182 files changed, 1120 insertions, 466 deletions
diff --git a/crates/ra_assists/src/assists/auto_import.rs b/crates/ra_assists/src/assists/auto_import.rs
index 2629f00e6..2068256b0 100644
--- a/crates/ra_assists/src/assists/auto_import.rs
+++ b/crates/ra_assists/src/assists/auto_import.rs
@@ -1,7 +1,6 @@
 use hir::{db::HirDatabase, ModPath};
 use ra_syntax::{
    ast::{self, AstNode},
-    SyntaxKind::USE_ITEM,
    SyntaxNode,
 };
@@ -33,9 +32,11 @@ pub(crate) fn auto_import<F: ImportsLocator>(
 ) -> Option<Assist> {
    let path_to_import: ast::Path = ctx.find_node_at_offset()?;
    let path_to_import_syntax = path_to_import.syntax();
-    if path_to_import_syntax.ancestors().find(|ancestor| ancestor.kind() == USE_ITEM).is_some() {
+    if path_to_import_syntax.ancestors().find_map(ast::UseItem::cast).is_some() {
        return None;
    }
+    let name_to_import =
+        path_to_import_syntax.descendants().find_map(ast::NameRef::cast)?.syntax().to_string();
    let module = path_to_import_syntax.ancestors().find_map(ast::Module::cast);
    let position = match module.and_then(|it| it.item_list()) {
@@ -52,7 +53,7 @@ pub(crate) fn auto_import<F: ImportsLocator>(
    }
    let proposed_imports = imports_locator
-        .find_imports(&path_to_import_syntax.to_string())
+        .find_imports(&name_to_import)
        .into_iter()
        .filter_map(|module_def| module_with_name_to_import.find_use_path(ctx.db, module_def))
        .filter(|use_path| !use_path.segments.is_empty())
@@ -62,16 +63,12 @@ pub(crate) fn auto_import<F: ImportsLocator>(
        return None;
    }
-    ctx.add_assist_group(
+    ctx.add_assist_group(AssistId("auto_import"), format!("Import {}", name_to_import), || {
-        AssistId("auto_import"),
+        proposed_imports
-        format!("Import {}", path_to_import_syntax),
+            .into_iter()
-        || {
+            .map(|import| import_to_action(import, &position, &path_to_import_syntax))
-            proposed_imports
+            .collect()
-                .into_iter()
+    })
-                .map(|import| import_to_action(import, &position, &path_to_import_syntax))
-                .collect()
-        },
-    )
 }
 fn import_to_action(import: ModPath, position: &SyntaxNode, anchor: &SyntaxNode) -> ActionBuilder {
@@ -121,21 +118,29 @@ mod tests {
            r"
            use PubMod::PubStruct1;
-            PubStruct2<|>
+            struct Test {
+                test: Pub<|>Struct2<u8>,
+            }
            pub mod PubMod {
                pub struct PubStruct1;
-                pub struct PubStruct2;
+                pub struct PubStruct2<T> {
+                    _t: T,
+                }
            }
            ",
            r"
            use PubMod::{PubStruct2, PubStruct1};
-            PubStruct2<|>
+            struct Test {
+                test: Pub<|>Struct2<u8>,
+            }
            pub mod PubMod {
                pub struct PubStruct1;
-                pub struct PubStruct2;
+                pub struct PubStruct2<T> {
+                    _t: T,
+                }
            }
            ",
        );
diff --git a/crates/ra_cargo_watch/src/conv.rs b/crates/ra_cargo_watch/src/conv.rs
index 8fba400ae..506370535 100644
--- a/crates/ra_cargo_watch/src/conv.rs
+++ b/crates/ra_cargo_watch/src/conv.rs
@@ -1,12 +1,11 @@
 //! This module provides the functionality needed to convert diagnostics from
 //! `cargo check` json format to the LSP diagnostic format.
 use cargo_metadata::diagnostic::{
-    Applicability, Diagnostic as RustDiagnostic, DiagnosticLevel, DiagnosticSpan,
+    Diagnostic as RustDiagnostic, DiagnosticLevel, DiagnosticSpan, DiagnosticSpanMacroExpansion,
-    DiagnosticSpanMacroExpansion,
 };
 use lsp_types::{
-    Diagnostic, DiagnosticRelatedInformation, DiagnosticSeverity, DiagnosticTag, Location,
+    CodeAction, Diagnostic, DiagnosticRelatedInformation, DiagnosticSeverity, DiagnosticTag,
-    NumberOrString, Position, Range, Url,
+    Location, NumberOrString, Position, Range, TextEdit, Url, WorkspaceEdit,
 };
 use std::{
    fmt::Write,
@@ -117,38 +116,9 @@ fn is_deprecated(rd: &RustDiagnostic) -> bool {
    }
 }
-#[derive(Clone, Debug)]
-pub struct SuggestedFix {
-    pub title: String,
-    pub location: Location,
-    pub replacement: String,
-    pub applicability: Applicability,
-    pub diagnostics: Vec<Diagnostic>,
-}
-impl std::cmp::PartialEq<SuggestedFix> for SuggestedFix {
-    fn eq(&self, other: &SuggestedFix) -> bool {
-        if self.title == other.title
-            && self.location == other.location
-            && self.replacement == other.replacement
-        {
-            // Applicability doesn't impl PartialEq...
-            match (&self.applicability, &other.applicability) {
-                (Applicability::MachineApplicable, Applicability::MachineApplicable) => true,
-                (Applicability::HasPlaceholders, Applicability::HasPlaceholders) => true,
-                (Applicability::MaybeIncorrect, Applicability::MaybeIncorrect) => true,
-                (Applicability::Unspecified, Applicability::Unspecified) => true,
-                _ => false,
-            }
-        } else {
-            false
-        }
-    }
-}
 enum MappedRustChildDiagnostic {
    Related(DiagnosticRelatedInformation),
-    SuggestedFix(SuggestedFix),
+    SuggestedFix(CodeAction),
    MessageLine(String),
 }
@@ -176,12 +146,20 @@ fn map_rust_child_diagnostic(
            rd.message.clone()
        };
-        MappedRustChildDiagnostic::SuggestedFix(SuggestedFix {
+        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)
+        };
+        MappedRustChildDiagnostic::SuggestedFix(CodeAction {
            title,
-            location,
+            kind: Some("quickfix".to_string()),
-            replacement: suggested_replacement.clone(),
+            diagnostics: None,
-            applicability: span.suggestion_applicability.clone().unwrap_or(Applicability::Unknown),
+            edit: Some(edit),
-            diagnostics: vec![],
+            command: None,
+            is_preferred: None,
        })
    } else {
        MappedRustChildDiagnostic::Related(DiagnosticRelatedInformation {
@@ -195,7 +173,7 @@ fn map_rust_child_diagnostic(
 pub(crate) struct MappedRustDiagnostic {
    pub location: Location,
    pub diagnostic: Diagnostic,
-    pub suggested_fixes: Vec<SuggestedFix>,
+    pub fixes: Vec<CodeAction>,
 }
 /// Converts a Rust root diagnostic to LSP form
@@ -250,15 +228,13 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
        }
    }
-    let mut suggested_fixes = vec![];
+    let mut fixes = vec![];
    let mut message = rd.message.clone();
    for child in &rd.children {
        let child = map_rust_child_diagnostic(&child, workspace_root);
        match child {
            MappedRustChildDiagnostic::Related(related) => related_information.push(related),
-            MappedRustChildDiagnostic::SuggestedFix(suggested_fix) => {
+            MappedRustChildDiagnostic::SuggestedFix(code_action) => fixes.push(code_action.into()),
-                suggested_fixes.push(suggested_fix)
-            }
            MappedRustChildDiagnostic::MessageLine(message_line) => {
                write!(&mut message, "\n{}", message_line).unwrap();
@@ -295,7 +271,7 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
        tags: if !tags.is_empty() { Some(tags) } else { None },
    };
-    Some(MappedRustDiagnostic { location, diagnostic, suggested_fixes })
+    Some(MappedRustDiagnostic { location, diagnostic, fixes })
 }
 /// 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 cb0920914..95ca163dc 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
@@ -61,25 +61,39 @@ MappedRustDiagnostic {
        ),
        tags: None,
    },
-    suggested_fixes: [
+    fixes: [
-        SuggestedFix {
+        CodeAction {
            title: "consider passing by value instead: \'self\'",
-            location: Location {
+            kind: Some(
-                uri: "file:///test/compiler/mir/tagset.rs",
+                "quickfix",
-                range: Range {
+            ),
-                    start: Position {
+            diagnostics: None,
-                        line: 41,
+            edit: Some(
-                        character: 23,
+                WorkspaceEdit {
-                    },
+                    changes: Some(
-                    end: Position {
+                        {
-                        line: 41,
+                            "file:///test/compiler/mir/tagset.rs": [
-                        character: 28,
+                                TextEdit {
-                    },
+                                    range: Range {
+                                        start: Position {
+                                            line: 41,
+                                            character: 23,
+                                        },
+                                        end: Position {
+                                            line: 41,
+                                            character: 28,
+                                        },
+                                    },
+                                    new_text: "self",
+                                },
+                            ],
+                        },
+                    ),
+                    document_changes: None,
                },
-            },
+            ),
-            replacement: "self",
+            command: None,
-            applicability: Unspecified,
+            is_preferred: None,
-            diagnostics: [],
        },
    ],
 }
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 19510ecc1..12eb32df4 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
@@ -42,5 +42,5 @@ MappedRustDiagnostic {
        related_information: None,
        tags: None,
    },
-    suggested_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 92f7eec05..7b83a7cd0 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
@@ -57,5 +57,5 @@ MappedRustDiagnostic {
        ),
        tags: None,
    },
-    suggested_fixes: [],
+    fixes: [],
 }
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 cf683e4b6..54679c5db 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
@@ -42,5 +42,5 @@ MappedRustDiagnostic {
        related_information: None,
        tags: None,
    },
-    suggested_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 8c1483c74..57df4ceaf 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
@@ -42,5 +42,5 @@ MappedRustDiagnostic {
        related_information: None,
        tags: None,
    },
-    suggested_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 eb5a2247b..3e1fe736c 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
@@ -46,25 +46,39 @@ MappedRustDiagnostic {
            ],
        ),
    },
-    suggested_fixes: [
+    fixes: [
-        SuggestedFix {
+        CodeAction {
            title: "consider prefixing with an underscore: \'_foo\'",
-            location: Location {
+            kind: Some(
-                uri: "file:///test/driver/subcommand/repl.rs",
+                "quickfix",
-                range: Range {
+            ),
-                    start: Position {
+            diagnostics: None,
-                        line: 290,
+            edit: Some(
-                        character: 8,
+                WorkspaceEdit {
-                    },
+                    changes: Some(
-                    end: Position {
+                        {
-                        line: 290,
+                            "file:///test/driver/subcommand/repl.rs": [
-                        character: 11,
+                                TextEdit {
-                    },
+                                    range: Range {
+                                        start: Position {
+                                            line: 290,
+                                            character: 8,
+                                        },
+                                        end: Position {
+                                            line: 290,
+                                            character: 11,
+                                        },
+                                    },
+                                    new_text: "_foo",
+                                },
+                            ],
+                        },
+                    ),
+                    document_changes: None,
                },
-            },
+            ),
-            replacement: "_foo",
+            command: None,
-            applicability: MachineApplicable,
+            is_preferred: None,
-            diagnostics: [],
        },
    ],
 }
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 2f4518931..69301078d 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
@@ -61,5 +61,5 @@ MappedRustDiagnostic {
        ),
        tags: None,
    },
-    suggested_fixes: [],
+    fixes: [],
 }
diff --git a/crates/ra_cargo_watch/src/lib.rs b/crates/ra_cargo_watch/src/lib.rs
index a718a5e52..f07c34549 100644
--- a/crates/ra_cargo_watch/src/lib.rs
+++ b/crates/ra_cargo_watch/src/lib.rs
@@ -4,22 +4,20 @@
 use cargo_metadata::Message;
 use crossbeam_channel::{never, select, unbounded, Receiver, RecvError, Sender};
 use lsp_types::{
-    Diagnostic, Url, WorkDoneProgress, WorkDoneProgressBegin, WorkDoneProgressEnd,
+    CodeAction, CodeActionOrCommand, Diagnostic, Url, WorkDoneProgress, WorkDoneProgressBegin,
-    WorkDoneProgressReport,
+    WorkDoneProgressEnd, WorkDoneProgressReport,
 };
 use std::{
-    collections::HashMap,
    io::{BufRead, BufReader},
    path::PathBuf,
    process::{Command, Stdio},
-    sync::Arc,
    thread::JoinHandle,
    time::Instant,
 };
 mod conv;
-use crate::conv::{map_rust_diagnostic_to_lsp, MappedRustDiagnostic, SuggestedFix};
+use crate::conv::{map_rust_diagnostic_to_lsp, MappedRustDiagnostic};
 pub use crate::conv::url_from_path_with_drive_lowercasing;
@@ -38,7 +36,6 @@ pub struct CheckOptions {
 #[derive(Debug)]
 pub struct CheckWatcher {
    pub task_recv: Receiver<CheckTask>,
-    pub state: Arc<CheckState>,
    cmd_send: Option<Sender<CheckCommand>>,
    handle: Option<JoinHandle<()>>,
 }
@@ -46,7 +43,6 @@ pub struct CheckWatcher {
 impl CheckWatcher {
    pub fn new(options: &CheckOptions, workspace_root: PathBuf) -> CheckWatcher {
        let options = options.clone();
-        let state = Arc::new(CheckState::new());
        let (task_send, task_recv) = unbounded::<CheckTask>();
        let (cmd_send, cmd_recv) = unbounded::<CheckCommand>();
@@ -54,13 +50,12 @@ impl CheckWatcher {
            let mut check = CheckWatcherThread::new(options, workspace_root);
            check.run(&task_send, &cmd_recv);
        });
-        CheckWatcher { task_recv, cmd_send: Some(cmd_send), handle: Some(handle), state }
+        CheckWatcher { task_recv, cmd_send: Some(cmd_send), handle: Some(handle) }
    }
    /// Returns a CheckWatcher that doesn't actually do anything
    pub fn dummy() -> CheckWatcher {
-        let state = Arc::new(CheckState::new());
+        CheckWatcher { task_recv: never(), cmd_send: None, handle: None }
-        CheckWatcher { task_recv: never(), cmd_send: None, handle: None, state }
    }
    /// Schedule a re-start of the cargo check worker.
@@ -87,84 +82,13 @@ impl std::ops::Drop for CheckWatcher {
    }
 }
-#[derive(Clone, Debug)]
-pub struct CheckState {
-    diagnostic_collection: HashMap<Url, Vec<Diagnostic>>,
-    suggested_fix_collection: HashMap<Url, Vec<SuggestedFix>>,
-}
-impl CheckState {
-    fn new() -> CheckState {
-        CheckState {
-            diagnostic_collection: HashMap::new(),
-            suggested_fix_collection: HashMap::new(),
-        }
-    }
-    /// Clear the cached diagnostics, and schedule updating diagnostics by the
-    /// server, to clear stale results.
-    pub fn clear(&mut self) -> Vec<Url> {
-        let cleared_files: Vec<Url> = self.diagnostic_collection.keys().cloned().collect();
-        self.diagnostic_collection.clear();
-        self.suggested_fix_collection.clear();
-        cleared_files
-    }
-    pub fn diagnostics_for(&self, uri: &Url) -> Option<&[Diagnostic]> {
-        self.diagnostic_collection.get(uri).map(|d| d.as_slice())
-    }
-    pub fn fixes_for(&self, uri: &Url) -> Option<&[SuggestedFix]> {
-        self.suggested_fix_collection.get(uri).map(|d| d.as_slice())
-    }
-    pub fn add_diagnostic_with_fixes(&mut self, file_uri: Url, diagnostic: DiagnosticWithFixes) {
-        for fix in diagnostic.suggested_fixes {
-            self.add_suggested_fix_for_diagnostic(fix, &diagnostic.diagnostic);
-        }
-        self.add_diagnostic(file_uri, diagnostic.diagnostic);
-    }
-    fn add_diagnostic(&mut self, file_uri: Url, diagnostic: Diagnostic) {
-        let diagnostics = self.diagnostic_collection.entry(file_uri).or_default();
-        // If we're building multiple targets it's possible we've already seen this diagnostic
-        let is_duplicate = diagnostics.iter().any(|d| are_diagnostics_equal(d, &diagnostic));
-        if is_duplicate {
-            return;
-        }
-        diagnostics.push(diagnostic);
-    }
-    fn add_suggested_fix_for_diagnostic(
-        &mut self,
-        mut suggested_fix: SuggestedFix,
-        diagnostic: &Diagnostic,
-    ) {
-        let file_uri = suggested_fix.location.uri.clone();
-        let file_suggestions = self.suggested_fix_collection.entry(file_uri).or_default();
-        let existing_suggestion: Option<&mut SuggestedFix> =
-            file_suggestions.iter_mut().find(|s| s == &&suggested_fix);
-        if let Some(existing_suggestion) = existing_suggestion {
-            // The existing suggestion also applies to this new diagnostic
-            existing_suggestion.diagnostics.push(diagnostic.clone());
-        } else {
-            // We haven't seen this suggestion before
-            suggested_fix.diagnostics.push(diagnostic.clone());
-            file_suggestions.push(suggested_fix);
-        }
-    }
-}
 #[derive(Debug)]
 pub enum CheckTask {
    /// Request a clearing of all cached diagnostics from the check watcher
    ClearDiagnostics,
    /// Request adding a diagnostic with fixes included to a file
-    AddDiagnostic(Url, DiagnosticWithFixes),
+    AddDiagnostic { url: Url, diagnostic: Diagnostic, fixes: Vec<CodeActionOrCommand> },
    /// Request check progress notification to client
    Status(WorkDoneProgress),
@@ -279,10 +203,17 @@ impl CheckWatcherThread {
                        None => return,
                    };
-                let MappedRustDiagnostic { location, diagnostic, suggested_fixes } = map_result;
+                let MappedRustDiagnostic { location, diagnostic, fixes } = map_result;
+                let fixes = fixes
+                    .into_iter()
+                    .map(|fix| {
+                        CodeAction { diagnostics: Some(vec![diagnostic.clone()]), ..fix }.into()
+                    })
+                    .collect();
-                let diagnostic = DiagnosticWithFixes { diagnostic, suggested_fixes };
+                task_send
-                task_send.send(CheckTask::AddDiagnostic(location.uri, diagnostic)).unwrap();
+                    .send(CheckTask::AddDiagnostic { url: location.uri, diagnostic, fixes })
+                    .unwrap();
            }
            CheckEvent::Msg(Message::BuildScriptExecuted(_msg)) => {}
@@ -294,7 +225,7 @@ impl CheckWatcherThread {
 #[derive(Debug)]
 pub struct DiagnosticWithFixes {
    diagnostic: Diagnostic,
-    suggested_fixes: Vec<SuggestedFix>,
+    fixes: Vec<CodeAction>,
 }
 /// WatchThread exists to wrap around the communication needed to be able to
@@ -429,10 +360,3 @@ impl std::ops::Drop for WatchThread {
        }
    }
 }
-fn are_diagnostics_equal(left: &Diagnostic, right: &Diagnostic) -> bool {
-    left.source == right.source
-        && left.severity == right.severity
-        && left.range == right.range
-        && left.message == right.message
-}
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index 7499dff31..6352c71ef 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -22,7 +22,7 @@ use crate::{
        diagnostics::DefDiagnostic, mod_resolution::ModDir, path_resolution::ReachedFixedPoint,
        raw, BuiltinShadowMode, CrateDefMap, ModuleData, ModuleOrigin, ResolveMode,
    },
-    path::{ModPath, PathKind},
+    path::{ImportAlias, ModPath, PathKind},
    per_ns::PerNs,
    visibility::Visibility,
    AdtId, AstId, ConstLoc, ContainerId, EnumLoc, EnumVariantId, FunctionLoc, ImplLoc, Intern,
@@ -438,7 +438,11 @@ where
        } else {
            match import.path.segments.last() {
                Some(last_segment) => {
-                    let name = import.alias.clone().unwrap_or_else(|| last_segment.clone());
+                    let name = match &import.alias {
+                        Some(ImportAlias::Alias(name)) => name.clone(),
+                        Some(ImportAlias::Underscore) => last_segment.clone(), // FIXME rust-analyzer#2736
+                        None => last_segment.clone(),
+                    };
                    log::debug!("resolved import {:?} ({:?}) to {:?}", name, import, def);
                    // extern crates in the crate root are special-cased to insert entries into the extern prelude: rust-lang/rust#54658
diff --git a/crates/ra_hir_def/src/nameres/raw.rs b/crates/ra_hir_def/src/nameres/raw.rs
index fac1169ef..650cf1f98 100644
--- a/crates/ra_hir_def/src/nameres/raw.rs
+++ b/crates/ra_hir_def/src/nameres/raw.rs
@@ -22,8 +22,11 @@ use ra_syntax::{
 use test_utils::tested_by;
 use crate::{
-    attr::Attrs, db::DefDatabase, path::ModPath, visibility::RawVisibility, FileAstId, HirFileId,
+    attr::Attrs,
-    InFile,
+    db::DefDatabase,
+    path::{ImportAlias, ModPath},
+    visibility::RawVisibility,
+    FileAstId, HirFileId, InFile,
 };
 /// `RawItems` is a set of top-level items in a file (except for impls).
