27 files changed, 164 insertions, 76 deletions

diff --git a/crates/ide/Cargo.toml b/crates/ide/Cargo.toml
index 63299dc31..4d483580d 100644
--- a/crates/ide/Cargo.toml
+++ b/crates/ide/Cargo.toml
@@ -11,7 +11,7 @@ doctest = false
 
 [dependencies]
 either = "1.5.3"
-indexmap = "1.3.2"
+indexmap = "1.4.0"
 itertools = "0.9.0"
 log = "0.4.8"
 rustc-hash = "1.1.0"
@@ -23,14 +23,12 @@ url = "2.1.1"
 stdx = { path = "../stdx", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
 text_edit = { path = "../text_edit", version = "0.0.0" }
-base_db = { path = "../base_db", version = "0.0.0" }
 ide_db = { path = "../ide_db", version = "0.0.0" }
 cfg = { path = "../cfg", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
 test_utils = { path = "../test_utils", version = "0.0.0" }
 assists = { path = "../assists", version = "0.0.0" }
 ssr = { path = "../ssr", version = "0.0.0" }
-call_info = { path = "../call_info", version = "0.0.0" }
 completion = { path = "../completion", version = "0.0.0" }
 
 # ide should depend only on the top-level `hir` package. if you need
diff --git a/crates/ide/src/call_hierarchy.rs b/crates/ide/src/call_hierarchy.rs
index 9d6433fe0..8ad50a2ee 100644
--- a/crates/ide/src/call_hierarchy.rs
+++ b/crates/ide/src/call_hierarchy.rs
@@ -2,8 +2,8 @@
 
 use indexmap::IndexMap;
 
-use call_info::FnCallNode;
 use hir::Semantics;
+use ide_db::call_info::FnCallNode;
 use ide_db::RootDatabase;
 use syntax::{ast, match_ast, AstNode, TextRange};
 
@@ -137,7 +137,7 @@ impl CallLocations {
 
 #[cfg(test)]
 mod tests {
-    use base_db::FilePosition;
+    use ide_db::base_db::FilePosition;
 
     use crate::fixture;
 
diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index 90574cb35..d0ee58858 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -9,11 +9,11 @@ mod field_shorthand;
 
 use std::cell::RefCell;
 
-use base_db::SourceDatabase;
 use hir::{
     diagnostics::{Diagnostic as _, DiagnosticSinkBuilder},
     Semantics,
 };
+use ide_db::base_db::SourceDatabase;
 use ide_db::RootDatabase;
 use itertools::Itertools;
 use rustc_hash::FxHashSet;
@@ -613,7 +613,7 @@ fn main() {
 pub struct Foo { pub a: i32, pub b: i32 }
 "#,
             r#"
-fn {a:42, b: ()} {}
+fn some(, b: ()} {}
 fn items() {}
 fn here() {}
 
diff --git a/crates/ide/src/diagnostics/field_shorthand.rs b/crates/ide/src/diagnostics/field_shorthand.rs
index 54e9fce9e..f41bcd619 100644
--- a/crates/ide/src/diagnostics/field_shorthand.rs
+++ b/crates/ide/src/diagnostics/field_shorthand.rs
@@ -1,7 +1,7 @@
 //! Suggests shortening `Foo { field: field }` to `Foo { field }` in both
 //! expressions and patterns.
 
-use base_db::FileId;
+use ide_db::base_db::FileId;
 use ide_db::source_change::SourceFileEdit;
 use syntax::{ast, match_ast, AstNode, SyntaxNode};
 use text_edit::TextEdit;
diff --git a/crates/ide/src/diagnostics/fixes.rs b/crates/ide/src/diagnostics/fixes.rs
index 0c75e50b0..0c950003e 100644
--- a/crates/ide/src/diagnostics/fixes.rs
+++ b/crates/ide/src/diagnostics/fixes.rs
@@ -1,6 +1,5 @@
 //! Provides a way to attach fixes to the diagnostics.
 //! The same module also has all curret custom fixes for the diagnostics implemented.
-use base_db::FileId;
 use hir::{
     db::AstDatabase,
     diagnostics::{
@@ -9,6 +8,7 @@ use hir::{
     },
     HasSource, HirDisplay, Semantics, VariantDef,
 };
+use ide_db::base_db::FileId;
 use ide_db::{
     source_change::{FileSystemEdit, SourceFileEdit},
     RootDatabase,
diff --git a/crates/ide/src/display/navigation_target.rs b/crates/ide/src/display/navigation_target.rs
index cf9d617dc..0c429a262 100644
--- a/crates/ide/src/display/navigation_target.rs
+++ b/crates/ide/src/display/navigation_target.rs
@@ -1,8 +1,8 @@
 //! FIXME: write short doc here
 
