax: SyntaxNode,
             }
 
+            impl std::fmt::Display for #name {
+                fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+                    std::fmt::Display::fmt(self.syntax(), f)
+                }
+            }
+
             impl AstNode for #name {
                 fn can_cast(kind: SyntaxKind) -> bool {
                     match kind {
@@ -114,6 +120,12 @@ fn generate_ast(grammar: AstSrc<'_>) -> Result<String> {
             }
             )*
 
+            impl std::fmt::Display for #name {
+                fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+                    std::fmt::Display::fmt(self.syntax(), f)
+                }
+            }
+
             impl AstNode for #name {
                 fn can_cast(kind: SyntaxKind) -> bool {
                     match kind {
diff --git a/xtask/src/lib.rs b/xtask/src/lib.rs
index 014b61b37..e1472e85d 100644
--- a/xtask/src/lib.rs
+++ b/xtask/src/lib.rs
@@ -38,13 +38,11 @@ pub fn project_root() -> PathBuf {
 }
 
 pub fn run_rustfmt(mode: Mode) -> Result<()> {
+    let _dir = pushd(project_root());
     ensure_rustfmt()?;
 
-    if mode == Mode::Verify {
-        run!("rustup run {} -- cargo fmt -- --check", TOOLCHAIN)?;
-    } else {
-        run!("rustup run {} -- cargo fmt", TOOLCHAIN)?;
-    }
+    let check = if mode == Mode::Verify { "--check" } else { "" };
+    run!("rustup run {} -- cargo fmt -- {}", TOOLCHAIN, check)?;
     Ok(())
 }