@@ -145,7 +148,7 @@ impl_arena_id!(Import);
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ImportData {
    pub(super) path: ModPath,
-    pub(super) alias: Option<Name>,
+    pub(super) alias: Option<ImportAlias>,
    pub(super) is_glob: bool,
    pub(super) is_prelude: bool,
    pub(super) is_extern_crate: bool,
@@ -353,7 +356,11 @@ impl RawItemsCollector {
            let path = ModPath::from_name_ref(&name_ref);
            let visibility =
                RawVisibility::from_ast_with_hygiene(extern_crate.visibility(), &self.hygiene);
-            let alias = extern_crate.alias().and_then(|a| a.name()).map(|it| it.as_name());
+            let alias = extern_crate.alias().map(|a| {
+                a.name()
+                    .map(|it| it.as_name())
+                    .map_or(ImportAlias::Underscore, |a| ImportAlias::Alias(a))
+            });
            let attrs = self.parse_attrs(&extern_crate);
            // FIXME: cfg_attr
            let is_macro_use = extern_crate.has_atom_attr("macro_use");
diff --git a/crates/ra_hir_def/src/path.rs b/crates/ra_hir_def/src/path.rs
index a150b899f..246032c13 100644
--- a/crates/ra_hir_def/src/path.rs
+++ b/crates/ra_hir_def/src/path.rs
@@ -34,6 +34,14 @@ pub enum PathKind {
    DollarCrate(CrateId),
 }
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ImportAlias {
+    /// Unnamed alias, as in `use Foo as _;`
+    Underscore,
+    /// Named alias
+    Alias(Name),
+}
 impl ModPath {
    pub fn from_src(path: ast::Path, hygiene: &Hygiene) -> Option<ModPath> {
        lower::lower_path(path, hygiene).map(|it| it.mod_path)
@@ -57,7 +65,7 @@ impl ModPath {
    pub(crate) fn expand_use_item(
        item_src: InFile<ast::UseItem>,
        hygiene: &Hygiene,
-        mut cb: impl FnMut(ModPath, &ast::UseTree, /* is_glob */ bool, Option<Name>),
+        mut cb: impl FnMut(ModPath, &ast::UseTree, /* is_glob */ bool, Option<ImportAlias>),
    ) {
        if let Some(tree) = item_src.value.use_tree() {
            lower::lower_use_tree(None, tree, hygiene, &mut cb);
diff --git a/crates/ra_hir_def/src/path/lower/lower_use.rs b/crates/ra_hir_def/src/path/lower/lower_use.rs
index 531878174..d2bc9d193 100644
--- a/crates/ra_hir_def/src/path/lower/lower_use.rs
+++ b/crates/ra_hir_def/src/path/lower/lower_use.rs
@@ -4,20 +4,17 @@
 use std::iter;
 use either::Either;
-use hir_expand::{
+use hir_expand::{hygiene::Hygiene, name::AsName};
-    hygiene::Hygiene,
-    name::{AsName, Name},
-};
 use ra_syntax::ast::{self, NameOwner};
 use test_utils::tested_by;
-use crate::path::{ModPath, PathKind};
+use crate::path::{ImportAlias, ModPath, PathKind};
 pub(crate) fn lower_use_tree(
    prefix: Option<ModPath>,
    tree: ast::UseTree,
    hygiene: &Hygiene,
-    cb: &mut dyn FnMut(ModPath, &ast::UseTree, bool, Option<Name>),
+    cb: &mut dyn FnMut(ModPath, &ast::UseTree, bool, Option<ImportAlias>),
 ) {
    if let Some(use_tree_list) = tree.use_tree_list() {
        let prefix = match tree.path() {
@@ -34,7 +31,11 @@ pub(crate) fn lower_use_tree(
            lower_use_tree(prefix.clone(), child_tree, hygiene, cb);
        }
    } else {
-        let alias = tree.alias().and_then(|a| a.name()).map(|a| a.as_name());
+        let alias = tree.alias().map(|a| {
+            a.name()
+                .map(|it| it.as_name())
+                .map_or(ImportAlias::Underscore, |a| ImportAlias::Alias(a))
+        });
        let is_glob = tree.has_star();
        if let Some(ast_path) = tree.path() {
            // Handle self in a path.
diff --git a/crates/ra_ide/src/imports_locator.rs b/crates/ra_ide/src/imports_locator.rs
index 48b014c7d..9e1a1c1ec 100644
--- a/crates/ra_ide/src/imports_locator.rs
+++ b/crates/ra_ide/src/imports_locator.rs
@@ -64,12 +64,9 @@ impl ImportsLocator for ImportsLocatorIde<'_> {
            .into_iter()
            .chain(lib_results.into_iter())
            .filter_map(|import_candidate| self.get_name_definition(db, &import_candidate))
-            .filter_map(|name_definition_to_import| {
+            .filter_map(|name_definition_to_import| match name_definition_to_import.kind {
-                if let NameKind::Def(module_def) = name_definition_to_import.kind {
+                NameKind::Def(module_def) => Some(module_def),
-                    Some(module_def)
+                _ => None,
-                } else {
-                    None
-                }
            })
            .collect()
    }
diff --git a/crates/ra_ide/src/inlay_hints.rs b/crates/ra_ide/src/inlay_hints.rs
index 393ca9447..de447a5aa 100644
--- a/crates/ra_ide/src/inlay_hints.rs
+++ b/crates/ra_ide/src/inlay_hints.rs
@@ -376,7 +376,7 @@ fn main() {
    let mut start = 0;
    (0..2).for_each(|increment| {
        start += increment;
-    })
+    });
    let multiply = |a, b, c, d| a * b * c * d;
    let _: i32 = multiply(1, 2, 3, 4);
@@ -399,37 +399,37 @@ fn main() {
                label: "i32",
            },
            InlayHint {
-                range: [114; 122),
+                range: [115; 123),
                kind: TypeHint,
                label: "|…| -> i32",
            },
            InlayHint {
-                range: [126; 127),
+                range: [127; 128),
                kind: TypeHint,
                label: "i32",
            },
            InlayHint {
-                range: [129; 130),
+                range: [130; 131),
                kind: TypeHint,
                label: "i32",
            },
            InlayHint {
-                range: [132; 133),
+                range: [133; 134),
                kind: TypeHint,
                label: "i32",
            },
            InlayHint {
-                range: [135; 136),
+                range: [136; 137),
                kind: TypeHint,
                label: "i32",
            },
            InlayHint {
-                range: [200; 212),
+                range: [201; 213),
                kind: TypeHint,
                label: "&|…| -> i32",
            },
            InlayHint {
-                range: [235; 244),
+                range: [236; 245),
                kind: TypeHint,
                label: "|| -> i32",
            },
diff --git a/crates/ra_ide/src/references/rename.rs b/crates/ra_ide/src/references/rename.rs
index 626efb603..9a84c1c88 100644
--- a/crates/ra_ide/src/references/rename.rs
+++ b/crates/ra_ide/src/references/rename.rs
@@ -2,7 +2,9 @@
 use hir::ModuleSource;
 use ra_db::{RelativePath, RelativePathBuf, SourceDatabase, SourceDatabaseExt};
-use ra_syntax::{algo::find_node_at_offset, ast, tokenize, AstNode, SyntaxKind, SyntaxNode};
+use ra_syntax::{
+    algo::find_node_at_offset, ast, lex_single_valid_syntax_kind, AstNode, SyntaxKind, SyntaxNode,
+};
 use ra_text_edit::TextEdit;
 use crate::{
@@ -17,11 +19,9 @@ pub(crate) fn rename(
    position: FilePosition,
    new_name: &str,
 ) -> Option<RangeInfo<SourceChange>> {
-    let tokens = tokenize(new_name);
+    match lex_single_valid_syntax_kind(new_name)? {
-    if tokens.len() != 1
+        SyntaxKind::IDENT | SyntaxKind::UNDERSCORE => (),
-        || (tokens[0].kind != SyntaxKind::IDENT && tokens[0].kind != SyntaxKind::UNDERSCORE)
+        _ => return None,
-    {
-        return None;
    }
    let parse = db.parse(position.file_id);
diff --git a/crates/ra_lsp_server/src/diagnostics.rs b/crates/ra_lsp_server/src/diagnostics.rs
new file mode 100644
index 000000000..ea08bce24
--- /dev/null
+++ b/crates/ra_lsp_server/src/diagnostics.rs
@@ -0,0 +1,85 @@
+//! Book keeping for keeping diagnostics easily in sync with the client.
+use lsp_types::{CodeActionOrCommand, Diagnostic, Range};
+use ra_ide::FileId;
+use std::{collections::HashMap, sync::Arc};
+pub type CheckFixes = Arc<HashMap<FileId, Vec<Fix>>>;
+#[derive(Debug, Default, Clone)]
+pub struct DiagnosticCollection {
+    pub native: HashMap<FileId, Vec<Diagnostic>>,
+    pub check: HashMap<FileId, Vec<Diagnostic>>,
+    pub check_fixes: CheckFixes,
+}
+#[derive(Debug, Clone)]
+pub struct Fix {
+    pub range: Range,
+    pub action: CodeActionOrCommand,
+}
+#[derive(Debug)]
+pub enum DiagnosticTask {
+    ClearCheck,
+    AddCheck(FileId, Diagnostic, Vec<CodeActionOrCommand>),
+    SetNative(FileId, Vec<Diagnostic>),
+}
+impl DiagnosticCollection {
+    pub fn clear_check(&mut self) -> Vec<FileId> {
+        Arc::make_mut(&mut self.check_fixes).clear();
+        self.check.drain().map(|(key, _value)| key).collect()
+    }
+    pub fn add_check_diagnostic(
+        &mut self,
+        file_id: FileId,
+        diagnostic: Diagnostic,
+        fixes: Vec<CodeActionOrCommand>,
+    ) {
+        let diagnostics = self.check.entry(file_id).or_default();
+        for existing_diagnostic in diagnostics.iter() {
+            if are_diagnostics_equal(&existing_diagnostic, &diagnostic) {
+                return;
+            }
+        }
+        let check_fixes = Arc::make_mut(&mut self.check_fixes);
+        check_fixes
+            .entry(file_id)
+            .or_default()
+            .extend(fixes.into_iter().map(|action| Fix { range: diagnostic.range, action }));
+        diagnostics.push(diagnostic);
+    }
+    pub fn set_native_diagnostics(&mut self, file_id: FileId, diagnostics: Vec<Diagnostic>) {
+        self.native.insert(file_id, diagnostics);
+    }
+    pub fn diagnostics_for(&self, file_id: FileId) -> impl Iterator<Item = &Diagnostic> {
+        let native = self.native.get(&file_id).into_iter().flatten();
+        let check = self.check.get(&file_id).into_iter().flatten();
+        native.chain(check)
+    }
+    pub fn handle_task(&mut self, task: DiagnosticTask) -> Vec<FileId> {
+        match task {
+            DiagnosticTask::ClearCheck => self.clear_check(),
+            DiagnosticTask::AddCheck(file_id, diagnostic, fixes) => {
+                self.add_check_diagnostic(file_id, diagnostic, fixes);
+                vec![file_id]
+            }
+            DiagnosticTask::SetNative(file_id, diagnostics) => {
+                self.set_native_diagnostics(file_id, diagnostics);
+                vec![file_id]
+            }
+        }
+    }
+}
+fn are_diagnostics_equal(left: &Diagnostic, right: &Diagnostic) -> bool {
+    left.source == right.source
+        && left.severity == right.severity
+        && left.range == right.range
+        && left.message == right.message
+}
diff --git a/crates/ra_lsp_server/src/lib.rs b/crates/ra_lsp_server/src/lib.rs
index 2ca149fd5..1208c1343 100644
--- a/crates/ra_lsp_server/src/lib.rs
+++ b/crates/ra_lsp_server/src/lib.rs
@@ -29,6 +29,7 @@ mod markdown;
 pub mod req;
 mod config;
 mod world;
+mod diagnostics;
 pub type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;
 pub use crate::{
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index 508fe08c0..12961ba37 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -17,16 +17,17 @@ use std::{
 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::{CheckOptions, CheckTask};
+use ra_cargo_watch::{url_from_path_with_drive_lowercasing, CheckOptions, CheckTask};
 use ra_ide::{Canceled, FeatureFlags, FileId, LibraryData, SourceRootId};
 use ra_prof::profile;
-use ra_vfs::{VfsTask, Watch};
+use ra_vfs::{VfsFile, VfsTask, Watch};
 use relative_path::RelativePathBuf;
 use rustc_hash::FxHashSet;
 use serde::{de::DeserializeOwned, Serialize};
 use threadpool::ThreadPool;
 use crate::{
+    diagnostics::DiagnosticTask,
    main_loop::{
        pending_requests::{PendingRequest, PendingRequests},
        subscriptions::Subscriptions,
@@ -254,6 +255,7 @@ pub fn main_loop(
 enum Task {
    Respond(Response),
    Notify(Notification),
+    Diagnostic(DiagnosticTask),
 }
 enum Event {
@@ -359,7 +361,7 @@ fn loop_turn(
            world_state.maybe_collect_garbage();
            loop_state.in_flight_libraries -= 1;
        }
-        Event::CheckWatcher(task) => on_check_task(pool, task, world_state, task_sender)?,
+        Event::CheckWatcher(task) => on_check_task(task, world_state, task_sender)?,
        Event::Msg(msg) => match msg {
            Message::Request(req) => on_request(
                world_state,
@@ -464,6 +466,7 @@ fn on_task(
        Task::Notify(n) => {
            msg_sender.send(n.into()).unwrap();
        }
+        Task::Diagnostic(task) => on_diagnostic_task(task, msg_sender, state),
    }
 }
@@ -621,23 +624,26 @@ fn on_notification(
 }
 fn on_check_task(
-    pool: &ThreadPool,
    task: CheckTask,
    world_state: &mut WorldState,
    task_sender: &Sender<Task>,
 ) -> Result<()> {
-    let urls = match task {
+    match task {
        CheckTask::ClearDiagnostics => {
-            let state = Arc::get_mut(&mut world_state.check_watcher.state)
+            task_sender.send(Task::Diagnostic(DiagnosticTask::ClearCheck))?;
-                .expect("couldn't get check watcher state as mutable");
-            state.clear()
        }
-        CheckTask::AddDiagnostic(url, diagnostic) => {
+        CheckTask::AddDiagnostic { url, diagnostic, fixes } => {
-            let state = Arc::get_mut(&mut world_state.check_watcher.state)
+            let path = url.to_file_path().map_err(|()| format!("invalid uri: {}", url))?;
-                .expect("couldn't get check watcher state as mutable");
+            let file_id = world_state
-            state.add_diagnostic_with_fixes(url.clone(), diagnostic);
+                .vfs
-            vec![url]
+                .read()
+                .path2file(&path)
+                .map(|it| FileId(it.0))
+                .ok_or_else(|| format!("unknown file: {}", path.to_string_lossy()))?;
+            task_sender
+                .send(Task::Diagnostic(DiagnosticTask::AddCheck(file_id, diagnostic, fixes)))?;
        }
        CheckTask::Status(progress) => {
@@ -647,31 +653,30 @@ fn on_check_task(
            };
            let not = notification_new::<req::Progress>(params);
            task_sender.send(Task::Notify(not)).unwrap();
-            Vec::new()
        }
    };
-    let subscriptions = urls
+    Ok(())
-        .into_iter()
+}
-        .map(|url| {
-            let path = url.to_file_path().map_err(|()| format!("invalid uri: {}", url))?;
-            Ok(world_state.vfs.read().path2file(&path).map(|it| FileId(it.0)))
-        })
-        .filter_map(|res| res.transpose())
-        .collect::<Result<Vec<_>>>()?;
-    // We manually send a diagnostic update when the watcher asks
+fn on_diagnostic_task(task: DiagnosticTask, msg_sender: &Sender<Message>, state: &mut WorldState) {
-    // us to, to avoid the issue of having to change the file to
+    let subscriptions = state.diagnostics.handle_task(task);
-    // receive updated diagnostics.