-use base_db::{FileId, SourceDatabase};
 use either::Either;
 use hir::{original_range, AssocItem, FieldSource, HasSource, InFile, ModuleSource};
+use ide_db::base_db::{FileId, SourceDatabase};
 use ide_db::{defs::Definition, RootDatabase};
 use syntax::{
     ast::{self, DocCommentsOwner, NameOwner},
diff --git a/crates/ide/src/fixture.rs b/crates/ide/src/fixture.rs
index ed06689f0..eb57f9224 100644
--- a/crates/ide/src/fixture.rs
+++ b/crates/ide/src/fixture.rs
@@ -1,5 +1,5 @@
 //! Utilities for creating `Analysis` instances for tests.
-use base_db::fixture::ChangeFixture;
+use ide_db::base_db::fixture::ChangeFixture;
 use test_utils::{extract_annotations, RangeOrOffset};
 
 use crate::{Analysis, AnalysisHost, FileId, FilePosition, FileRange};
diff --git a/crates/ide/src/goto_definition.rs b/crates/ide/src/goto_definition.rs
index a87e31019..15792f947 100644
--- a/crates/ide/src/goto_definition.rs
+++ b/crates/ide/src/goto_definition.rs
@@ -100,7 +100,7 @@ pub(crate) fn reference_definition(
 
 #[cfg(test)]
 mod tests {
-    use base_db::FileRange;
+    use ide_db::base_db::FileRange;
     use syntax::{TextRange, TextSize};
 
     use crate::fixture;
diff --git a/crates/ide/src/goto_implementation.rs b/crates/ide/src/goto_implementation.rs
index 6c586bbd1..529004878 100644
--- a/crates/ide/src/goto_implementation.rs
+++ b/crates/ide/src/goto_implementation.rs
@@ -74,7 +74,7 @@ fn impls_for_trait(
 
 #[cfg(test)]
 mod tests {
-    use base_db::FileRange;
+    use ide_db::base_db::FileRange;
 
     use crate::fixture;
 
diff --git a/crates/ide/src/goto_type_definition.rs b/crates/ide/src/goto_type_definition.rs
index 6d0df04dd..aba6bf5dc 100644
--- a/crates/ide/src/goto_type_definition.rs
+++ b/crates/ide/src/goto_type_definition.rs
@@ -54,7 +54,7 @@ fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
 
 #[cfg(test)]
 mod tests {
-    use base_db::FileRange;
+    use ide_db::base_db::FileRange;
 
     use crate::fixture;
 
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
index 6466422c5..832192881 100644
--- a/crates/ide/src/hover.rs
+++ b/crates/ide/src/hover.rs
@@ -1,8 +1,8 @@
-use base_db::SourceDatabase;
 use hir::{
     Adt, AsAssocItem, AssocItemContainer, Documentation, FieldSource, HasSource, HirDisplay,
     Module, ModuleDef, ModuleSource, Semantics,
 };
+use ide_db::base_db::SourceDatabase;
 use ide_db::{
     defs::{Definition, NameClass, NameRefClass},
     RootDatabase,
@@ -385,8 +385,8 @@ fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
 
 #[cfg(test)]
 mod tests {
-    use base_db::FileLoader;
     use expect_test::{expect, Expect};
+    use ide_db::base_db::FileLoader;
 
     use crate::fixture;
 