-    update_file_notifications_on_threadpool(
-        pool,
-        world_state.snapshot(),
-        false,
-        task_sender.clone(),
-        subscriptions,
-    );
-    Ok(())
+    for file_id in subscriptions {
+        let path = state.vfs.read().file2path(VfsFile(file_id.0));
+        let uri = match url_from_path_with_drive_lowercasing(&path) {
+            Ok(uri) => uri,
+            Err(err) => {
+                log::error!("Couldn't convert path to url ({}): {:?}", err, path.to_string_lossy());
+                continue;
+            }
+        };
+        let diagnostics = state.diagnostics.diagnostics_for(file_id).cloned().collect();
+        let params = req::PublishDiagnosticsParams { uri, diagnostics, version: None };
+        let not = notification_new::<req::PublishDiagnostics>(params);
+        msg_sender.send(not.into()).unwrap();
+    }
 }
 struct PoolDispatcher<'a> {
@@ -819,9 +824,8 @@ fn update_file_notifications_on_threadpool(
                            log::error!("failed to compute diagnostics: {:?}", e);
                        }
                    }
-                    Ok(params) => {
+                    Ok(task) => {
-                        let not = notification_new::<req::PublishDiagnostics>(params);
+                        task_sender.send(Task::Diagnostic(task)).unwrap();
-                        task_sender.send(Task::Notify(not)).unwrap();
                    }
                }
            }
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index 9aa1e7eea..282f6e8fc 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -33,6 +33,7 @@ use crate::{
        to_call_hierarchy_item, to_location, Conv, ConvWith, FoldConvCtx, MapConvWith, TryConvWith,
        TryConvWithToVec,
    },
+    diagnostics::DiagnosticTask,
    req::{self, Decoration, InlayHint, InlayHintsParams, InlayKind},
    world::WorldSnapshot,
    LspError, Result,
@@ -676,28 +677,12 @@ pub fn handle_code_action(
        res.push(action.into());
    }
-    for fix in world.check_watcher.fixes_for(&params.text_document.uri).into_iter().flatten() {
+    for fix in world.check_fixes.get(&file_id).into_iter().flatten() {
-        let fix_range = fix.location.range.conv_with(&line_index);
+        let fix_range = fix.range.conv_with(&line_index);
        if fix_range.intersection(&range).is_none() {
            continue;
        }
+        res.push(fix.action.clone());
-        let edit = {
-            let edits = vec![TextEdit::new(fix.location.range, fix.replacement.clone())];
-            let mut edit_map = std::collections::HashMap::new();
-            edit_map.insert(fix.location.uri.clone(), edits);
-            WorkspaceEdit::new(edit_map)
-        };
-        let action = CodeAction {
-            title: fix.title.clone(),
-            kind: Some("quickfix".to_string()),
-            diagnostics: Some(fix.diagnostics.clone()),
-            edit: Some(edit),
-            command: None,
-            is_preferred: None,
-        };
-        res.push(action.into());
    }
    for assist in world.analysis().assists(FileRange { file_id, range })?.into_iter() {
@@ -875,14 +860,10 @@ pub fn handle_document_highlight(
    ))
 }
-pub fn publish_diagnostics(
+pub fn publish_diagnostics(world: &WorldSnapshot, file_id: FileId) -> Result<DiagnosticTask> {
-    world: &WorldSnapshot,
-    file_id: FileId,
-) -> Result<req::PublishDiagnosticsParams> {
    let _p = profile("publish_diagnostics");
-    let uri = world.file_id_to_uri(file_id)?;
    let line_index = world.analysis().file_line_index(file_id)?;
-    let mut diagnostics: Vec<Diagnostic> = world
+    let diagnostics: Vec<Diagnostic> = world
        .analysis()
        .diagnostics(file_id)?
        .into_iter()
@@ -896,10 +877,7 @@ pub fn publish_diagnostics(
            tags: None,
        })
        .collect();
-    if let Some(check_diags) = world.check_watcher.diagnostics_for(&uri) {
+    Ok(DiagnosticTask::SetNative(file_id, diagnostics))
-        diagnostics.extend(check_diags.iter().cloned());
-    }
-    Ok(req::PublishDiagnosticsParams { uri, diagnostics, version: None })
 }
 pub fn publish_decorations(
diff --git a/crates/ra_lsp_server/src/world.rs b/crates/ra_lsp_server/src/world.rs
index 3059ef9ec..1ee02b47c 100644
--- a/crates/ra_lsp_server/src/world.rs
+++ b/crates/ra_lsp_server/src/world.rs
@@ -12,9 +12,7 @@ use crossbeam_channel::{unbounded, Receiver};
 use lsp_server::ErrorCode;
 use lsp_types::Url;
 use parking_lot::RwLock;
-use ra_cargo_watch::{
+use ra_cargo_watch::{url_from_path_with_drive_lowercasing, CheckOptions, CheckWatcher};
-    url_from_path_with_drive_lowercasing, CheckOptions, CheckState, CheckWatcher,
-};
 use ra_ide::{
    Analysis, AnalysisChange, AnalysisHost, CrateGraph, FeatureFlags, FileId, LibraryData,
    SourceRootId,
@@ -25,6 +23,7 @@ use ra_vfs_glob::{Glob, RustPackageFilterBuilder};
 use relative_path::RelativePathBuf;
 use crate::{
+    diagnostics::{CheckFixes, DiagnosticCollection},
    main_loop::pending_requests::{CompletedRequest, LatestRequests},
    LspError, Result,
 };
@@ -55,6 +54,7 @@ pub struct WorldState {
    pub task_receiver: Receiver<VfsTask>,
    pub latest_requests: Arc<RwLock<LatestRequests>>,
    pub check_watcher: CheckWatcher,
+    pub diagnostics: DiagnosticCollection,
 }
 /// An immutable snapshot of the world's state at a point in time.
@@ -63,7 +63,7 @@ pub struct WorldSnapshot {
    pub workspaces: Arc<Vec<ProjectWorkspace>>,
    pub analysis: Analysis,
    pub latest_requests: Arc<RwLock<LatestRequests>>,
-    pub check_watcher: CheckState,
+    pub check_fixes: CheckFixes,
    vfs: Arc<RwLock<Vfs>>,
 }
@@ -159,6 +159,7 @@ impl WorldState {
            task_receiver,
            latest_requests: Default::default(),
            check_watcher,
+            diagnostics: Default::default(),
        }
    }
@@ -220,7 +221,7 @@ impl WorldState {
            analysis: self.analysis_host.analysis(),
            vfs: Arc::clone(&self.vfs),
            latest_requests: Arc::clone(&self.latest_requests),
-            check_watcher: (*self.check_watcher.state).clone(),
+            check_fixes: Arc::clone(&self.diagnostics.check_fixes),
        }
    }
diff --git a/crates/ra_mbe/src/subtree_source.rs b/crates/ra_mbe/src/subtree_source.rs
index b841c39d3..c9f42b3dd 100644
--- a/crates/ra_mbe/src/subtree_source.rs
+++ b/crates/ra_mbe/src/subtree_source.rs
@@ -1,7 +1,7 @@
 //! FIXME: write short doc here
 use ra_parser::{Token, TokenSource};
-use ra_syntax::{classify_literal, SmolStr, SyntaxKind, SyntaxKind::*, T};
+use ra_syntax::{lex_single_valid_syntax_kind, SmolStr, SyntaxKind, SyntaxKind::*, T};
 use std::cell::{Cell, Ref, RefCell};
 use tt::buffer::{Cursor, TokenBuffer};
@@ -129,8 +129,9 @@ fn convert_delim(d: Option<tt::DelimiterKind>, closing: bool) -> TtToken {
 }
 fn convert_literal(l: &tt::Literal) -> TtToken {
-    let kind =
+    let kind = lex_single_valid_syntax_kind(&l.text)
-        classify_literal(&l.text).map(|tkn| tkn.kind).unwrap_or_else(|| match l.text.as_ref() {
+        .filter(|kind| kind.is_literal())
+        .unwrap_or_else(|| match l.text.as_ref() {
            "true" => T![true],
            "false" => T![false],
            _ => panic!("Fail to convert given literal {:#?}", &l),
diff --git a/crates/ra_syntax/src/algo.rs b/crates/ra_syntax/src/algo.rs
index 30a479f01..acf677e7d 100644
--- a/crates/ra_syntax/src/algo.rs
+++ b/crates/ra_syntax/src/algo.rs
@@ -81,7 +81,7 @@ impl TreeDiff {
 /// Specifically, returns a map whose keys are descendants of `from` and values
 /// are descendants of `to`, such that  `replace_descendants(from, map) == to`.
 ///
-/// A trivial solution is a singletom map `{ from: to }`, but this function
+/// A trivial solution is a singleton map `{ from: to }`, but this function
 /// tries to find a more fine-grained diff.
 pub fn diff(from: &SyntaxNode, to: &SyntaxNode) -> TreeDiff {
    let mut buf = FxHashMap::default();
diff --git a/crates/ra_syntax/src/ast/make.rs b/crates/ra_syntax/src/ast/make.rs
index 36e648180..38c0e9a66 100644
--- a/crates/ra_syntax/src/ast/make.rs
+++ b/crates/ra_syntax/src/ast/make.rs
@@ -2,7 +2,7 @@
 //! of smaller pieces.
 use itertools::Itertools;
-use crate::{ast, AstNode, SourceFile, SyntaxKind, SyntaxToken};
+use crate::{ast, AstNode, SourceFile, SyntaxKind, SyntaxNode, SyntaxToken};
 pub fn name(text: &str) -> ast::Name {
    ast_from_text(&format!("mod {};", text))
@@ -179,7 +179,16 @@ pub fn token(kind: SyntaxKind) -> SyntaxToken {
 fn ast_from_text<N: AstNode>(text: &str) -> N {
    let parse = SourceFile::parse(text);
-    parse.tree().syntax().descendants().find_map(N::cast).unwrap()
+    let node = parse.tree().syntax().descendants().find_map(N::cast).unwrap();
+    let node = node.syntax().clone();
+    let node = unroot(node);
+    let node = N::cast(node).unwrap();
+    assert_eq!(node.syntax().text_range().start(), 0.into());
+    node
+}
+fn unroot(n: SyntaxNode) -> SyntaxNode {
+    SyntaxNode::new_root(n.green().clone())
 }
 pub mod tokens {
diff --git a/crates/ra_syntax/src/lib.rs b/crates/ra_syntax/src/lib.rs
index 9931fec84..f8f4b64c1 100644
--- a/crates/ra_syntax/src/lib.rs
+++ b/crates/ra_syntax/src/lib.rs
@@ -41,7 +41,9 @@ use crate::syntax_node::GreenNode;
 pub use crate::{
    algo::InsertPosition,
    ast::{AstNode, AstToken},
-    parsing::{classify_literal, tokenize, Token},
+    parsing::{
+        lex_single_syntax_kind, lex_single_valid_syntax_kind, tokenize, Token, TokenizeError,
+    },
    ptr::{AstPtr, SyntaxNodePtr},
    syntax_error::{Location, SyntaxError, SyntaxErrorKind},
    syntax_node::{
diff --git a/crates/ra_syntax/src/parsing.rs b/crates/ra_syntax/src/parsing.rs
index 0387f0378..e5eb80850 100644
--- a/crates/ra_syntax/src/parsing.rs
+++ b/crates/ra_syntax/src/parsing.rs
@@ -7,15 +7,23 @@ mod text_tree_sink;
 mod reparsing;
 use crate::{syntax_node::GreenNode, SyntaxError};
+use text_token_source::TextTokenSource;
+use text_tree_sink::TextTreeSink;
-pub use self::lexer::{classify_literal, tokenize, Token};
+pub use lexer::*;
 pub(crate) use self::reparsing::incremental_reparse;
 pub(crate) fn parse_text(text: &str) -> (GreenNode, Vec<SyntaxError>) {
-    let tokens = tokenize(&text);
+    let (tokens, lexer_errors) = tokenize(&text);
-    let mut token_source = text_token_source::TextTokenSource::new(text, &tokens);
-    let mut tree_sink = text_tree_sink::TextTreeSink::new(text, &tokens);
+    let mut token_source = TextTokenSource::new(text, &tokens);
+    let mut tree_sink = TextTreeSink::new(text, &tokens);
    ra_parser::parse(&mut token_source, &mut tree_sink);
-    tree_sink.finish()
+    let (tree, mut parser_errors) = tree_sink.finish();
+    parser_errors.extend(lexer_errors);
+    (tree, parser_errors)
 }
diff --git a/crates/ra_syntax/src/parsing/lexer.rs b/crates/ra_syntax/src/parsing/lexer.rs
index 6d839208d..f889e6a1d 100644
--- a/crates/ra_syntax/src/parsing/lexer.rs
+++ b/crates/ra_syntax/src/parsing/lexer.rs
@@ -1,8 +1,10 @@
-//! FIXME: write short doc here
+//! Lexer analyzes raw input string and produces lexemes (tokens).
+//! It is just a bridge to `rustc_lexer`.
 use crate::{
+    SyntaxError, SyntaxErrorKind,
    SyntaxKind::{self, *},
-    TextUnit,
+    TextRange, TextUnit,
 };
 /// A token of Rust source.
@@ -14,91 +16,261 @@ pub struct Token {
    pub len: TextUnit,
 }
-fn match_literal_kind(kind: rustc_lexer::LiteralKind) -> SyntaxKind {
+/// Break a string up into its component tokens.
-    match kind {
+/// Beware that it checks for shebang first and its length contributes to resulting
-        rustc_lexer::LiteralKind::Int { .. } => INT_NUMBER,
+/// tokens offsets.
-        rustc_lexer::LiteralKind::Float { .. } => FLOAT_NUMBER,
+pub fn tokenize(text: &str) -> (Vec<Token>, Vec<SyntaxError>) {
-        rustc_lexer::LiteralKind::Char { .. } => CHAR,
+    // non-empty string is a precondtion of `rustc_lexer::strip_shebang()`.
-        rustc_lexer::LiteralKind::Byte { .. } => BYTE,
+    if text.is_empty() {
-        rustc_lexer::LiteralKind::Str { .. } => STRING,
+        return Default::default();
-        rustc_lexer::LiteralKind::ByteStr { .. } => BYTE_STRING,
+    }
-        rustc_lexer::LiteralKind::RawStr { .. } => RAW_STRING,
-        rustc_lexer::LiteralKind::RawByteStr { .. } => RAW_BYTE_STRING,
+    let mut tokens = Vec::new();
+    let mut errors = Vec::new();
+    let mut offset: usize = rustc_lexer::strip_shebang(text)
+        .map(|shebang_len| {
+            tokens.push(Token { kind: SHEBANG, len: TextUnit::from_usize(shebang_len) });
+            shebang_len
+        })
+        .unwrap_or(0);
+    let text_without_shebang = &text[offset..];
+    for rustc_token in rustc_lexer::tokenize(text_without_shebang) {
+        let token_len = TextUnit::from_usize(rustc_token.len);
+        let token_range = TextRange::offset_len(TextUnit::from_usize(offset), token_len);
+        let (syntax_kind, error) =
+            rustc_token_kind_to_syntax_kind(&rustc_token.kind, &text[token_range]);
+        tokens.push(Token { kind: syntax_kind, len: token_len });
+        if let Some(error) = error {
+            errors.push(SyntaxError::new(SyntaxErrorKind::TokenizeError(error), token_range));
+        }
+        offset += rustc_token.len;
    }
+    (tokens, errors)
+}
+/// Returns `SyntaxKind` and `Option<SyntaxError>` of the first token
+/// encountered at the beginning of the string.
+///
+/// Returns `None` if the string contains zero *or two or more* tokens.
+/// The token is malformed if the returned error is not `None`.
+///
+/// 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())
+        .map(|(token, error)| (token.kind, error))
+}
+/// The same as `lex_single_syntax_kind()` but returns only `SyntaxKind` and
+/// returns `None` if any tokenization error occured.
+///
+/// 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())
+        .map(|(token, _error)| token.kind)
 }
-/// Break a string up into its component tokens
+/// Returns `SyntaxKind` and `Option<SyntaxError>` of the first token
-pub fn tokenize(text: &str) -> Vec<Token> {
+/// encountered at the beginning of the string.
+///
+/// Returns `None` if the string contains zero tokens or if the token was parsed
+/// with an error.
+/// The token is malformed if the returned error is not `None`.
+///
+/// Beware that unescape errors are not checked at tokenization time.
+fn lex_first_token(text: &str) -> Option<(Token, Option<SyntaxError>)> {
+    // non-empty string is a precondtion of `rustc_lexer::first_token()`.
    if text.is_empty() {
-        return vec![];
+        return None;
-    }
-    let mut text = text;
-    let mut acc = Vec::new();
-    if let Some(len) = rustc_lexer::strip_shebang(text) {
-        acc.push(Token { kind: SHEBANG, len: TextUnit::from_usize(len) });
-        text = &text[len..];
    }
-    while !text.is_empty() {
-        let rustc_token = rustc_lexer::first_token(text);
+    let rustc_token = rustc_lexer::first_token(text);
-        let kind = match rustc_token.kind {
+    let (syntax_kind, error) = rustc_token_kind_to_syntax_kind(&rustc_token.kind, text);
-            rustc_lexer::TokenKind::LineComment => COMMENT,
-            rustc_lexer::TokenKind::BlockComment { .. } => COMMENT,
+    let token = Token { kind: syntax_kind, len: TextUnit::from_usize(rustc_token.len) };
-            rustc_lexer::TokenKind::Whitespace => WHITESPACE,
+    let error = error.map(|error| {
-            rustc_lexer::TokenKind::Ident => {
+        SyntaxError::new(
-                let token_text = &text[..rustc_token.len];
+            SyntaxErrorKind::TokenizeError(error),
+            TextRange::from_to(TextUnit::from(0), TextUnit::of_str(text)),
+        )
+    });
+    Some((token, error))
+}
+// FIXME: simplify TokenizeError to `SyntaxError(String, TextRange)` as per @matklad advice:
+// https://github.com/rust-analyzer/rust-analyzer/pull/2911/files#r371175067
+/// Describes the values of `SyntaxErrorKind::TokenizeError` enum variant.
+/// It describes all the types of errors that may happen during the tokenization
+/// of Rust source.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum TokenizeError {
+    /// Base prefix was provided, but there were no digits
+    /// after it, e.g. `0x`, `0b`.
+    EmptyInt,
+    /// Float exponent lacks digits e.g. `12.34e+`, `12.3E+`, `12e-`, `1_E-`,
+    EmptyExponent,
+    /// Block comment lacks trailing delimiter `*/`
+    UnterminatedBlockComment,
+    /// Character literal lacks trailing delimiter `'`
+    UnterminatedChar,
+    /// Characterish byte literal lacks trailing delimiter `'`
+    UnterminatedByte,
+    /// String literal lacks trailing delimiter `"`
+    UnterminatedString,
+    /// Byte string literal lacks trailing delimiter `"`
+    UnterminatedByteString,
+    /// Raw literal lacks trailing delimiter e.g. `"##`
+    UnterminatedRawString,
+    /// Raw byte string literal lacks trailing delimiter e.g. `"##`
+    UnterminatedRawByteString,
+    /// Raw string lacks a quote after the pound characters e.g. `r###`
+    UnstartedRawString,
+    /// Raw byte string lacks a quote after the pound characters e.g. `br###`
+    UnstartedRawByteString,
+    /// Lifetime starts with a number e.g. `'4ever`
+    LifetimeStartsWithNumber,
+}
+fn rustc_token_kind_to_syntax_kind(
+    rustc_token_kind: &rustc_lexer::TokenKind,
+    token_text: &str,
+) -> (SyntaxKind, Option<TokenizeError>) {
+    // A note on an intended tradeoff:
+    // We drop some useful infromation here (see patterns with double dots `..`)
+    // Storing that info in `SyntaxKind` is not possible due to its layout requirements of
+    // being `u16` that come from `rowan::SyntaxKind`.
+    let syntax_kind = {
+        use rustc_lexer::TokenKind as TK;
+        use TokenizeError as TE;
+        match rustc_token_kind {
+            TK::LineComment => COMMENT,
+            TK::BlockComment { terminated: true } => COMMENT,
+            TK::BlockComment { terminated: false } => {
+                return (COMMENT, Some(TE::UnterminatedBlockComment));
+            }
+            TK::Whitespace => WHITESPACE,
+            TK::Ident => {
                if token_text == "_" {
                    UNDERSCORE
                } else {
-                    SyntaxKind::from_keyword(&text[..rustc_token.len]).unwrap_or(IDENT)
+                    SyntaxKind::from_keyword(token_text).unwrap_or(IDENT)
                }
            }
-            rustc_lexer::TokenKind::RawIdent => IDENT,
-            rustc_lexer::TokenKind::Literal { kind, .. } => match_literal_kind(kind),
+            TK::RawIdent => IDENT,
-            rustc_lexer::TokenKind::Lifetime { .. } => LIFETIME,
+            TK::Literal { kind, .. } => return match_literal_kind(&kind),
-            rustc_lexer::TokenKind::Semi => SEMI,
-            rustc_lexer::TokenKind::Comma => COMMA,
+            TK::Lifetime { starts_with_number: false } => LIFETIME,
-            rustc_lexer::TokenKind::Dot => DOT,
+            TK::Lifetime { starts_with_number: true } => {
-            rustc_lexer::TokenKind::OpenParen => L_PAREN,
+                return (LIFETIME, Some(TE::LifetimeStartsWithNumber))
-            rustc_lexer::TokenKind::CloseParen => R_PAREN,
+            }
-            rustc_lexer::TokenKind::OpenBrace => L_CURLY,
-            rustc_lexer::TokenKind::CloseBrace => R_CURLY,
+            TK::Semi => SEMI,
-            rustc_lexer::TokenKind::OpenBracket => L_BRACK,
+            TK::Comma => COMMA,
-            rustc_lexer::TokenKind::CloseBracket => R_BRACK,
+            TK::Dot => DOT,
-            rustc_lexer::TokenKind::At => AT,
+            TK::OpenParen => L_PAREN,
-            rustc_lexer::TokenKind::Pound => POUND,
+            TK::CloseParen => R_PAREN,
-            rustc_lexer::TokenKind::Tilde => TILDE,
+            TK::OpenBrace => L_CURLY,
-            rustc_lexer::TokenKind::Question => QUESTION,
+            TK::CloseBrace => R_CURLY,
-            rustc_lexer::TokenKind::Colon => COLON,
+            TK::OpenBracket => L_BRACK,
-            rustc_lexer::TokenKind::Dollar => DOLLAR,
+            TK::CloseBracket => R_BRACK,
-            rustc_lexer::TokenKind::Eq => EQ,
+            TK::At => AT,
-            rustc_lexer::TokenKind::Not => EXCL,
+            TK::Pound => POUND,
-            rustc_lexer::TokenKind::Lt => L_ANGLE,
+            TK::Tilde => TILDE,
-            rustc_lexer::TokenKind::Gt => R_ANGLE,
+            TK::Question => QUESTION,
-            rustc_lexer::TokenKind::Minus => MINUS,
+            TK::Colon => COLON,
-            rustc_lexer::TokenKind::And => AMP,
+            TK::Dollar => DOLLAR,
-            rustc_lexer::TokenKind::Or => PIPE,
+            TK::Eq => EQ,
-            rustc_lexer::TokenKind::Plus => PLUS,
+            TK::Not => EXCL,
-            rustc_lexer::TokenKind::Star => STAR,
+            TK::Lt => L_ANGLE,
-            rustc_lexer::TokenKind::Slash => SLASH,
+            TK::Gt => R_ANGLE,
-            rustc_lexer::TokenKind::Caret => CARET,
+            TK::Minus => MINUS,
-            rustc_lexer::TokenKind::Percent => PERCENT,
+            TK::And => AMP,
-            rustc_lexer::TokenKind::Unknown => ERROR,
+            TK::Or => PIPE,
+            TK::Plus => PLUS,
+            TK::Star => STAR,
+            TK::Slash => SLASH,
+            TK::Caret => CARET,
+            TK::Percent => PERCENT,
+            TK::Unknown => ERROR,
+        }
+    };
+    return (syntax_kind, None);
+    fn match_literal_kind(kind: &rustc_lexer::LiteralKind) -> (SyntaxKind, Option<TokenizeError>) {
+        use rustc_lexer::LiteralKind as LK;
+        use TokenizeError as TE;
+        #[rustfmt::skip]
+        let syntax_kind = match *kind {
+            LK::Int { empty_int: false, .. } => INT_NUMBER,
+            LK::Int { empty_int: true, .. } => {
+                return (INT_NUMBER, Some(TE::EmptyInt))
+            }
+            LK::Float { empty_exponent: false, .. } => FLOAT_NUMBER,
+            LK::Float { empty_exponent: true, .. } => {
+                return (FLOAT_NUMBER, Some(TE::EmptyExponent))
+            }
+            LK::Char { terminated: true } => CHAR,
+            LK::Char { terminated: false } => {
+                return (CHAR, Some(TE::UnterminatedChar))
+            }
+            LK::Byte { terminated: true } => BYTE,
+            LK::Byte { terminated: false } => {
+                return (BYTE, Some(TE::UnterminatedByte))
+            }
+            LK::Str { terminated: true } => STRING,
+            LK::Str { terminated: false } => {
+                return (STRING, Some(TE::UnterminatedString))
+            }
+            LK::ByteStr { terminated: true } => BYTE_STRING,
+            LK::ByteStr { terminated: false } => {
+                return (BYTE_STRING, Some(TE::UnterminatedByteString))
+            }
+            LK::RawStr { started: true, terminated: true, .. } => RAW_STRING,
+            LK::RawStr { started: true, terminated: false, .. } => {
+                return (RAW_STRING, Some(TE::UnterminatedRawString))
+            }
+            LK::RawStr { started: false, .. } => {
+                return (RAW_STRING, Some(TE::UnstartedRawString))
+            }
+            LK::RawByteStr { started: true, terminated: true, .. } => RAW_BYTE_STRING,
+            LK::RawByteStr { started: true, terminated: false, .. } => {
+                return (RAW_BYTE_STRING, Some(TE::UnterminatedRawByteString))
+            }
+            LK::RawByteStr { started: false, .. } => {
+                return (RAW_BYTE_STRING, Some(TE::UnstartedRawByteString))
+            }
        };
-        let token = Token { kind, len: TextUnit::from_usize(rustc_token.len) };
-        acc.push(token);
-        text = &text[rustc_token.len..];
-    }
-    acc
-}
-pub fn classify_literal(text: &str) -> Option<Token> {
+        (syntax_kind, None)
-    let t = rustc_lexer::first_token(text);
-    if t.len != text.len() {
-        return None;
    }
-    let kind = match t.kind {
-        rustc_lexer::TokenKind::Literal { kind, .. } => match_literal_kind(kind),
-        _ => return None,
-    };
-    Some(Token { kind, len: TextUnit::from_usize(t.len) })
 }
diff --git a/crates/ra_syntax/src/parsing/reparsing.rs b/crates/ra_syntax/src/parsing/reparsing.rs
index 06bdda11d..a86da0675 100644
--- a/crates/ra_syntax/src/parsing/reparsing.rs
+++ b/crates/ra_syntax/src/parsing/reparsing.rs
@@ -12,7 +12,7 @@ use ra_text_edit::AtomTextEdit;
 use crate::{
    algo,
    parsing::{
-        lexer::{tokenize, Token},
+        lexer::{lex_single_syntax_kind, tokenize, Token},
        text_token_source::TextTokenSource,
        text_tree_sink::TextTreeSink,
    },
@@ -41,37 +41,42 @@ fn reparse_token<'node>(
    root: &'node SyntaxNode,
    edit: &AtomTextEdit,
 ) -> Option<(GreenNode, TextRange)> {
-    let token = algo::find_covering_element(root, edit.delete).as_token()?.clone();
+    let prev_token = algo::find_covering_element(root, edit.delete).as_token()?.clone();
-    match token.kind() {
+    let prev_token_kind = prev_token.kind();
+    match prev_token_kind {
        WHITESPACE | COMMENT | IDENT | STRING | RAW_STRING => {
-            if token.kind() == WHITESPACE || token.kind() == COMMENT {
+            if prev_token_kind == WHITESPACE || prev_token_kind == COMMENT {
                // removing a new line may extends previous token
-                if token.text().to_string()[edit.delete - token.text_range().start()].contains('\n')
+                let deleted_range = edit.delete - prev_token.text_range().start();
-                {
+                if prev_token.text()[deleted_range].contains('\n') {
                    return None;
                }
            }
-            let text = get_text_after_edit(token.clone().into(), &edit);
+            let mut new_text = get_text_after_edit(prev_token.clone().into(), &edit);
-            let lex_tokens = tokenize(&text);
+            let (new_token_kind, _error) = lex_single_syntax_kind(&new_text)?;
-            let lex_token = match lex_tokens[..] {
-                [lex_token] if lex_token.kind == token.kind() => lex_token,
-                _ => return None,
-            };
-            if lex_token.kind == IDENT && is_contextual_kw(&text) {
+            if new_token_kind != prev_token_kind
+                || (new_token_kind == IDENT && is_contextual_kw(&new_text))
+            {
                return None;
            }
-            if let Some(next_char) = root.text().char_at(token.text_range().end()) {
+            // Check that edited token is not a part of the bigger token.
-                let tokens_with_next_char = tokenize(&format!("{}{}", text, next_char));
+            // E.g. if for source code `bruh"str"` the user removed `ruh`, then
-                if tokens_with_next_char.len() == 1 {
+            // `b` no longer remains an identifier, but becomes a part of byte string literal
+            if let Some(next_char) = root.text().char_at(prev_token.text_range().end()) {
+                new_text.push(next_char);
+                let token_with_next_char = lex_single_syntax_kind(&new_text);
+                if let Some((_kind, _error)) = token_with_next_char {
                    return None;
                }
+                new_text.pop();
            }
-            let new_token = GreenToken::new(rowan::SyntaxKind(token.kind().into()), text.into());
+            let new_token =
-            Some((token.replace_with(new_token), token.text_range()))
+                GreenToken::new(rowan::SyntaxKind(prev_token_kind.into()), new_text.into());
+            Some((prev_token.replace_with(new_token), prev_token.text_range()))
        }
        _ => None,
    }
@@ -83,20 +88,26 @@ fn reparse_block<'node>(
 ) -> Option<(GreenNode, Vec<SyntaxError>, TextRange)> {
    let (node, reparser) = find_reparsable_node(root, edit.delete)?;
    let text = get_text_after_edit(node.clone().into(), &edit);
-    let tokens = tokenize(&text);
+    let (tokens, new_lexer_errors) = tokenize(&text);
    if !is_balanced(&tokens) {
        return None;
    }
    let mut token_source = TextTokenSource::new(&text, &tokens);
    let mut tree_sink = TextTreeSink::new(&text, &tokens);
    reparser.parse(&mut token_source, &mut tree_sink);
-    let (green, new_errors) = tree_sink.finish();
-    Some((node.replace_with(green), new_errors, node.text_range()))
+    let (green, mut new_parser_errors) = tree_sink.finish();
+    new_parser_errors.extend(new_lexer_errors);
+    Some((node.replace_with(green), new_parser_errors, node.text_range()))
 }
 fn get_text_after_edit(element: SyntaxElement, edit: &AtomTextEdit) -> String {
    let edit =
        AtomTextEdit::replace(edit.delete - element.text_range().start(), edit.insert.clone());
    let text = match element {
        NodeOrToken::Token(token) => token.text().to_string(),
        NodeOrToken::Node(node) => node.text().to_string(),
@@ -113,6 +124,7 @@ fn is_contextual_kw(text: &str) -> bool {
 fn find_reparsable_node(node: &SyntaxNode, range: TextRange) -> Option<(SyntaxNode, Reparser)> {
    let node = algo::find_covering_element(node, range);
    let mut ancestors = match node {
        NodeOrToken::Token(it) => it.parent().ancestors(),
        NodeOrToken::Node(it) => it.ancestors(),
@@ -182,7 +194,6 @@ mod tests {
        let fully_reparsed = SourceFile::parse(&after);
        let incrementally_reparsed: Parse<SourceFile> = {
            let f = SourceFile::parse(&before);
-            let edit = AtomTextEdit { delete: range, insert: replace_with.to_string() };
            let (green, new_errors, range) =
                incremental_reparse(f.tree().syntax(), &edit, f.errors.to_vec()).unwrap();
            assert_eq!(range.len(), reparsed_len.into(), "reparsed fragment has wrong length");
diff --git a/crates/ra_syntax/src/parsing/text_tree_sink.rs b/crates/ra_syntax/src/parsing/text_tree_sink.rs
index c36756d6c..dd202601d 100644
--- a/crates/ra_syntax/src/parsing/text_tree_sink.rs
+++ b/crates/ra_syntax/src/parsing/text_tree_sink.rs
@@ -92,8 +92,8 @@ impl<'a> TreeSink for TextTreeSink<'a> {
 }
 impl<'a> TextTreeSink<'a> {
-    pub(super) fn new(text: &'a str, tokens: &'a [Token]) -> TextTreeSink<'a> {
+    pub(super) fn new(text: &'a str, tokens: &'a [Token]) -> Self {
-        TextTreeSink {
+        Self {
            text,
            tokens,
            text_pos: 0.into(),
diff --git a/crates/ra_syntax/src/syntax_error.rs b/crates/ra_syntax/src/syntax_error.rs
index 6c171df8d..7f9d36618 100644
--- a/crates/ra_syntax/src/syntax_error.rs
+++ b/crates/ra_syntax/src/syntax_error.rs
@@ -4,7 +4,7 @@ use std::fmt;
 use ra_parser::ParseError;
-use crate::{validation::EscapeError, TextRange, TextUnit};
+use crate::{validation::EscapeError, TextRange, TextUnit, TokenizeError};
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct SyntaxError {
@@ -12,6 +12,10 @@ pub struct SyntaxError {
    location: Location,
 }
+// FIXME: Location should be just `Location(TextRange)`
+// TextUnit enum member just unnecessarily compicates things,
+// we should'n treat it specially, it just as a `TextRange { start: x, end: x + 1 }`
+// see `location_to_range()` in ra_ide/src/diagnostics
 #[derive(Clone, PartialEq, Eq, Hash)]
 pub enum Location {
    Offset(TextUnit),
@@ -67,6 +71,10 @@ impl SyntaxError {
        self
    }
+    pub fn debug_dump(&self, acc: &mut impl fmt::Write) {
+        writeln!(acc, "error {:?}: {}", self.location(), self.kind()).unwrap();
+    }
 }
 impl fmt::Display for SyntaxError {
@@ -79,6 +87,10 @@ impl fmt::Display for SyntaxError {
 pub enum SyntaxErrorKind {
    ParseError(ParseError),
    EscapeError(EscapeError),
+    TokenizeError(TokenizeError),
+    // FIXME: the obvious pattern of this enum dictates that the following enum variants
+    // should be wrapped into something like `SemmanticError(SemmanticError)`
+    // or `ValidateError(ValidateError)` or `SemmanticValidateError(...)`
    InvalidBlockAttr,
    InvalidMatchInnerAttr,
    InvalidTupleIndexFormat,
@@ -101,6 +113,7 @@ impl fmt::Display for SyntaxErrorKind {
            }
            ParseError(msg) => write!(f, "{}", msg.0),
            EscapeError(err) => write!(f, "{}", err),
+            TokenizeError(err) => write!(f, "{}", err),
            VisibilityNotAllowed => {
                write!(f, "unnecessary visibility qualifier")
            }
@@ -111,6 +124,51 @@ impl fmt::Display for SyntaxErrorKind {
    }
 }
+impl fmt::Display for TokenizeError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        #[rustfmt::skip]
+        let msg = match self {
+            TokenizeError::EmptyInt => {
+                "Missing digits after the integer base prefix"
+            }
+            TokenizeError::EmptyExponent => {
+                "Missing digits after the exponent symbol"
+            }
+            TokenizeError::UnterminatedBlockComment => {
+                "Missing trailing `*/` symbols to terminate the block comment"
+            }
+            TokenizeError::UnterminatedChar => {
+                "Missing trailing `'` symbol to terminate the character literal"
+            }
+            TokenizeError::UnterminatedByte => {
+                "Missing trailing `'` symbol to terminate the byte literal"
+            }
+            TokenizeError::UnterminatedString => {
+                "Missing trailing `\"` symbol to terminate the string literal"
+            }
+            TokenizeError::UnterminatedByteString => {
+                "Missing trailing `\"` symbol to terminate the byte string literal"
+            }
+            TokenizeError::UnterminatedRawString => {
+                "Missing trailing `\"` with `#` symbols to terminate the raw string literal"
+            }
+            TokenizeError::UnterminatedRawByteString => {
+                "Missing trailing `\"` with `#` symbols to terminate the raw byte string literal"
+            }
+            TokenizeError::UnstartedRawString => {
+                "Missing `\"` symbol after `#` symbols to begin the raw string literal"
+            }
+            TokenizeError::UnstartedRawByteString => {
+                "Missing `\"` symbol after `#` symbols to begin the raw byte string literal"
+            }
+            TokenizeError::LifetimeStartsWithNumber => {
+                "Lifetime name cannot start with a number"
+            }
+        };
+        write!(f, "{}", msg)
+    }
+}
 impl fmt::Display for EscapeError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        let msg = match self {
diff --git a/crates/ra_syntax/src/syntax_node.rs b/crates/ra_syntax/src/syntax_node.rs
index b3eb5da63..7c2b18af3 100644
--- a/crates/ra_syntax/src/syntax_node.rs
+++ b/crates/ra_syntax/src/syntax_node.rs
@@ -4,7 +4,7 @@
 //! `SyntaxNode`, and a basic traversal API (parent, children, siblings).