@@ -638,6 +638,33 @@ fn main() { }
     }
 
     #[test]
+    fn hover_shows_fn_doc_attr_raw_string() {
+        check(
+            r##"
+#[doc = r#"Raw string doc attr"#]
+pub fn foo<|>(_: &Path) {}
+
+fn main() { }
+"##,
+            expect![[r##"
+                *foo*
+
+                ```rust
+                test
+                ```
+
+                ```rust
+                pub fn foo(_: &Path)
+                ```
+
+                ---
+
+                Raw string doc attr
+            "##]],
+        );
+    }
+
+    #[test]
     fn hover_shows_struct_field_info() {
         // Hovering over the field when instantiating
         check(
@@ -2128,7 +2155,7 @@ fn foo_<|>test() {}
                                     ignore: false,
                                 },
                             },
-                            cfg_exprs: [],
+                            cfg: None,
                         },
                     ),
                 ]
@@ -2166,7 +2193,7 @@ mod tests<|> {
                             kind: TestMod {
                                 path: "tests",
                             },
-                            cfg_exprs: [],
+                            cfg: None,
                         },
                     ),
                 ]
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index cecfae4c7..4bc733b70 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -48,11 +48,11 @@ mod doc_links;
 
 use std::sync::Arc;
 
-use base_db::{
+use cfg::CfgOptions;
+use ide_db::base_db::{
     salsa::{self, ParallelDatabase},
     CheckCanceled, Env, FileLoader, FileSet, SourceDatabase, VfsPath,
 };
-use cfg::CfgOptions;
 use ide_db::{
     symbol_index::{self, FileSymbol},
     LineIndexDatabase,
@@ -80,19 +80,19 @@ pub use crate::{
         Highlight, HighlightModifier, HighlightModifiers, HighlightTag, HighlightedRange,
     },
 };
-pub use call_info::CallInfo;
 pub use completion::{
     CompletionConfig, CompletionItem, CompletionItemKind, CompletionScore, InsertTextFormat,
 };
+pub use ide_db::call_info::CallInfo;
 
 pub use assists::{
     utils::MergeBehaviour, Assist, AssistConfig, AssistId, AssistKind, ResolvedAssist,
 };
-pub use base_db::{
+pub use hir::{Documentation, Semantics};
+pub use ide_db::base_db::{
     Canceled, Change, CrateGraph, CrateId, Edition, FileId, FilePosition, FileRange, SourceRoot,
     SourceRootId,
 };
-pub use hir::{Documentation, Semantics};
 pub use ide_db::{
     label::Label,
     line_index::{LineCol, LineIndex},
@@ -396,7 +396,7 @@ impl Analysis {
 
     /// Computes parameter information for the given call expression.
     pub fn call_info(&self, position: FilePosition) -> Cancelable<Option<CallInfo>> {
-        self.with_db(|db| call_info::call_info(db, position))
+        self.with_db(|db| ide_db::call_info::call_info(db, position))
     }
 
     /// Computes call hierarchy candidates for the given file position.
diff --git a/crates/ide/src/parent_module.rs b/crates/ide/src/parent_module.rs
index ef94acfec..6cc3b2991 100644
--- a/crates/ide/src/parent_module.rs
+++ b/crates/ide/src/parent_module.rs
@@ -1,5 +1,5 @@
-use base_db::{CrateId, FileId, FilePosition};
 use hir::Semantics;
+use ide_db::base_db::{CrateId, FileId, FilePosition};
 use ide_db::RootDatabase;
 use syntax::{
     algo::find_node_at_offset,
diff --git a/crates/ide/src/prime_caches.rs b/crates/ide/src/prime_caches.rs
index 6944dbcd2..ea0acfaa0 100644
--- a/crates/ide/src/prime_caches.rs
+++ b/crates/ide/src/prime_caches.rs
@@ -3,8 +3,8 @@
 //! request takes longer to compute. This modules implemented prepopulating of
 //! various caches, it's not really advanced at the moment.
 
-use base_db::SourceDatabase;
 use hir::db::DefDatabase;
+use ide_db::base_db::SourceDatabase;
 
 use crate::RootDatabase;
 
diff --git a/crates/ide/src/references.rs b/crates/ide/src/references.rs
index 67ec257a8..a517081d5 100644
--- a/crates/ide/src/references.rs
+++ b/crates/ide/src/references.rs
@@ -191,8 +191,8 @@ fn get_struct_def_name_for_struct_literal_search(
 
 #[cfg(test)]
 mod tests {
-    use base_db::FileId;
     use expect_test::{expect, Expect};
+    use ide_db::base_db::FileId;
     use stdx::format_to;
 
     use crate::{fixture, SearchScope};
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
index 35aafc49d..26ac2371a 100644
--- a/crates/ide/src/references/rename.rs
+++ b/crates/ide/src/references/rename.rs
@@ -1,7 +1,7 @@
 //! FIXME: write short doc here
 
-use base_db::SourceDatabaseExt;
 use hir::{Module, ModuleDef, ModuleSource, Semantics};
+use ide_db::base_db::SourceDatabaseExt;
 use ide_db::{
     defs::{Definition, NameClass, NameRefClass},
     RootDatabase,
diff --git a/crates/ide/src/runnables.rs b/crates/ide/src/runnables.rs
index 752ef2f21..eb82456ad 100644
--- a/crates/ide/src/runnables.rs
+++ b/crates/ide/src/runnables.rs
@@ -15,7 +15,7 @@ use crate::{display::ToNav, FileId, NavigationTarget};
 pub struct Runnable {
     pub nav: NavigationTarget,
     pub kind: RunnableKind,
-    pub cfg_exprs: Vec<CfgExpr>,
+    pub cfg: Option<CfgExpr>,
 }
 
 #[derive(Debug, Clone)]
@@ -168,7 +168,7 @@ fn runnable_fn(
     };
 
     let attrs = Attrs::from_attrs_owner(sema.db, InFile::new(HirFileId::from(file_id), &fn_def));
-    let cfg_exprs = attrs.cfg().collect();
+    let cfg = attrs.cfg();
 
     let nav = if let RunnableKind::DocTest { .. } = kind {
         NavigationTarget::from_doc_commented(
@@ -179,7 +179,7 @@ fn runnable_fn(
     } else {
         NavigationTarget::from_named(sema.db, InFile::new(file_id.into(), &fn_def))
     };
-    Some(Runnable { nav, kind, cfg_exprs })
+    Some(Runnable { nav, kind, cfg })
 }
 
 #[derive(Debug, Copy, Clone)]
@@ -255,9 +255,9 @@ fn runnable_mod(
         .join("::");
 
     let attrs = Attrs::from_attrs_owner(sema.db, InFile::new(HirFileId::from(file_id), &module));
-    let cfg_exprs = attrs.cfg().collect();
+    let cfg = attrs.cfg();
     let nav = module_def.to_nav(sema.db);
-    Some(Runnable { nav, kind: RunnableKind::TestMod { path }, cfg_exprs })
+    Some(Runnable { nav, kind: RunnableKind::TestMod { path }, cfg })
 }
 