 //!
 //! The *real* implementation is in the (language-agnostic) `rowan` crate, this
-//! modules just wraps its API.
+//! module just wraps its API.
 use ra_parser::ParseError;
 use rowan::{GreenNodeBuilder, Language};
@@ -38,17 +38,12 @@ pub type SyntaxElementChildren = rowan::SyntaxElementChildren<RustLanguage>;
 pub use rowan::{Direction, NodeOrToken};
+#[derive(Default)]
 pub struct SyntaxTreeBuilder {
    errors: Vec<SyntaxError>,
    inner: GreenNodeBuilder<'static>,
 }
-impl Default for SyntaxTreeBuilder {
-    fn default() -> SyntaxTreeBuilder {
-        SyntaxTreeBuilder { errors: Vec::new(), inner: GreenNodeBuilder::new() }
-    }
-}
 impl SyntaxTreeBuilder {
    pub(crate) fn finish_raw(self) -> (GreenNode, Vec<SyntaxError>) {
        let green = self.inner.finish();
diff --git a/crates/ra_syntax/src/tests.rs b/crates/ra_syntax/src/tests.rs
index 458920607..fb22b9e54 100644
--- a/crates/ra_syntax/src/tests.rs
+++ b/crates/ra_syntax/src/tests.rs
@@ -1,18 +1,28 @@
 use std::{
    fmt::Write,
-    path::{Component, PathBuf},
+    path::{Component, Path, PathBuf},
 };
 use test_utils::{collect_tests, dir_tests, project_dir, read_text};
-use crate::{fuzz, SourceFile};
+use crate::{fuzz, tokenize, Location, SourceFile, SyntaxError, TextRange, Token};
 #[test]
 fn lexer_tests() {
-    dir_tests(&test_data_dir(), &["lexer"], |text, _| {
+    // FIXME:
-        let tokens = crate::tokenize(text);
+    // * Add tests for unicode escapes in byte-character and [raw]-byte-string literals
-        dump_tokens(&tokens, text)
+    // * Add tests for unescape errors
-    })
+    dir_tests(&test_data_dir(), &["lexer/ok"], |text, path| {
+        let (tokens, errors) = tokenize(text);
+        assert_errors_are_absent(&errors, path);
+        dump_tokens_and_errors(&tokens, &errors, text)
+    });
+    dir_tests(&test_data_dir(), &["lexer/err"], |text, path| {
+        let (tokens, errors) = tokenize(text);
+        assert_errors_are_present(&errors, path);
+        dump_tokens_and_errors(&tokens, &errors, text)
+    });
 }
 #[test]
@@ -32,18 +42,13 @@ fn parser_tests() {
    dir_tests(&test_data_dir(), &["parser/inline/ok", "parser/ok"], |text, path| {
        let parse = SourceFile::parse(text);
        let errors = parse.errors();
-        assert_eq!(
+        assert_errors_are_absent(&errors, path);
-            errors,
-            &[] as &[crate::SyntaxError],
-            "There should be no errors in the file {:?}",
-            path.display(),
-        );
        parse.debug_dump()
    });
    dir_tests(&test_data_dir(), &["parser/err", "parser/inline/err"], |text, path| {
        let parse = SourceFile::parse(text);
        let errors = parse.errors();
-        assert!(!errors.is_empty(), "There should be errors in the file {:?}", path.display());
+        assert_errors_are_present(&errors, path);
        parse.debug_dump()
    });
 }
@@ -75,7 +80,7 @@ fn self_hosting_parsing() {
        .into_iter()
        .filter_entry(|entry| {
            !entry.path().components().any(|component| {
-                // Get all files which are not in the crates/ra_syntax/tests/data folder
+                // Get all files which are not in the crates/ra_syntax/test_data folder
                component == Component::Normal(OsStr::new("test_data"))
            })
        })
@@ -101,15 +106,47 @@ fn test_data_dir() -> PathBuf {
    project_dir().join("crates/ra_syntax/test_data")
 }
-fn dump_tokens(tokens: &[crate::Token], text: &str) -> String {
+fn assert_errors_are_present(errors: &[SyntaxError], path: &Path) {
+    assert!(!errors.is_empty(), "There should be errors in the file {:?}", path.display());
+}
+fn assert_errors_are_absent(errors: &[SyntaxError], path: &Path) {
+    assert_eq!(
+        errors,
+        &[] as &[SyntaxError],
+        "There should be no errors in the file {:?}",
+        path.display(),
+    );
+}
+fn dump_tokens_and_errors(tokens: &[Token], errors: &[SyntaxError], text: &str) -> String {
    let mut acc = String::new();
    let mut offset = 0;
    for token in tokens {
-        let len: u32 = token.len.into();
+        let token_len = token.len.to_usize();
-        let len = len as usize;
+        let token_text = &text[offset..offset + token_len];
-        let token_text = &text[offset..offset + len];
+        offset += token_len;
-        offset += len;
+        writeln!(acc, "{:?} {} {:?}", token.kind, token_len, token_text).unwrap();
-        write!(acc, "{:?} {} {:?}\n", token.kind, token.len, token_text).unwrap()
+    }
+    for err in errors {
+        let err_range = location_to_range(err.location());
+        writeln!(
+            acc,
+            "> error{:?} token({:?}) msg({})",
+            err.location(),
+            &text[err_range],
+            err.kind()
+        )
+        .unwrap();
+    }
+    return acc;
+    // FIXME: copy-pasted this from `ra_ide/src/diagnostics.rs`
+    // `Location` will be refactored soon in new PR, see todos here:
+    // https://github.com/rust-analyzer/rust-analyzer/issues/223
+    fn location_to_range(location: Location) -> TextRange {
+        match location {
+            Location::Offset(offset) => TextRange::offset_len(offset, 1.into()),
+            Location::Range(range) => range,
+        }
    }
-    acc
 }
diff --git a/crates/ra_syntax/src/validation.rs b/crates/ra_syntax/src/validation.rs
index 445e3b3e4..8a5f0e4b7 100644
--- a/crates/ra_syntax/src/validation.rs
+++ b/crates/ra_syntax/src/validation.rs
@@ -94,6 +94,12 @@ impl From<rustc_lexer::unescape::EscapeError> for SyntaxErrorKind {
 }
 pub(crate) fn validate(root: &SyntaxNode) -> Vec<SyntaxError> {
+    // FIXME:
+    // * Add validation of character literal containing only a single char
+    // * Add validation of `crate` keyword not appearing in the middle of the symbol path
+    // * Add validation of doc comments are being attached to nodes
+    // * Remove validation of unterminated literals (it is already implemented in `tokenize()`)
    let mut errors = Vec::new();
    for node in root.descendants() {
        match_ast! {
diff --git a/crates/ra_syntax/test_data/lexer/0010_comments.rs b/crates/ra_syntax/test_data/lexer/0010_comments.rs
deleted file mode 100644
index 71bdd1f9c..000000000
--- a/crates/ra_syntax/test_data/lexer/0010_comments.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env bash
-// hello
-//! World
diff --git a/crates/ra_syntax/test_data/lexer/0010_comments.txt b/crates/ra_syntax/test_data/lexer/0010_comments.txt
deleted file mode 100644
index 3c997de3f..000000000
--- a/crates/ra_syntax/test_data/lexer/0010_comments.txt
+++ /dev/null
@@ -1,6 +0,0 @@
-SHEBANG 19 "#!/usr/bin/env bash"
-WHITESPACE 1 "\n"
-COMMENT 8 "// hello"
-WHITESPACE 1 "\n"
-COMMENT 9 "//! World"
-WHITESPACE 1 "\n"
diff --git a/crates/ra_syntax/test_data/lexer/0014_unclosed_char.rs b/crates/ra_syntax/test_data/lexer/0014_unclosed_char.rs
deleted file mode 100644
index 9c0007077..000000000
--- a/crates/ra_syntax/test_data/lexer/0014_unclosed_char.rs
+++ /dev/null
@@ -1 +0,0 @@
-'1
-\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/0014_unclosed_char.txt b/crates/ra_syntax/test_data/lexer/0014_unclosed_char.txt
deleted file mode 100644
index 737a300ee..000000000
--- a/crates/ra_syntax/test_data/lexer/0014_unclosed_char.txt
+++ /dev/null
@@ -1 +0,0 @@
-LIFETIME 2 "\'1"
diff --git a/crates/ra_syntax/test_data/lexer/0015_unclosed_string.rs b/crates/ra_syntax/test_data/lexer/0015_unclosed_string.rs
deleted file mode 100644
index d771a26d4..000000000
--- a/crates/ra_syntax/test_data/lexer/0015_unclosed_string.rs
+++ /dev/null
@@ -1 +0,0 @@
-"hello
diff --git a/crates/ra_syntax/test_data/lexer/0015_unclosed_string.txt b/crates/ra_syntax/test_data/lexer/0015_unclosed_string.txt
deleted file mode 100644
index 728c40b66..000000000
--- a/crates/ra_syntax/test_data/lexer/0015_unclosed_string.txt
+++ /dev/null
@@ -1 +0,0 @@
-STRING 7 "\"hello\n"
diff --git a/crates/ra_syntax/test_data/lexer/err/0001_unclosed_char_at_eof.rs b/crates/ra_syntax/test_data/lexer/err/0001_unclosed_char_at_eof.rs
new file mode 100644
index 000000000..ad2823b48
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0001_unclosed_char_at_eof.rs
@@ -0,0 +1 @@
+'
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0001_unclosed_char_at_eof.txt b/crates/ra_syntax/test_data/lexer/err/0001_unclosed_char_at_eof.txt
new file mode 100644
index 000000000..f24e1fd32
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0001_unclosed_char_at_eof.txt
@@ -0,0 +1,2 @@
+CHAR 1 "\'"
+> error[0; 1) token("\'") msg(Missing trailing `'` symbol to terminate the character literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0002_unclosed_char_with_ferris.rs b/crates/ra_syntax/test_data/lexer/err/0002_unclosed_char_with_ferris.rs
new file mode 100644
index 000000000..e264a4152
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0002_unclosed_char_with_ferris.rs
@@ -0,0 +1 @@
+'🦀
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0002_unclosed_char_with_ferris.txt b/crates/ra_syntax/test_data/lexer/err/0002_unclosed_char_with_ferris.txt
new file mode 100644
index 000000000..bd08cfc44
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0002_unclosed_char_with_ferris.txt
@@ -0,0 +1,2 @@
+CHAR 5 "\'🦀"
+> error[0; 5) token("\'🦀") msg(Missing trailing `'` symbol to terminate the character literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0003_unclosed_char_with_ascii_escape.rs b/crates/ra_syntax/test_data/lexer/err/0003_unclosed_char_with_ascii_escape.rs
new file mode 100644
index 000000000..cf74b4dad
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0003_unclosed_char_with_ascii_escape.rs
@@ -0,0 +1 @@
+'\x7f
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0003_unclosed_char_with_ascii_escape.txt b/crates/ra_syntax/test_data/lexer/err/0003_unclosed_char_with_ascii_escape.txt
new file mode 100644
index 000000000..0ee22912d
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0003_unclosed_char_with_ascii_escape.txt
@@ -0,0 +1,2 @@
+CHAR 5 "\'\\x7f"
+> error[0; 5) token("\'\\x7f") msg(Missing trailing `'` symbol to terminate the character literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0004_unclosed_char_with_unicode_escape.rs b/crates/ra_syntax/test_data/lexer/err/0004_unclosed_char_with_unicode_escape.rs
new file mode 100644
index 000000000..50be91f68
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0004_unclosed_char_with_unicode_escape.rs
@@ -0,0 +1 @@
+'\u{20AA}
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0004_unclosed_char_with_unicode_escape.txt b/crates/ra_syntax/test_data/lexer/err/0004_unclosed_char_with_unicode_escape.txt
new file mode 100644
index 000000000..96fac42ce
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0004_unclosed_char_with_unicode_escape.txt
@@ -0,0 +1,2 @@
+CHAR 9 "\'\\u{20AA}"
+> error[0; 9) token("\'\\u{20AA}") msg(Missing trailing `'` symbol to terminate the character literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0005_unclosed_char_with_space.rs b/crates/ra_syntax/test_data/lexer/err/0005_unclosed_char_with_space.rs
new file mode 100644
index 000000000..309ecfe47
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0005_unclosed_char_with_space.rs
@@ -0,0 +1 @@
+' 
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0005_unclosed_char_with_space.txt b/crates/ra_syntax/test_data/lexer/err/0005_unclosed_char_with_space.txt
new file mode 100644
index 000000000..2059f3f81
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0005_unclosed_char_with_space.txt
@@ -0,0 +1,2 @@
+CHAR 2 "\' "
+> error[0; 2) token("\' ") msg(Missing trailing `'` symbol to terminate the character literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0006_unclosed_char_with_slash.rs b/crates/ra_syntax/test_data/lexer/err/0006_unclosed_char_with_slash.rs
new file mode 100644
index 000000000..6ba258b10
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0006_unclosed_char_with_slash.rs
@@ -0,0 +1 @@
+'\
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0006_unclosed_char_with_slash.txt b/crates/ra_syntax/test_data/lexer/err/0006_unclosed_char_with_slash.txt
new file mode 100644
index 000000000..7dd376e59
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0006_unclosed_char_with_slash.txt
@@ -0,0 +1,2 @@
+CHAR 2 "\'\\"
+> error[0; 2) token("\'\\") msg(Missing trailing `'` symbol to terminate the character literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0007_unclosed_char_with_slash_n.rs b/crates/ra_syntax/test_data/lexer/err/0007_unclosed_char_with_slash_n.rs
new file mode 100644
index 000000000..78bef7e3e
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0007_unclosed_char_with_slash_n.rs
@@ -0,0 +1 @@
+'\n
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0007_unclosed_char_with_slash_n.txt b/crates/ra_syntax/test_data/lexer/err/0007_unclosed_char_with_slash_n.txt
new file mode 100644
index 000000000..ef7a0a147
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0007_unclosed_char_with_slash_n.txt
@@ -0,0 +1,2 @@
+CHAR 3 "\'\\n"
+> error[0; 3) token("\'\\n") msg(Missing trailing `'` symbol to terminate the character literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0008_unclosed_char_with_slash_single_quote.rs b/crates/ra_syntax/test_data/lexer/err/0008_unclosed_char_with_slash_single_quote.rs
new file mode 100644
index 000000000..a0e722065
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0008_unclosed_char_with_slash_single_quote.rs
@@ -0,0 +1 @@
+'\'
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0008_unclosed_char_with_slash_single_quote.txt b/crates/ra_syntax/test_data/lexer/err/0008_unclosed_char_with_slash_single_quote.txt
new file mode 100644
index 000000000..13fc5ea9a
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0008_unclosed_char_with_slash_single_quote.txt
@@ -0,0 +1,2 @@
+CHAR 3 "\'\\\'"
+> error[0; 3) token("\'\\\'") msg(Missing trailing `'` symbol to terminate the character literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0009_unclosed_byte_at_eof.rs b/crates/ra_syntax/test_data/lexer/err/0009_unclosed_byte_at_eof.rs
new file mode 100644
index 000000000..795dc7e25
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0009_unclosed_byte_at_eof.rs
@@ -0,0 +1 @@
+b'
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0009_unclosed_byte_at_eof.txt b/crates/ra_syntax/test_data/lexer/err/0009_unclosed_byte_at_eof.txt
new file mode 100644
index 000000000..269d68c74
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0009_unclosed_byte_at_eof.txt
@@ -0,0 +1,2 @@
+BYTE 2 "b\'"
+> error[0; 2) token("b\'") msg(Missing trailing `'` symbol to terminate the byte literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0010_unclosed_byte_with_ferris.rs b/crates/ra_syntax/test_data/lexer/err/0010_unclosed_byte_with_ferris.rs
new file mode 100644
index 000000000..c9230dc24
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0010_unclosed_byte_with_ferris.rs
@@ -0,0 +1 @@
+b'🦀
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0010_unclosed_byte_with_ferris.txt b/crates/ra_syntax/test_data/lexer/err/0010_unclosed_byte_with_ferris.txt
new file mode 100644
index 000000000..91a76e479
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0010_unclosed_byte_with_ferris.txt
@@ -0,0 +1,2 @@
+BYTE 6 "b\'🦀"
+> error[0; 6) token("b\'🦀") msg(Missing trailing `'` symbol to terminate the byte literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0011_unclosed_byte_with_ascii_escape.rs b/crates/ra_syntax/test_data/lexer/err/0011_unclosed_byte_with_ascii_escape.rs
new file mode 100644
index 000000000..d146a8090
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0011_unclosed_byte_with_ascii_escape.rs
@@ -0,0 +1 @@
+b'\x7f
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0011_unclosed_byte_with_ascii_escape.txt b/crates/ra_syntax/test_data/lexer/err/0011_unclosed_byte_with_ascii_escape.txt
new file mode 100644
index 000000000..b8c804a18
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0011_unclosed_byte_with_ascii_escape.txt
@@ -0,0 +1,2 @@
+BYTE 6 "b\'\\x7f"
+> error[0; 6) token("b\'\\x7f") msg(Missing trailing `'` symbol to terminate the byte literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0012_unclosed_byte_with_unicode_escape.rs b/crates/ra_syntax/test_data/lexer/err/0012_unclosed_byte_with_unicode_escape.rs
new file mode 100644
index 000000000..a3dec7c25
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0012_unclosed_byte_with_unicode_escape.rs
@@ -0,0 +1 @@
+b'\u{20AA}
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0012_unclosed_byte_with_unicode_escape.txt b/crates/ra_syntax/test_data/lexer/err/0012_unclosed_byte_with_unicode_escape.txt
new file mode 100644
index 000000000..dfca22a59
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0012_unclosed_byte_with_unicode_escape.txt
@@ -0,0 +1,2 @@
+BYTE 10 "b\'\\u{20AA}"
+> error[0; 10) token("b\'\\u{20AA}") msg(Missing trailing `'` symbol to terminate the byte literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0013_unclosed_byte_with_space.rs b/crates/ra_syntax/test_data/lexer/err/0013_unclosed_byte_with_space.rs
new file mode 100644
index 000000000..93b7f9c87
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0013_unclosed_byte_with_space.rs
@@ -0,0 +1 @@
+b' 
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0013_unclosed_byte_with_space.txt b/crates/ra_syntax/test_data/lexer/err/0013_unclosed_byte_with_space.txt
new file mode 100644
index 000000000..51a1cceab
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0013_unclosed_byte_with_space.txt
@@ -0,0 +1,2 @@
+BYTE 3 "b\' "
+> error[0; 3) token("b\' ") msg(Missing trailing `'` symbol to terminate the byte literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0014_unclosed_byte_with_slash.rs b/crates/ra_syntax/test_data/lexer/err/0014_unclosed_byte_with_slash.rs
new file mode 100644
index 000000000..abffa5037