 // We could create runnables for modules with number_of_test_submodules > 0,
@@ -348,7 +348,7 @@ fn bench() {}
                             docs: None,
                         },
                         kind: Bin,
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -373,7 +373,7 @@ fn bench() {}
                                 ignore: false,
                             },
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -398,7 +398,7 @@ fn bench() {}
                                 ignore: true,
                             },
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -420,7 +420,7 @@ fn bench() {}
                                 "bench",
                             ),
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                 ]
             "#]],
@@ -507,7 +507,7 @@ fn should_have_no_runnable_6() {}
                             docs: None,
                         },
                         kind: Bin,
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -527,7 +527,7 @@ fn should_have_no_runnable_6() {}
                                 "should_have_runnable",
                             ),
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -547,7 +547,7 @@ fn should_have_no_runnable_6() {}
                                 "should_have_runnable_1",
                             ),
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -567,7 +567,7 @@ fn should_have_no_runnable_6() {}
                                 "should_have_runnable_2",
                             ),
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                 ]
             "#]],
@@ -609,7 +609,7 @@ impl Data {
                             docs: None,
                         },
                         kind: Bin,
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -629,7 +629,7 @@ impl Data {
                                 "Data::foo",
                             ),
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                 ]
             "#]],
@@ -668,7 +668,7 @@ mod test_mod {
                         kind: TestMod {
                             path: "test_mod",
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -693,7 +693,7 @@ mod test_mod {
                                 ignore: false,
                             },
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                 ]
             "#]],
@@ -748,7 +748,7 @@ mod root_tests {
                         kind: TestMod {
                             path: "root_tests::nested_tests_0",
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -768,7 +768,7 @@ mod root_tests {
                         kind: TestMod {
                             path: "root_tests::nested_tests_0::nested_tests_1",
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -793,7 +793,7 @@ mod root_tests {
                                 ignore: false,
                             },
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -818,7 +818,7 @@ mod root_tests {
                                 ignore: false,
                             },
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -838,7 +838,7 @@ mod root_tests {
                         kind: TestMod {
                             path: "root_tests::nested_tests_0::nested_tests_2",
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                     Runnable {
                         nav: NavigationTarget {
@@ -863,7 +863,7 @@ mod root_tests {
                                 ignore: false,
                             },
                         },
-                        cfg_exprs: [],
+                        cfg: None,
                     },
                 ]
             "#]],
@@ -906,12 +906,14 @@ fn test_foo1() {}
                                 ignore: false,
                             },
                         },
-                        cfg_exprs: [
-                            KeyValue {
-                                key: "feature",
-                                value: "foo",
-                            },
-                        ],
+                        cfg: Some(
+                            Atom(
+                                KeyValue {
+                                    key: "feature",
+                                    value: "foo",
+                                },
+                            ),
+                        ),
                     },
                 ]
             "#]],
@@ -954,20 +956,24 @@ fn test_foo1() {}
                                 ignore: false,
                             },
                         },
-                        cfg_exprs: [
+                        cfg: Some(
                             All(
                                 [
-                                    KeyValue {
-                                        key: "feature",
-                                        value: "foo",
-                                    },
-                                    KeyValue {
-                                        key: "feature",
-                                        value: "bar",
-                                    },
+                                    Atom(
+                                        KeyValue {
+                                            key: "feature",
+                                            value: "foo",
+                                        },
+                                    ),
+                                    Atom(
+                                        KeyValue {
+                                            key: "feature",
+                                            value: "bar",
+                                        },
+                                    ),
                                 ],
                             ),
-                        ],
+                        ),
                     },
                 ]
             "#]],
diff --git a/crates/ide/src/status.rs b/crates/ide/src/status.rs
index 0af84daa0..8e91c99d7 100644
--- a/crates/ide/src/status.rs
+++ b/crates/ide/src/status.rs
@@ -1,10 +1,10 @@
 use std::{fmt, iter::FromIterator, sync::Arc};
 
-use base_db::{
+use hir::MacroFile;
+use ide_db::base_db::{
     salsa::debug::{DebugQueryTable, TableEntry},
     CrateId, FileId, FileTextQuery, SourceDatabase, SourceRootId,
 };
-use hir::MacroFile;
 use ide_db::{
     symbol_index::{LibrarySymbolsQuery, SymbolIndex},
     RootDatabase,
@@ -16,7 +16,7 @@ use stdx::format_to;
 use syntax::{ast, Parse, SyntaxNode};
 