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0014_unclosed_byte_with_slash.rs
@@ -0,0 +1 @@
+b'\
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0014_unclosed_byte_with_slash.txt b/crates/ra_syntax/test_data/lexer/err/0014_unclosed_byte_with_slash.txt
new file mode 100644
index 000000000..24e835c27
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0014_unclosed_byte_with_slash.txt
@@ -0,0 +1,2 @@
+BYTE 3 "b\'\\"
+> error[0; 3) token("b\'\\") msg(Missing trailing `'` symbol to terminate the byte literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0015_unclosed_byte_with_slash_n.rs b/crates/ra_syntax/test_data/lexer/err/0015_unclosed_byte_with_slash_n.rs
new file mode 100644
index 000000000..4f46836a9
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0015_unclosed_byte_with_slash_n.rs
@@ -0,0 +1 @@
+b'\n
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0015_unclosed_byte_with_slash_n.txt b/crates/ra_syntax/test_data/lexer/err/0015_unclosed_byte_with_slash_n.txt
new file mode 100644
index 000000000..f1e39a41b
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0015_unclosed_byte_with_slash_n.txt
@@ -0,0 +1,2 @@
+BYTE 4 "b\'\\n"
+> error[0; 4) token("b\'\\n") msg(Missing trailing `'` symbol to terminate the byte literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0016_unclosed_byte_with_slash_single_quote.rs b/crates/ra_syntax/test_data/lexer/err/0016_unclosed_byte_with_slash_single_quote.rs
new file mode 100644
index 000000000..645b641ee
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0016_unclosed_byte_with_slash_single_quote.rs
@@ -0,0 +1 @@
+b'\'
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0016_unclosed_byte_with_slash_single_quote.txt b/crates/ra_syntax/test_data/lexer/err/0016_unclosed_byte_with_slash_single_quote.txt
new file mode 100644
index 000000000..f8ffe815d
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0016_unclosed_byte_with_slash_single_quote.txt
@@ -0,0 +1,2 @@
+BYTE 4 "b\'\\\'"
+> error[0; 4) token("b\'\\\'") msg(Missing trailing `'` symbol to terminate the byte literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0017_unclosed_string_at_eof.rs b/crates/ra_syntax/test_data/lexer/err/0017_unclosed_string_at_eof.rs
new file mode 100644
index 000000000..9d68933c4
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0017_unclosed_string_at_eof.rs
@@ -0,0 +1 @@
+"
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0017_unclosed_string_at_eof.txt b/crates/ra_syntax/test_data/lexer/err/0017_unclosed_string_at_eof.txt
new file mode 100644
index 000000000..823daaf6f
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0017_unclosed_string_at_eof.txt
@@ -0,0 +1,2 @@
+STRING 1 "\""
+> error[0; 1) token("\"") msg(Missing trailing `"` symbol to terminate the string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0018_unclosed_string_with_ferris.rs b/crates/ra_syntax/test_data/lexer/err/0018_unclosed_string_with_ferris.rs
new file mode 100644
index 000000000..d439b8d2a
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0018_unclosed_string_with_ferris.rs
@@ -0,0 +1 @@
+"🦀
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0018_unclosed_string_with_ferris.txt b/crates/ra_syntax/test_data/lexer/err/0018_unclosed_string_with_ferris.txt
new file mode 100644
index 000000000..164580eb3
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0018_unclosed_string_with_ferris.txt
@@ -0,0 +1,2 @@
+STRING 5 "\"🦀"
+> error[0; 5) token("\"🦀") msg(Missing trailing `"` symbol to terminate the string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0019_unclosed_string_with_ascii_escape.rs b/crates/ra_syntax/test_data/lexer/err/0019_unclosed_string_with_ascii_escape.rs
new file mode 100644
index 000000000..56186a344
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0019_unclosed_string_with_ascii_escape.rs
@@ -0,0 +1 @@
+"\x7f
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0019_unclosed_string_with_ascii_escape.txt b/crates/ra_syntax/test_data/lexer/err/0019_unclosed_string_with_ascii_escape.txt
new file mode 100644
index 000000000..4453827c3
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0019_unclosed_string_with_ascii_escape.txt
@@ -0,0 +1,2 @@
+STRING 5 "\"\\x7f"
+> error[0; 5) token("\"\\x7f") msg(Missing trailing `"` symbol to terminate the string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0020_unclosed_string_with_unicode_escape.rs b/crates/ra_syntax/test_data/lexer/err/0020_unclosed_string_with_unicode_escape.rs
new file mode 100644
index 000000000..ed24095c3
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0020_unclosed_string_with_unicode_escape.rs
@@ -0,0 +1 @@
+"\u{20AA}
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0020_unclosed_string_with_unicode_escape.txt b/crates/ra_syntax/test_data/lexer/err/0020_unclosed_string_with_unicode_escape.txt
new file mode 100644
index 000000000..aa614f304
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0020_unclosed_string_with_unicode_escape.txt
@@ -0,0 +1,2 @@
+STRING 9 "\"\\u{20AA}"
+> error[0; 9) token("\"\\u{20AA}") msg(Missing trailing `"` symbol to terminate the string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0021_unclosed_string_with_space.rs b/crates/ra_syntax/test_data/lexer/err/0021_unclosed_string_with_space.rs
new file mode 100644
index 000000000..72cdc841f
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0021_unclosed_string_with_space.rs
@@ -0,0 +1 @@
+" 
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0021_unclosed_string_with_space.txt b/crates/ra_syntax/test_data/lexer/err/0021_unclosed_string_with_space.txt
new file mode 100644
index 000000000..b7db1236f
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0021_unclosed_string_with_space.txt
@@ -0,0 +1,2 @@
+STRING 2 "\" "
+> error[0; 2) token("\" ") msg(Missing trailing `"` symbol to terminate the string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0022_unclosed_string_with_slash.rs b/crates/ra_syntax/test_data/lexer/err/0022_unclosed_string_with_slash.rs
new file mode 100644
index 000000000..00a258400
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0022_unclosed_string_with_slash.rs
@@ -0,0 +1 @@
+"\
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0022_unclosed_string_with_slash.txt b/crates/ra_syntax/test_data/lexer/err/0022_unclosed_string_with_slash.txt
new file mode 100644
index 000000000..9d3df3799
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0022_unclosed_string_with_slash.txt
@@ -0,0 +1,2 @@
+STRING 2 "\"\\"
+> error[0; 2) token("\"\\") msg(Missing trailing `"` symbol to terminate the string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0023_unclosed_string_with_slash_n.rs b/crates/ra_syntax/test_data/lexer/err/0023_unclosed_string_with_slash_n.rs
new file mode 100644
index 000000000..a0c29b8cf
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0023_unclosed_string_with_slash_n.rs
@@ -0,0 +1 @@
+"\n
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0023_unclosed_string_with_slash_n.txt b/crates/ra_syntax/test_data/lexer/err/0023_unclosed_string_with_slash_n.txt
new file mode 100644
index 000000000..e3eb672b6
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0023_unclosed_string_with_slash_n.txt
@@ -0,0 +1,2 @@
+STRING 3 "\"\\n"
+> error[0; 3) token("\"\\n") msg(Missing trailing `"` symbol to terminate the string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0024_unclosed_string_with_slash_double_quote.rs b/crates/ra_syntax/test_data/lexer/err/0024_unclosed_string_with_slash_double_quote.rs
new file mode 100644
index 000000000..403c2d6dd
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0024_unclosed_string_with_slash_double_quote.rs
@@ -0,0 +1 @@
+"\"
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0024_unclosed_string_with_slash_double_quote.txt b/crates/ra_syntax/test_data/lexer/err/0024_unclosed_string_with_slash_double_quote.txt
new file mode 100644
index 000000000..041d7fb6e
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0024_unclosed_string_with_slash_double_quote.txt
@@ -0,0 +1,2 @@
+STRING 3 "\"\\\""
+> error[0; 3) token("\"\\\"") msg(Missing trailing `"` symbol to terminate the string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0025_unclosed_byte_string_at_eof.rs b/crates/ra_syntax/test_data/lexer/err/0025_unclosed_byte_string_at_eof.rs
new file mode 100644
index 000000000..36f4f4321
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0025_unclosed_byte_string_at_eof.rs
@@ -0,0 +1 @@
+b"
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0025_unclosed_byte_string_at_eof.txt b/crates/ra_syntax/test_data/lexer/err/0025_unclosed_byte_string_at_eof.txt
new file mode 100644
index 000000000..be7970a83
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0025_unclosed_byte_string_at_eof.txt
@@ -0,0 +1,2 @@
+BYTE_STRING 2 "b\""
+> error[0; 2) token("b\"") msg(Missing trailing `"` symbol to terminate the byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0026_unclosed_byte_string_with_ferris.rs b/crates/ra_syntax/test_data/lexer/err/0026_unclosed_byte_string_with_ferris.rs
new file mode 100644
index 000000000..3c23a0372
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0026_unclosed_byte_string_with_ferris.rs
@@ -0,0 +1 @@
+b"🦀
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0026_unclosed_byte_string_with_ferris.txt b/crates/ra_syntax/test_data/lexer/err/0026_unclosed_byte_string_with_ferris.txt
new file mode 100644
index 000000000..bf9aab132
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0026_unclosed_byte_string_with_ferris.txt
@@ -0,0 +1,2 @@
+BYTE_STRING 6 "b\"🦀"
+> error[0; 6) token("b\"🦀") msg(Missing trailing `"` symbol to terminate the byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0027_unclosed_byte_string_with_ascii_escape.rs b/crates/ra_syntax/test_data/lexer/err/0027_unclosed_byte_string_with_ascii_escape.rs
new file mode 100644
index 000000000..836c112c1
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0027_unclosed_byte_string_with_ascii_escape.rs
@@ -0,0 +1 @@
+b"\x7f
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0027_unclosed_byte_string_with_ascii_escape.txt b/crates/ra_syntax/test_data/lexer/err/0027_unclosed_byte_string_with_ascii_escape.txt
new file mode 100644
index 000000000..76e16d7d3
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0027_unclosed_byte_string_with_ascii_escape.txt
@@ -0,0 +1,2 @@
+BYTE_STRING 6 "b\"\\x7f"
+> error[0; 6) token("b\"\\x7f") msg(Missing trailing `"` symbol to terminate the byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0028_unclosed_byte_string_with_unicode_escape.rs b/crates/ra_syntax/test_data/lexer/err/0028_unclosed_byte_string_with_unicode_escape.rs
new file mode 100644
index 000000000..1c6df1d00
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0028_unclosed_byte_string_with_unicode_escape.rs
@@ -0,0 +1 @@
+b"\u{20AA}
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0028_unclosed_byte_string_with_unicode_escape.txt b/crates/ra_syntax/test_data/lexer/err/0028_unclosed_byte_string_with_unicode_escape.txt
new file mode 100644
index 000000000..09adffa16
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0028_unclosed_byte_string_with_unicode_escape.txt
@@ -0,0 +1,2 @@
+BYTE_STRING 10 "b\"\\u{20AA}"
+> error[0; 10) token("b\"\\u{20AA}") msg(Missing trailing `"` symbol to terminate the byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0029_unclosed_byte_string_with_space.rs b/crates/ra_syntax/test_data/lexer/err/0029_unclosed_byte_string_with_space.rs
new file mode 100644
index 000000000..d6898541e
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0029_unclosed_byte_string_with_space.rs
@@ -0,0 +1 @@
+b" 
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0029_unclosed_byte_string_with_space.txt b/crates/ra_syntax/test_data/lexer/err/0029_unclosed_byte_string_with_space.txt
new file mode 100644
index 000000000..fcb7253c8
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0029_unclosed_byte_string_with_space.txt
@@ -0,0 +1,2 @@
+BYTE_STRING 3 "b\" "
+> error[0; 3) token("b\" ") msg(Missing trailing `"` symbol to terminate the byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0030_unclosed_byte_string_with_slash.rs b/crates/ra_syntax/test_data/lexer/err/0030_unclosed_byte_string_with_slash.rs
new file mode 100644
index 000000000..cce661538
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0030_unclosed_byte_string_with_slash.rs
@@ -0,0 +1 @@
+b"\
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0030_unclosed_byte_string_with_slash.txt b/crates/ra_syntax/test_data/lexer/err/0030_unclosed_byte_string_with_slash.txt
new file mode 100644
index 000000000..0a1b3e269
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0030_unclosed_byte_string_with_slash.txt
@@ -0,0 +1,2 @@
+BYTE_STRING 3 "b\"\\"
+> error[0; 3) token("b\"\\") msg(Missing trailing `"` symbol to terminate the byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0031_unclosed_byte_string_with_slash_n.rs b/crates/ra_syntax/test_data/lexer/err/0031_unclosed_byte_string_with_slash_n.rs
new file mode 100644
index 000000000..5e680aabb
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0031_unclosed_byte_string_with_slash_n.rs
@@ -0,0 +1 @@
+b"\n
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0031_unclosed_byte_string_with_slash_n.txt b/crates/ra_syntax/test_data/lexer/err/0031_unclosed_byte_string_with_slash_n.txt
new file mode 100644
index 000000000..1fb89d2b6
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0031_unclosed_byte_string_with_slash_n.txt
@@ -0,0 +1,2 @@
+BYTE_STRING 4 "b\"\\n"
+> error[0; 4) token("b\"\\n") msg(Missing trailing `"` symbol to terminate the byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0032_unclosed_byte_string_with_slash_double_quote.rs b/crates/ra_syntax/test_data/lexer/err/0032_unclosed_byte_string_with_slash_double_quote.rs
new file mode 100644
index 000000000..f2ff58ba9
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0032_unclosed_byte_string_with_slash_double_quote.rs
@@ -0,0 +1 @@
+b"\"
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0032_unclosed_byte_string_with_slash_double_quote.txt b/crates/ra_syntax/test_data/lexer/err/0032_unclosed_byte_string_with_slash_double_quote.txt
new file mode 100644
index 000000000..718d36992
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0032_unclosed_byte_string_with_slash_double_quote.txt
@@ -0,0 +1,2 @@
+BYTE_STRING 4 "b\"\\\""
+> error[0; 4) token("b\"\\\"") msg(Missing trailing `"` symbol to terminate the byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0033_unclosed_raw_string_at_eof.rs b/crates/ra_syntax/test_data/lexer/err/0033_unclosed_raw_string_at_eof.rs
new file mode 100644
index 000000000..557c59b62
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0033_unclosed_raw_string_at_eof.rs
@@ -0,0 +1 @@
+r##"
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0033_unclosed_raw_string_at_eof.txt b/crates/ra_syntax/test_data/lexer/err/0033_unclosed_raw_string_at_eof.txt
new file mode 100644
index 000000000..93348f548
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0033_unclosed_raw_string_at_eof.txt
@@ -0,0 +1,2 @@
+RAW_STRING 4 "r##\""
+> error[0; 4) token("r##\"") msg(Missing trailing `"` with `#` symbols to terminate the raw string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0034_unclosed_raw_string_with_ferris.rs b/crates/ra_syntax/test_data/lexer/err/0034_unclosed_raw_string_with_ferris.rs
new file mode 100644
index 000000000..bd046e4bb
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0034_unclosed_raw_string_with_ferris.rs
@@ -0,0 +1 @@
+r##"🦀
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0034_unclosed_raw_string_with_ferris.txt b/crates/ra_syntax/test_data/lexer/err/0034_unclosed_raw_string_with_ferris.txt
new file mode 100644
index 000000000..42c70dfe8
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0034_unclosed_raw_string_with_ferris.txt
@@ -0,0 +1,2 @@
+RAW_STRING 8 "r##\"🦀"
+> error[0; 8) token("r##\"🦀") msg(Missing trailing `"` with `#` symbols to terminate the raw string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0035_unclosed_raw_string_with_ascii_escape.rs b/crates/ra_syntax/test_data/lexer/err/0035_unclosed_raw_string_with_ascii_escape.rs
new file mode 100644
index 000000000..5bec883dc
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0035_unclosed_raw_string_with_ascii_escape.rs
@@ -0,0 +1 @@
+r##"\x7f
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0035_unclosed_raw_string_with_ascii_escape.txt b/crates/ra_syntax/test_data/lexer/err/0035_unclosed_raw_string_with_ascii_escape.txt
new file mode 100644
index 000000000..2bdeea0ff
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0035_unclosed_raw_string_with_ascii_escape.txt
@@ -0,0 +1,2 @@
+RAW_STRING 8 "r##\"\\x7f"
+> error[0; 8) token("r##\"\\x7f") msg(Missing trailing `"` with `#` symbols to terminate the raw string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0036_unclosed_raw_string_with_unicode_escape.rs b/crates/ra_syntax/test_data/lexer/err/0036_unclosed_raw_string_with_unicode_escape.rs
new file mode 100644
index 000000000..bf05c3913
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0036_unclosed_raw_string_with_unicode_escape.rs
@@ -0,0 +1 @@
+r##"\u{20AA}
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0036_unclosed_raw_string_with_unicode_escape.txt b/crates/ra_syntax/test_data/lexer/err/0036_unclosed_raw_string_with_unicode_escape.txt
new file mode 100644
index 000000000..667d4d79f
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0036_unclosed_raw_string_with_unicode_escape.txt
@@ -0,0 +1,2 @@
+RAW_STRING 12 "r##\"\\u{20AA}"
+> error[0; 12) token("r##\"\\u{20AA}") msg(Missing trailing `"` with `#` symbols to terminate the raw string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0037_unclosed_raw_string_with_space.rs b/crates/ra_syntax/test_data/lexer/err/0037_unclosed_raw_string_with_space.rs
new file mode 100644
index 000000000..f104bae4f
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0037_unclosed_raw_string_with_space.rs
@@ -0,0 +1 @@
+r##" 
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0037_unclosed_raw_string_with_space.txt b/crates/ra_syntax/test_data/lexer/err/0037_unclosed_raw_string_with_space.txt
new file mode 100644
index 000000000..dd9597a1a
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0037_unclosed_raw_string_with_space.txt
@@ -0,0 +1,2 @@
+RAW_STRING 5 "r##\" "
+> error[0; 5) token("r##\" ") msg(Missing trailing `"` with `#` symbols to terminate the raw string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0038_unclosed_raw_string_with_slash.rs b/crates/ra_syntax/test_data/lexer/err/0038_unclosed_raw_string_with_slash.rs
new file mode 100644
index 000000000..9242077b8
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0038_unclosed_raw_string_with_slash.rs
@@ -0,0 +1 @@
+r##"\
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0038_unclosed_raw_string_with_slash.txt b/crates/ra_syntax/test_data/lexer/err/0038_unclosed_raw_string_with_slash.txt
new file mode 100644
index 000000000..6ac6e3d62
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0038_unclosed_raw_string_with_slash.txt
@@ -0,0 +1,2 @@
+RAW_STRING 5 "r##\"\\"
+> error[0; 5) token("r##\"\\") msg(Missing trailing `"` with `#` symbols to terminate the raw string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0039_unclosed_raw_string_with_slash_n.rs b/crates/ra_syntax/test_data/lexer/err/0039_unclosed_raw_string_with_slash_n.rs
new file mode 100644
index 000000000..db1c16f2b
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0039_unclosed_raw_string_with_slash_n.rs
@@ -0,0 +1 @@
+r##"\n
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0039_unclosed_raw_string_with_slash_n.txt b/crates/ra_syntax/test_data/lexer/err/0039_unclosed_raw_string_with_slash_n.txt
new file mode 100644
index 000000000..9d35443f5
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0039_unclosed_raw_string_with_slash_n.txt
@@ -0,0 +1,2 @@
+RAW_STRING 6 "r##\"\\n"
+> error[0; 6) token("r##\"\\n") msg(Missing trailing `"` with `#` symbols to terminate the raw string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0040_unclosed_raw_byte_string_at_eof.rs b/crates/ra_syntax/test_data/lexer/err/0040_unclosed_raw_byte_string_at_eof.rs
new file mode 100644
index 000000000..ae5bae622
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0040_unclosed_raw_byte_string_at_eof.rs
@@ -0,0 +1 @@
+br##"
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0040_unclosed_raw_byte_string_at_eof.txt b/crates/ra_syntax/test_data/lexer/err/0040_unclosed_raw_byte_string_at_eof.txt
new file mode 100644
index 000000000..81fa39ea5
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0040_unclosed_raw_byte_string_at_eof.txt
@@ -0,0 +1,2 @@
+RAW_BYTE_STRING 5 "br##\""
+> error[0; 5) token("br##\"") msg(Missing trailing `"` with `#` symbols to terminate the raw byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0041_unclosed_raw_byte_string_with_ferris.rs b/crates/ra_syntax/test_data/lexer/err/0041_unclosed_raw_byte_string_with_ferris.rs
new file mode 100644
index 000000000..9ef01207a
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0041_unclosed_raw_byte_string_with_ferris.rs
@@ -0,0 +1 @@
+br##"🦀
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0041_unclosed_raw_byte_string_with_ferris.txt b/crates/ra_syntax/test_data/lexer/err/0041_unclosed_raw_byte_string_with_ferris.txt
new file mode 100644
index 000000000..c2503a4d0
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0041_unclosed_raw_byte_string_with_ferris.txt
@@ -0,0 +1,2 @@
+RAW_BYTE_STRING 9 "br##\"🦀"
+> error[0; 9) token("br##\"🦀") msg(Missing trailing `"` with `#` symbols to terminate the raw byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0042_unclosed_raw_byte_string_with_ascii_escape.rs b/crates/ra_syntax/test_data/lexer/err/0042_unclosed_raw_byte_string_with_ascii_escape.rs
new file mode 100644
index 000000000..d50270afe
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0042_unclosed_raw_byte_string_with_ascii_escape.rs
@@ -0,0 +1 @@
+br##"\x7f
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0042_unclosed_raw_byte_string_with_ascii_escape.txt b/crates/ra_syntax/test_data/lexer/err/0042_unclosed_raw_byte_string_with_ascii_escape.txt
new file mode 100644
index 000000000..3bd3d8152
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0042_unclosed_raw_byte_string_with_ascii_escape.txt
@@ -0,0 +1,2 @@
+RAW_BYTE_STRING 9 "br##\"\\x7f"
+> error[0; 9) token("br##\"\\x7f") msg(Missing trailing `"` with `#` symbols to terminate the raw byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0043_unclosed_raw_byte_string_with_unicode_escape.rs b/crates/ra_syntax/test_data/lexer/err/0043_unclosed_raw_byte_string_with_unicode_escape.rs
new file mode 100644
index 000000000..90e299a1a
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0043_unclosed_raw_byte_string_with_unicode_escape.rs
@@ -0,0 +1 @@
+br##"\u{20AA}
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0043_unclosed_raw_byte_string_with_unicode_escape.txt b/crates/ra_syntax/test_data/lexer/err/0043_unclosed_raw_byte_string_with_unicode_escape.txt
new file mode 100644
index 000000000..a512f0428
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0043_unclosed_raw_byte_string_with_unicode_escape.txt
@@ -0,0 +1,2 @@
+RAW_BYTE_STRING 13 "br##\"\\u{20AA}"
+> error[0; 13) token("br##\"\\u{20AA}") msg(Missing trailing `"` with `#` symbols to terminate the raw byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0044_unclosed_raw_byte_string_with_space.rs b/crates/ra_syntax/test_data/lexer/err/0044_unclosed_raw_byte_string_with_space.rs
new file mode 100644
index 000000000..14c602fd2
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0044_unclosed_raw_byte_string_with_space.rs
@@ -0,0 +1 @@
+br##" 
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0044_unclosed_raw_byte_string_with_space.txt b/crates/ra_syntax/test_data/lexer/err/0044_unclosed_raw_byte_string_with_space.txt
new file mode 100644
index 000000000..dc616a623
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0044_unclosed_raw_byte_string_with_space.txt
@@ -0,0 +1,2 @@
+RAW_BYTE_STRING 6 "br##\" "
+> error[0; 6) token("br##\" ") msg(Missing trailing `"` with `#` symbols to terminate the raw byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0045_unclosed_raw_byte_string_with_slash.rs b/crates/ra_syntax/test_data/lexer/err/0045_unclosed_raw_byte_string_with_slash.rs
new file mode 100644
index 000000000..0b3c015d7
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0045_unclosed_raw_byte_string_with_slash.rs
@@ -0,0 +1 @@
+br##"\
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0045_unclosed_raw_byte_string_with_slash.txt b/crates/ra_syntax/test_data/lexer/err/0045_unclosed_raw_byte_string_with_slash.txt
new file mode 100644
index 000000000..debafe380
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0045_unclosed_raw_byte_string_with_slash.txt
@@ -0,0 +1,2 @@
+RAW_BYTE_STRING 6 "br##\"\\"
+> error[0; 6) token("br##\"\\") msg(Missing trailing `"` with `#` symbols to terminate the raw byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0046_unclosed_raw_byte_string_with_slash_n.rs b/crates/ra_syntax/test_data/lexer/err/0046_unclosed_raw_byte_string_with_slash_n.rs
new file mode 100644
index 000000000..0d8b0e7ab
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0046_unclosed_raw_byte_string_with_slash_n.rs
@@ -0,0 +1 @@
+br##"\n
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0046_unclosed_raw_byte_string_with_slash_n.txt b/crates/ra_syntax/test_data/lexer/err/0046_unclosed_raw_byte_string_with_slash_n.txt
new file mode 100644
index 000000000..524e617b7
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0046_unclosed_raw_byte_string_with_slash_n.txt
@@ -0,0 +1,2 @@
+RAW_BYTE_STRING 7 "br##\"\\n"
+> error[0; 7) token("br##\"\\n") msg(Missing trailing `"` with `#` symbols to terminate the raw byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0047_unstarted_raw_string_at_eof.rs b/crates/ra_syntax/test_data/lexer/err/0047_unstarted_raw_string_at_eof.rs
new file mode 100644
index 000000000..eddf8d080
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0047_unstarted_raw_string_at_eof.rs
@@ -0,0 +1 @@
+r##
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0047_unstarted_raw_string_at_eof.txt b/crates/ra_syntax/test_data/lexer/err/0047_unstarted_raw_string_at_eof.txt
new file mode 100644
index 000000000..00b046840
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0047_unstarted_raw_string_at_eof.txt
@@ -0,0 +1,2 @@
+RAW_STRING 3 "r##"
+> error[0; 3) token("r##") msg(Missing `"` symbol after `#` symbols to begin the raw string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0048_unstarted_raw_byte_string_at_eof.rs b/crates/ra_syntax/test_data/lexer/err/0048_unstarted_raw_byte_string_at_eof.rs
new file mode 100644
index 000000000..7e8cadf4f
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0048_unstarted_raw_byte_string_at_eof.rs
@@ -0,0 +1 @@
+br##
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0048_unstarted_raw_byte_string_at_eof.txt b/crates/ra_syntax/test_data/lexer/err/0048_unstarted_raw_byte_string_at_eof.txt
new file mode 100644
index 000000000..33b25e60f
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0048_unstarted_raw_byte_string_at_eof.txt
@@ -0,0 +1,2 @@
+RAW_BYTE_STRING 4 "br##"
+> error[0; 4) token("br##") msg(Missing `"` symbol after `#` symbols to begin the raw byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0049_unstarted_raw_string_with_ascii.rs b/crates/ra_syntax/test_data/lexer/err/0049_unstarted_raw_string_with_ascii.rs
new file mode 100644
index 000000000..534668a9b
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0049_unstarted_raw_string_with_ascii.rs
@@ -0,0 +1 @@
+r## I lack a quote!
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0049_unstarted_raw_string_with_ascii.txt b/crates/ra_syntax/test_data/lexer/err/0049_unstarted_raw_string_with_ascii.txt
new file mode 100644
index 000000000..782dfd974
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0049_unstarted_raw_string_with_ascii.txt
@@ -0,0 +1,10 @@
+RAW_STRING 4 "r## "
+IDENT 1 "I"
+WHITESPACE 1 " "
+IDENT 4 "lack"
+WHITESPACE 1 " "
+IDENT 1 "a"
+WHITESPACE 1 " "
+IDENT 5 "quote"
+EXCL 1 "!"
+> error[0; 4) token("r## ") msg(Missing `"` symbol after `#` symbols to begin the raw string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0050_unstarted_raw_byte_string_with_ascii.rs b/crates/ra_syntax/test_data/lexer/err/0050_unstarted_raw_byte_string_with_ascii.rs
new file mode 100644
index 000000000..d9b55455a
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0050_unstarted_raw_byte_string_with_ascii.rs
@@ -0,0 +1 @@
+br## I lack a quote!
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0050_unstarted_raw_byte_string_with_ascii.txt b/crates/ra_syntax/test_data/lexer/err/0050_unstarted_raw_byte_string_with_ascii.txt
new file mode 100644
index 000000000..59c40cd65
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0050_unstarted_raw_byte_string_with_ascii.txt
@@ -0,0 +1,10 @@
+RAW_BYTE_STRING 5 "br## "
+IDENT 1 "I"
+WHITESPACE 1 " "
+IDENT 4 "lack"
+WHITESPACE 1 " "
+IDENT 1 "a"
+WHITESPACE 1 " "
+IDENT 5 "quote"
+EXCL 1 "!"
+> error[0; 5) token("br## ") msg(Missing `"` symbol after `#` symbols to begin the raw byte string literal)
diff --git a/crates/ra_syntax/test_data/lexer/err/0051_unclosed_block_comment_at_eof.rs b/crates/ra_syntax/test_data/lexer/err/0051_unclosed_block_comment_at_eof.rs
new file mode 100644
index 000000000..22e83649f
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0051_unclosed_block_comment_at_eof.rs
@@ -0,0 +1 @@
+/*
+\ No newline at end of file
diff --git a/crates/ra_syntax/test_data/lexer/err/0051_unclosed_block_comment_at_eof.txt b/crates/ra_syntax/test_data/lexer/err/0051_unclosed_block_comment_at_eof.txt
new file mode 100644
index 000000000..5d04cdaa4
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0051_unclosed_block_comment_at_eof.txt
@@ -0,0 +1,2 @@
+COMMENT 2 "/*"
+> error[0; 2) token("/*") msg(Missing trailing `*/` symbols to terminate the block comment)
diff --git a/crates/ra_syntax/test_data/lexer/err/0052_unclosed_block_comment_with_content.rs b/crates/ra_syntax/test_data/lexer/err/0052_unclosed_block_comment_with_content.rs
new file mode 100644
index 000000000..c45c2844d
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0052_unclosed_block_comment_with_content.rs
@@ -0,0 +1 @@
+/* comment
diff --git a/crates/ra_syntax/test_data/lexer/err/0052_unclosed_block_comment_with_content.txt b/crates/ra_syntax/test_data/lexer/err/0052_unclosed_block_comment_with_content.txt
new file mode 100644
index 000000000..8c6b678e3
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0052_unclosed_block_comment_with_content.txt
@@ -0,0 +1,2 @@
+COMMENT 11 "/* comment\n"
+> error[0; 11) token("/* comment\n") msg(Missing trailing `*/` symbols to terminate the block comment)
diff --git a/crates/ra_syntax/test_data/lexer/err/0053_unclosed_nested_block_comment_entirely.rs b/crates/ra_syntax/test_data/lexer/err/0053_unclosed_nested_block_comment_entirely.rs
new file mode 100644
index 000000000..3fcfc9660
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0053_unclosed_nested_block_comment_entirely.rs
@@ -0,0 +1 @@
+/* /* /*
diff --git a/crates/ra_syntax/test_data/lexer/err/0053_unclosed_nested_block_comment_entirely.txt b/crates/ra_syntax/test_data/lexer/err/0053_unclosed_nested_block_comment_entirely.txt
new file mode 100644
index 000000000..250de34d9
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0053_unclosed_nested_block_comment_entirely.txt
@@ -0,0 +1,2 @@
+COMMENT 9 "/* /* /*\n"
+> error[0; 9) token("/* /* /*\n") msg(Missing trailing `*/` symbols to terminate the block comment)
diff --git a/crates/ra_syntax/test_data/lexer/err/0054_unclosed_nested_block_comment_partially.rs b/crates/ra_syntax/test_data/lexer/err/0054_unclosed_nested_block_comment_partially.rs
new file mode 100644
index 000000000..26c898f01
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0054_unclosed_nested_block_comment_partially.rs
@@ -0,0 +1 @@
+/** /*! /* comment */ */
diff --git a/crates/ra_syntax/test_data/lexer/err/0054_unclosed_nested_block_comment_partially.txt b/crates/ra_syntax/test_data/lexer/err/0054_unclosed_nested_block_comment_partially.txt
new file mode 100644
index 000000000..f97f2a8c7
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0054_unclosed_nested_block_comment_partially.txt
@@ -0,0 +1,2 @@
+COMMENT 25 "/** /*! /* comment */ */\n"
+> error[0; 25) token("/** /*! /* comment */ */\n") msg(Missing trailing `*/` symbols to terminate the block comment)
diff --git a/crates/ra_syntax/test_data/lexer/err/0055_empty_int.rs b/crates/ra_syntax/test_data/lexer/err/0055_empty_int.rs
new file mode 100644
index 000000000..aa2a9fdca
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0055_empty_int.rs
@@ -0,0 +1,17 @@
+0b
+0o
+0x
+0b_
+0o_
+0x_
+0bnoDigit
+0onoDigit
+0xnoDigit
+0xG
+0xg
+0x_g
+0x_G
diff --git a/crates/ra_syntax/test_data/lexer/err/0055_empty_int.txt b/crates/ra_syntax/test_data/lexer/err/0055_empty_int.txt
new file mode 100644
index 000000000..2fe5bd950
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0055_empty_int.txt
@@ -0,0 +1,39 @@
+INT_NUMBER 2 "0b"
+WHITESPACE 1 "\n"
+INT_NUMBER 2 "0o"
+WHITESPACE 1 "\n"
+INT_NUMBER 2 "0x"
+WHITESPACE 2 "\n\n"
+INT_NUMBER 3 "0b_"
+WHITESPACE 1 "\n"
+INT_NUMBER 3 "0o_"
+WHITESPACE 1 "\n"
+INT_NUMBER 3 "0x_"
+WHITESPACE 2 "\n\n"
+INT_NUMBER 9 "0bnoDigit"
+WHITESPACE 1 "\n"
+INT_NUMBER 9 "0onoDigit"
+WHITESPACE 1 "\n"
+INT_NUMBER 9 "0xnoDigit"
+WHITESPACE 2 "\n\n"
+INT_NUMBER 3 "0xG"
+WHITESPACE 1 "\n"
+INT_NUMBER 3 "0xg"
+WHITESPACE 2 "\n\n"
+INT_NUMBER 4 "0x_g"
+WHITESPACE 1 "\n"
+INT_NUMBER 4 "0x_G"
+WHITESPACE 1 "\n"
+> error[0; 2) token("0b") msg(Missing digits after the integer base prefix)
+> error[3; 5) token("0o") msg(Missing digits after the integer base prefix)
+> error[6; 8) token("0x") msg(Missing digits after the integer base prefix)
+> error[10; 13) token("0b_") msg(Missing digits after the integer base prefix)
+> error[14; 17) token("0o_") msg(Missing digits after the integer base prefix)
+> error[18; 21) token("0x_") msg(Missing digits after the integer base prefix)
+> error[23; 32) token("0bnoDigit") msg(Missing digits after the integer base prefix)
+> error[33; 42) token("0onoDigit") msg(Missing digits after the integer base prefix)
+> error[43; 52) token("0xnoDigit") msg(Missing digits after the integer base prefix)
+> error[54; 57) token("0xG") msg(Missing digits after the integer base prefix)
+> error[58; 61) token("0xg") msg(Missing digits after the integer base prefix)
+> error[63; 67) token("0x_g") msg(Missing digits after the integer base prefix)
+> error[68; 72) token("0x_G") msg(Missing digits after the integer base prefix)
diff --git a/crates/ra_syntax/test_data/lexer/err/0056_empty_exponent.rs b/crates/ra_syntax/test_data/lexer/err/0056_empty_exponent.rs
new file mode 100644
index 000000000..286584c88
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0056_empty_exponent.rs
@@ -0,0 +1,22 @@
+0e
+0E
+42e+
+42e-
+42E+
+42E-
+42.e+
+42.e-
+42.E+
+42.E-
+42.2e+
+42.2e-
+42.2E+
+42.2E-
+42.2e+f32
+42.2e-f32
+42.2E+f32
+42.2E-f32
diff --git a/crates/ra_syntax/test_data/lexer/err/0056_empty_exponent.txt b/crates/ra_syntax/test_data/lexer/err/0056_empty_exponent.txt
new file mode 100644
index 000000000..ab35e20a5
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0056_empty_exponent.txt
@@ -0,0 +1,62 @@
+FLOAT_NUMBER 2 "0e"
+WHITESPACE 1 "\n"
+FLOAT_NUMBER 2 "0E"
+WHITESPACE 2 "\n\n"
+FLOAT_NUMBER 4 "42e+"
+WHITESPACE 1 "\n"
+FLOAT_NUMBER 4 "42e-"
+WHITESPACE 1 "\n"
+FLOAT_NUMBER 4 "42E+"
+WHITESPACE 1 "\n"
+FLOAT_NUMBER 4 "42E-"
+WHITESPACE 2 "\n\n"
+INT_NUMBER 2 "42"
+DOT 1 "."