 fn syntax_tree_stats(db: &RootDatabase) -> SyntaxTreeStats {
-    base_db::ParseQuery.in_db(db).entries::<SyntaxTreeStats>()
+    ide_db::base_db::ParseQuery.in_db(db).entries::<SyntaxTreeStats>()
 }
 fn macro_syntax_tree_stats(db: &RootDatabase) -> SyntaxTreeStats {
     hir::db::ParseMacroQuery.in_db(db).entries::<SyntaxTreeStats>()
diff --git a/crates/ide/src/syntax_highlighting.rs b/crates/ide/src/syntax_highlighting.rs
index b35c03162..9f864179e 100644
--- a/crates/ide/src/syntax_highlighting.rs
+++ b/crates/ide/src/syntax_highlighting.rs
@@ -579,7 +579,14 @@ fn highlight_element(
                 }
             }
             T![-] if element.parent().and_then(ast::PrefixExpr::cast).is_some() => {
-                HighlightTag::NumericLiteral.into()
+                let prefix_expr = element.parent().and_then(ast::PrefixExpr::cast)?;
+
+                let expr = prefix_expr.expr()?;
+                match expr {
+                    ast::Expr::Literal(_) => HighlightTag::NumericLiteral,
+                    _ => HighlightTag::Operator,
+                }
+                .into()
             }
             _ if element.parent().and_then(ast::PrefixExpr::cast).is_some() => {
                 HighlightTag::Operator.into()
@@ -763,6 +770,9 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
             if local.is_mut(db) || local.ty(db).is_mutable_reference() {
                 h |= HighlightModifier::Mutable;
             }
+            if local.ty(db).as_callable(db).is_some() || local.ty(db).impls_fnonce(db) {
+                h |= HighlightModifier::Callable;
+            }
             return h;
         }
     }
diff --git a/crates/ide/src/syntax_highlighting/html.rs b/crates/ide/src/syntax_highlighting/html.rs
index 57e2d2923..abcc5cccc 100644
--- a/crates/ide/src/syntax_highlighting/html.rs
+++ b/crates/ide/src/syntax_highlighting/html.rs
@@ -1,6 +1,6 @@
 //! Renders a bit of code as HTML.
 
-use base_db::SourceDatabase;
+use ide_db::base_db::SourceDatabase;
 use oorandom::Rand32;
 use stdx::format_to;
 use syntax::{AstNode, TextRange, TextSize};
diff --git a/crates/ide/src/syntax_highlighting/injection.rs b/crates/ide/src/syntax_highlighting/injection.rs
index acd91b26c..59a74bc02 100644
--- a/crates/ide/src/syntax_highlighting/injection.rs
+++ b/crates/ide/src/syntax_highlighting/injection.rs
@@ -3,8 +3,8 @@
 use std::{collections::BTreeMap, convert::TryFrom};
 
 use ast::{HasQuotes, HasStringValue};
-use call_info::ActiveParameter;
 use hir::Semantics;
+use ide_db::call_info::ActiveParameter;
 use itertools::Itertools;
 use syntax::{ast, AstToken, SyntaxNode, SyntaxToken, TextRange, TextSize};
 
diff --git a/crates/ide/src/syntax_highlighting/tags.rs b/crates/ide/src/syntax_highlighting/tags.rs
index c1b817f06..e8f78ad52 100644
--- a/crates/ide/src/syntax_highlighting/tags.rs
+++ b/crates/ide/src/syntax_highlighting/tags.rs
@@ -64,6 +64,7 @@ pub enum HighlightModifier {
     Mutable,
     Consuming,
     Unsafe,
+    Callable,
 }
 
 impl HighlightTag {
@@ -122,6 +123,7 @@ impl HighlightModifier {
         HighlightModifier::Mutable,
         HighlightModifier::Consuming,
         HighlightModifier::Unsafe,
+        HighlightModifier::Callable,
     ];
 
     fn as_str(self) -> &'static str {
@@ -134,6 +136,7 @@ impl HighlightModifier {
             HighlightModifier::Mutable => "mutable",
             HighlightModifier::Consuming => "consuming",
             HighlightModifier::Unsafe => "unsafe",
+            HighlightModifier::Callable => "callable",
         }
     }
 
diff --git a/crates/ide/src/syntax_highlighting/test_data/highlighting.html b/crates/ide/src/syntax_highlighting/test_data/highlighting.html
index 0bb0928e4..c6b4f5a00 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlighting.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlighting.html
@@ -44,6 +44,17 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="keyword">pub</span> <span class="keyword">trait</span> <span class="trait declaration">Copy</span> <span class="punctuation">{</span><span class="punctuation">}</span>
 <span class="punctuation">}</span>
 