+IDENT 1 "e"
+PLUS 1 "+"
+WHITESPACE 1 "\n"
+INT_NUMBER 2 "42"
+DOT 1 "."
+IDENT 1 "e"
+MINUS 1 "-"
+WHITESPACE 1 "\n"
+INT_NUMBER 2 "42"
+DOT 1 "."
+IDENT 1 "E"
+PLUS 1 "+"
+WHITESPACE 1 "\n"
+INT_NUMBER 2 "42"
+DOT 1 "."
+IDENT 1 "E"
+MINUS 1 "-"
+WHITESPACE 2 "\n\n"
+FLOAT_NUMBER 6 "42.2e+"
+WHITESPACE 1 "\n"
+FLOAT_NUMBER 6 "42.2e-"
+WHITESPACE 1 "\n"
+FLOAT_NUMBER 6 "42.2E+"
+WHITESPACE 1 "\n"
+FLOAT_NUMBER 6 "42.2E-"
+WHITESPACE 2 "\n\n"
+FLOAT_NUMBER 9 "42.2e+f32"
+WHITESPACE 1 "\n"
+FLOAT_NUMBER 9 "42.2e-f32"
+WHITESPACE 1 "\n"
+FLOAT_NUMBER 9 "42.2E+f32"
+WHITESPACE 1 "\n"
+FLOAT_NUMBER 9 "42.2E-f32"
+WHITESPACE 1 "\n"
+> error[0; 2) token("0e") msg(Missing digits after the exponent symbol)
+> error[3; 5) token("0E") msg(Missing digits after the exponent symbol)
+> error[7; 11) token("42e+") msg(Missing digits after the exponent symbol)
+> error[12; 16) token("42e-") msg(Missing digits after the exponent symbol)
+> error[17; 21) token("42E+") msg(Missing digits after the exponent symbol)
+> error[22; 26) token("42E-") msg(Missing digits after the exponent symbol)
+> error[53; 59) token("42.2e+") msg(Missing digits after the exponent symbol)
+> error[60; 66) token("42.2e-") msg(Missing digits after the exponent symbol)
+> error[67; 73) token("42.2E+") msg(Missing digits after the exponent symbol)
+> error[74; 80) token("42.2E-") msg(Missing digits after the exponent symbol)
+> error[82; 91) token("42.2e+f32") msg(Missing digits after the exponent symbol)
+> error[92; 101) token("42.2e-f32") msg(Missing digits after the exponent symbol)
+> error[102; 111) token("42.2E+f32") msg(Missing digits after the exponent symbol)
+> error[112; 121) token("42.2E-f32") msg(Missing digits after the exponent symbol)
diff --git a/crates/ra_syntax/test_data/lexer/err/0057_lifetime_strarts_with_a_number.rs b/crates/ra_syntax/test_data/lexer/err/0057_lifetime_strarts_with_a_number.rs
new file mode 100644
index 000000000..a7698a404
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0057_lifetime_strarts_with_a_number.rs
@@ -0,0 +1,2 @@
+'1
+'1lifetime
diff --git a/crates/ra_syntax/test_data/lexer/err/0057_lifetime_strarts_with_a_number.txt b/crates/ra_syntax/test_data/lexer/err/0057_lifetime_strarts_with_a_number.txt
new file mode 100644
index 000000000..89b38bfac
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/err/0057_lifetime_strarts_with_a_number.txt
@@ -0,0 +1,6 @@
+LIFETIME 2 "\'1"
+WHITESPACE 1 "\n"
+LIFETIME 10 "\'1lifetime"
+WHITESPACE 1 "\n"
+> error[0; 2) token("\'1") msg(Lifetime name cannot start with a number)
+> error[3; 13) token("\'1lifetime") msg(Lifetime name cannot start with a number)
diff --git a/crates/ra_syntax/test_data/lexer/0001_hello.rs b/crates/ra_syntax/test_data/lexer/ok/0001_hello.rs
index 95d09f2b1..95d09f2b1 100644
--- a/crates/ra_syntax/test_data/lexer/0001_hello.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0001_hello.rs
diff --git a/crates/ra_syntax/test_data/lexer/0001_hello.txt b/crates/ra_syntax/test_data/lexer/ok/0001_hello.txt
index 27a5940a9..27a5940a9 100644
--- a/crates/ra_syntax/test_data/lexer/0001_hello.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0001_hello.txt
diff --git a/crates/ra_syntax/test_data/lexer/0002_whitespace.rs b/crates/ra_syntax/test_data/lexer/ok/0002_whitespace.rs
index 08fce1418..08fce1418 100644
--- a/crates/ra_syntax/test_data/lexer/0002_whitespace.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0002_whitespace.rs
diff --git a/crates/ra_syntax/test_data/lexer/0002_whitespace.txt b/crates/ra_syntax/test_data/lexer/ok/0002_whitespace.txt
index 01d260918..01d260918 100644
--- a/crates/ra_syntax/test_data/lexer/0002_whitespace.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0002_whitespace.txt
diff --git a/crates/ra_syntax/test_data/lexer/0003_ident.rs b/crates/ra_syntax/test_data/lexer/ok/0003_ident.rs
index c05c9c009..c05c9c009 100644
--- a/crates/ra_syntax/test_data/lexer/0003_ident.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0003_ident.rs
diff --git a/crates/ra_syntax/test_data/lexer/0003_ident.txt b/crates/ra_syntax/test_data/lexer/ok/0003_ident.txt
index 4a0d5c053..4a0d5c053 100644
--- a/crates/ra_syntax/test_data/lexer/0003_ident.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0003_ident.txt
diff --git a/crates/ra_syntax/test_data/lexer/0004_numbers.rs b/crates/ra_syntax/test_data/lexer/ok/0004_numbers.rs
index dc974b553..bc761c235 100644
--- a/crates/ra_syntax/test_data/lexer/0004_numbers.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0004_numbers.rs
@@ -1,4 +1,4 @@
-0 0b 0o 0x 00 0_ 0. 0e 0E 0z
+0 00 0_ 0. 0z
 01790 0b1790 0o1790 0x1790aAbBcCdDeEfF 001279 0_1279 0.1279 0e1279 0E1279
 0..2
 0.foo()
@@ -6,4 +6,4 @@
 0.e+1
 0.0E-2
 0___0.10000____0000e+111__
-1i64 92.0f32 11__s
-\ No newline at end of file
+1i64 92.0f32 11__s
diff --git a/crates/ra_syntax/test_data/lexer/0004_numbers.txt b/crates/ra_syntax/test_data/lexer/ok/0004_numbers.txt
index 7bb89b8ae..e19fc5789 100644
--- a/crates/ra_syntax/test_data/lexer/0004_numbers.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0004_numbers.txt
@@ -1,21 +1,11 @@
 INT_NUMBER 1 "0"
 WHITESPACE 1 " "
-INT_NUMBER 2 "0b"
-WHITESPACE 1 " "
-INT_NUMBER 2 "0o"
-WHITESPACE 1 " "
-INT_NUMBER 2 "0x"
-WHITESPACE 1 " "
 INT_NUMBER 2 "00"
 WHITESPACE 1 " "
 INT_NUMBER 2 "0_"
 WHITESPACE 1 " "
 FLOAT_NUMBER 2 "0."
 WHITESPACE 1 " "
-FLOAT_NUMBER 2 "0e"
-WHITESPACE 1 " "
-FLOAT_NUMBER 2 "0E"
-WHITESPACE 1 " "
 INT_NUMBER 2 "0z"
 WHITESPACE 1 "\n"
 INT_NUMBER 5 "01790"
@@ -64,3 +54,4 @@ WHITESPACE 1 " "
 FLOAT_NUMBER 7 "92.0f32"
 WHITESPACE 1 " "
 INT_NUMBER 5 "11__s"
+WHITESPACE 1 "\n"
diff --git a/crates/ra_syntax/test_data/lexer/0005_symbols.rs b/crates/ra_syntax/test_data/lexer/ok/0005_symbols.rs
index 487569b5a..487569b5a 100644
--- a/crates/ra_syntax/test_data/lexer/0005_symbols.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0005_symbols.rs
diff --git a/crates/ra_syntax/test_data/lexer/0005_symbols.txt b/crates/ra_syntax/test_data/lexer/ok/0005_symbols.txt
index 469a90e42..469a90e42 100644
--- a/crates/ra_syntax/test_data/lexer/0005_symbols.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0005_symbols.txt
diff --git a/crates/ra_syntax/test_data/lexer/0006_chars.rs b/crates/ra_syntax/test_data/lexer/ok/0006_chars.rs
index 454ee0a5f..454ee0a5f 100644
--- a/crates/ra_syntax/test_data/lexer/0006_chars.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0006_chars.rs
diff --git a/crates/ra_syntax/test_data/lexer/0006_chars.txt b/crates/ra_syntax/test_data/lexer/ok/0006_chars.txt
index 950954fbc..950954fbc 100644
--- a/crates/ra_syntax/test_data/lexer/0006_chars.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0006_chars.txt
diff --git a/crates/ra_syntax/test_data/lexer/0007_lifetimes.rs b/crates/ra_syntax/test_data/lexer/ok/0007_lifetimes.rs
index b764f1dce..b764f1dce 100644
--- a/crates/ra_syntax/test_data/lexer/0007_lifetimes.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0007_lifetimes.rs
diff --git a/crates/ra_syntax/test_data/lexer/0007_lifetimes.txt b/crates/ra_syntax/test_data/lexer/ok/0007_lifetimes.txt
index 005c29100..005c29100 100644
--- a/crates/ra_syntax/test_data/lexer/0007_lifetimes.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0007_lifetimes.txt
diff --git a/crates/ra_syntax/test_data/lexer/0008_byte_strings.rs b/crates/ra_syntax/test_data/lexer/ok/0008_byte_strings.rs
index b54930f5e..b54930f5e 100644
--- a/crates/ra_syntax/test_data/lexer/0008_byte_strings.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0008_byte_strings.rs
diff --git a/crates/ra_syntax/test_data/lexer/0008_byte_strings.txt b/crates/ra_syntax/test_data/lexer/ok/0008_byte_strings.txt
index bc03b51a8..bc03b51a8 100644
--- a/crates/ra_syntax/test_data/lexer/0008_byte_strings.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0008_byte_strings.txt
diff --git a/crates/ra_syntax/test_data/lexer/0009_strings.rs b/crates/ra_syntax/test_data/lexer/ok/0009_strings.rs
index 4ddb5bffc..4ddb5bffc 100644
--- a/crates/ra_syntax/test_data/lexer/0009_strings.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0009_strings.rs
diff --git a/crates/ra_syntax/test_data/lexer/0009_strings.txt b/crates/ra_syntax/test_data/lexer/ok/0009_strings.txt
index 4cb4d711d..4cb4d711d 100644
--- a/crates/ra_syntax/test_data/lexer/0009_strings.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0009_strings.txt
diff --git a/crates/ra_syntax/test_data/lexer/ok/0010_single_line_comments.rs b/crates/ra_syntax/test_data/lexer/ok/0010_single_line_comments.rs
new file mode 100644
index 000000000..4b6653f9c
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/ok/0010_single_line_comments.rs
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+// hello
+//! World
+//!! Inner line doc
+/// Outer line doc
+//// Just a comment
+//
+//!
+//!!
+///
+////
diff --git a/crates/ra_syntax/test_data/lexer/ok/0010_single_line_comments.txt b/crates/ra_syntax/test_data/lexer/ok/0010_single_line_comments.txt
new file mode 100644
index 000000000..98a3818c0
--- /dev/null
+++ b/crates/ra_syntax/test_data/lexer/ok/0010_single_line_comments.txt
@@ -0,0 +1,22 @@
+SHEBANG 19 "#!/usr/bin/env bash"
+WHITESPACE 1 "\n"
+COMMENT 8 "// hello"
+WHITESPACE 1 "\n"
+COMMENT 9 "//! World"
+WHITESPACE 1 "\n"
+COMMENT 19 "//!! Inner line doc"
+WHITESPACE 1 "\n"
+COMMENT 18 "/// Outer line doc"
+WHITESPACE 1 "\n"
+COMMENT 19 "//// Just a comment"
+WHITESPACE 2 "\n\n"
+COMMENT 2 "//"
+WHITESPACE 1 "\n"
+COMMENT 3 "//!"
+WHITESPACE 1 "\n"
+COMMENT 4 "//!!"
+WHITESPACE 1 "\n"
+COMMENT 3 "///"
+WHITESPACE 1 "\n"
+COMMENT 4 "////"
+WHITESPACE 1 "\n"
diff --git a/crates/ra_syntax/test_data/lexer/0011_keywords.rs b/crates/ra_syntax/test_data/lexer/ok/0011_keywords.rs
index 1e91bff4e..1e91bff4e 100644
--- a/crates/ra_syntax/test_data/lexer/0011_keywords.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0011_keywords.rs
diff --git a/crates/ra_syntax/test_data/lexer/0011_keywords.txt b/crates/ra_syntax/test_data/lexer/ok/0011_keywords.txt
index 22c00eefb..22c00eefb 100644
--- a/crates/ra_syntax/test_data/lexer/0011_keywords.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0011_keywords.txt
diff --git a/crates/ra_syntax/test_data/lexer/00012_block_comment.rs b/crates/ra_syntax/test_data/lexer/ok/0012_block_comment.rs
index 708aac197..b880a59d9 100644
--- a/crates/ra_syntax/test_data/lexer/00012_block_comment.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0012_block_comment.rs
@@ -1,4 +1,3 @@
 /* */
 /**/
 /* /* */ */
-/*
diff --git a/crates/ra_syntax/test_data/lexer/00012_block_comment.txt b/crates/ra_syntax/test_data/lexer/ok/0012_block_comment.txt
index 9958b2518..2618e287e 100644
--- a/crates/ra_syntax/test_data/lexer/00012_block_comment.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0012_block_comment.txt
@@ -4,4 +4,3 @@ COMMENT 4 "/**/"
 WHITESPACE 1 "\n"
 COMMENT 11 "/* /* */ */"
 WHITESPACE 1 "\n"
-COMMENT 3 "/*\n"
diff --git a/crates/ra_syntax/test_data/lexer/0013_raw_strings.rs b/crates/ra_syntax/test_data/lexer/ok/0013_raw_strings.rs
index e5ed0b693..e5ed0b693 100644
--- a/crates/ra_syntax/test_data/lexer/0013_raw_strings.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0013_raw_strings.rs
diff --git a/crates/ra_syntax/test_data/lexer/0013_raw_strings.txt b/crates/ra_syntax/test_data/lexer/ok/0013_raw_strings.txt
index 9cf0957d1..9cf0957d1 100644
--- a/crates/ra_syntax/test_data/lexer/0013_raw_strings.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0013_raw_strings.txt
diff --git a/crates/ra_syntax/test_data/lexer/0016_raw_ident.rs b/crates/ra_syntax/test_data/lexer/ok/0014_raw_ident.rs
index b40a1b6a2..b40a1b6a2 100644
--- a/crates/ra_syntax/test_data/lexer/0016_raw_ident.rs
+++ b/crates/ra_syntax/test_data/lexer/ok/0014_raw_ident.rs
diff --git a/crates/ra_syntax/test_data/lexer/0016_raw_ident.txt b/crates/ra_syntax/test_data/lexer/ok/0014_raw_ident.txt
index 484689693..484689693 100644
--- a/crates/ra_syntax/test_data/lexer/0016_raw_ident.txt
+++ b/crates/ra_syntax/test_data/lexer/ok/0014_raw_ident.txt