+<span class="keyword">pub</span> <span class="keyword">mod</span> <span class="module declaration">ops</span> <span class="punctuation">{</span>
+    <span class="attribute">#</span><span class="attribute">[</span><span class="function attribute">lang</span><span class="attribute"> </span><span class="operator">=</span><span class="attribute"> </span><span class="string_literal">"fn_once"</span><span class="attribute">]</span>
+    <span class="keyword">pub</span> <span class="keyword">trait</span> <span class="trait declaration">FnOnce</span><span class="punctuation">&lt;</span><span class="type_param declaration">Args</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span><span class="punctuation">}</span>
+
+    <span class="attribute">#</span><span class="attribute">[</span><span class="function attribute">lang</span><span class="attribute"> </span><span class="operator">=</span><span class="attribute"> </span><span class="string_literal">"fn_mut"</span><span class="attribute">]</span>
+    <span class="keyword">pub</span> <span class="keyword">trait</span> <span class="trait declaration">FnMut</span><span class="punctuation">&lt;</span><span class="type_param declaration">Args</span><span class="punctuation">&gt;</span><span class="punctuation">:</span> <span class="trait">FnOnce</span><span class="punctuation">&lt;</span><span class="type_param">Args</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span><span class="punctuation">}</span>
+
+    <span class="attribute">#</span><span class="attribute">[</span><span class="function attribute">lang</span><span class="attribute"> </span><span class="operator">=</span><span class="attribute"> </span><span class="string_literal">"fn"</span><span class="attribute">]</span>
+    <span class="keyword">pub</span> <span class="keyword">trait</span> <span class="trait declaration">Fn</span><span class="punctuation">&lt;</span><span class="type_param declaration">Args</span><span class="punctuation">&gt;</span><span class="punctuation">:</span> <span class="trait">FnMut</span><span class="punctuation">&lt;</span><span class="type_param">Args</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span><span class="punctuation">}</span>
+<span class="punctuation">}</span>
+
 
 <span class="keyword">struct</span> <span class="struct declaration">Foo</span> <span class="punctuation">{</span>
     <span class="keyword">pub</span> <span class="field declaration">x</span><span class="punctuation">:</span> <span class="builtin_type">i32</span><span class="punctuation">,</span>
@@ -99,6 +110,11 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="function">foo</span><span class="operator">::</span><span class="punctuation">&lt;</span><span class="lifetime">'a</span><span class="punctuation">,</span> <span class="builtin_type">i32</span><span class="punctuation">&gt;</span><span class="punctuation">(</span><span class="punctuation">)</span>
 <span class="punctuation">}</span>
 
+<span class="keyword">use</span> <span class="module">ops</span><span class="operator">::</span><span class="trait">Fn</span><span class="punctuation">;</span>
+<span class="keyword">fn</span> <span class="function declaration">baz</span><span class="punctuation">&lt;</span><span class="type_param declaration">F</span><span class="punctuation">:</span> <span class="trait">Fn</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="operator">-&gt;</span> <span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">&gt;</span><span class="punctuation">(</span><span class="value_param declaration callable">f</span><span class="punctuation">:</span> <span class="type_param">F</span><span class="punctuation">)</span> <span class="punctuation">{</span>
+    <span class="value_param callable">f</span><span class="punctuation">(</span><span class="punctuation">)</span>
+<span class="punctuation">}</span>
+
 <span class="macro">macro_rules!</span> <span class="macro declaration">def_fn</span> <span class="punctuation">{</span>
     <span class="punctuation">(</span><span class="punctuation">$</span><span class="punctuation">(</span><span class="punctuation">$</span>tt<span class="punctuation">:</span>tt<span class="punctuation">)</span><span class="punctuation">*</span><span class="punctuation">)</span> <span class="operator">=</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span><span class="punctuation">$</span><span class="punctuation">(</span><span class="punctuation">$</span>tt<span class="punctuation">)</span><span class="punctuation">*</span><span class="punctuation">}</span>
 <span class="punctuation">}</span>
@@ -157,6 +173,12 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="variable mutable">copy</span><span class="punctuation">.</span><span class="function">quop</span><span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">;</span>
     <span class="variable mutable">copy</span><span class="punctuation">.</span><span class="function mutable">qux</span><span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">;</span>
     <span class="variable mutable">copy</span><span class="punctuation">.</span><span class="function">baz</span><span class="punctuation">(</span><span class="variable mutable">copy</span><span class="punctuation">)</span><span class="punctuation">;</span>
+
+    <span class="keyword">let</span> <span class="variable declaration callable">a</span> <span class="operator">=</span> <span class="punctuation">|</span><span class="value_param declaration">x</span><span class="punctuation">|</span> <span class="value_param">x</span><span class="punctuation">;</span>
+    <span class="keyword">let</span> <span class="variable declaration callable">bar</span> <span class="operator">=</span> <span class="struct">Foo</span><span class="operator">::</span><span class="function">baz</span><span class="punctuation">;</span>
+
+    <span class="keyword">let</span> <span class="variable declaration">baz</span> <span class="operator">=</span> <span class="numeric_literal">-</span><span class="numeric_literal">42</span><span class="punctuation">;</span>
+    <span class="keyword">let</span> <span class="variable declaration">baz</span> <span class="operator">=</span> <span class="operator">-</span><span class="variable">baz</span><span class="punctuation">;</span>
 <span class="punctuation">}</span>
 
 <span class="keyword">enum</span> <span class="enum declaration">Option</span><span class="punctuation">&lt;</span><span class="type_param declaration">T</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span>
diff --git a/crates/ide/src/syntax_highlighting/tests.rs b/crates/ide/src/syntax_highlighting/tests.rs
index 126363b8b..dd43f9dd9 100644
--- a/crates/ide/src/syntax_highlighting/tests.rs
+++ b/crates/ide/src/syntax_highlighting/tests.rs
@@ -18,6 +18,17 @@ pub mod marker {
     pub trait Copy {}
 }
 
+pub mod ops {
+    #[lang = "fn_once"]
+    pub trait FnOnce<Args> {}
+
+    #[lang = "fn_mut"]
+    pub trait FnMut<Args>: FnOnce<Args> {}
+
+    #[lang = "fn"]
+    pub trait Fn<Args>: FnMut<Args> {}
+}
+
 
 struct Foo {
     pub x: i32,
@@ -73,6 +84,11 @@ fn foo<'a, T>() -> T {
     foo::<'a, i32>()
 }
 
+use ops::Fn;
+fn baz<F: Fn() -> ()>(f: F) {
+    f()
+}
+
 macro_rules! def_fn {
     ($($tt:tt)*) => {$($tt)*}
 }
@@ -131,6 +147,12 @@ fn main() {
     copy.quop();
     copy.qux();
     copy.baz(copy);
+
+    let a = |x| x;
+    let bar = Foo::baz;
+
+    let baz = -42;
+    let baz = -baz;
 }
 
 enum Option<T> {
diff --git a/crates/ide/src/syntax_tree.rs b/crates/ide/src/syntax_tree.rs
index 0eed2dbd7..7941610d6 100644
--- a/crates/ide/src/syntax_tree.rs
+++ b/crates/ide/src/syntax_tree.rs
@@ -1,4 +1,4 @@
-use base_db::{FileId, SourceDatabase};
+use ide_db::base_db::{FileId, SourceDatabase};
 use ide_db::RootDatabase;
 use syntax::{
     algo, AstNode, NodeOrToken, SourceFile,
diff --git a/crates/ide/src/typing.rs b/crates/ide/src/typing.rs
index 94b91f049..43458a3a2 100644
--- a/crates/ide/src/typing.rs
+++ b/crates/ide/src/typing.rs
@@ -15,7 +15,7 @@
 
 mod on_enter;
 
-use base_db::{FilePosition, SourceDatabase};
+use ide_db::base_db::{FilePosition, SourceDatabase};
 use ide_db::{source_change::SourceFileEdit, RootDatabase};
 use syntax::{
     algo::find_node_at_offset,
diff --git a/crates/ide/src/typing/on_enter.rs b/crates/ide/src/typing/on_enter.rs
index 98adef1d6..f4ea30352 100644
--- a/crates/ide/src/typing/on_enter.rs
+++ b/crates/ide/src/typing/on_enter.rs
@@ -1,7 +1,7 @@
 //! Handles the `Enter` key press. At the momently, this only continues
 //! comments, but should handle indent some time in the future as well.
 
-use base_db::{FilePosition, SourceDatabase};
+use ide_db::base_db::{FilePosition, SourceDatabase};
 use ide_db::RootDatabase;
 use syntax::{
     ast::{self, AstToken},