[Rust] Use keyword.declaration scope (#3911)

* [Rust] Use `keyword.declaration` scope

Following the example of Java, we're replacing the `storage.type` scope
with `keyword.declaration` without keeping the `storage.type` for
compatibility. Also, like in Java, the `use` keyword gets a
`keyword.declaration.import` scope to signal that it is introducing
names into the current namespace.

`type` aliases have slightly been refactored to properly match `where`
clauses. (I did a bit of work twice here because I forgot to `git pull`
before and included the remainder …)

* [Rust] Refine scopes of variable declaration keywords

* [Rust] Also match `macro_rules!` as a keyword

Rust/Rust.sublime-syntax

@@ -44,8 +44,7 @@ contexts:
 
     - include: visibility
 
-    - match: ';'
-      scope: punctuation.terminator.rust
+    - include: terminators
 
     - match: '(''(?:{{non_raw_ident}}))\s*(:)'
       captures:
@@ -112,13 +111,11 @@ contexts:
   modules:
     - match: '\b(mod)\s+({{identifier}})\b'
       captures:
-        1: storage.type.module.rust
+        1: keyword.declaration.module.rust
         2: entity.name.module.rust
       push:
         - meta_scope: meta.module.rust
-        - match: ';'
-          scope: punctuation.terminator.rust
-          pop: true
+        - include: terminator
         - include: module-block
 
   module-block:
@@ -133,32 +130,24 @@ contexts:
 
     - match: '\b(fn)\s+(?={{identifier}})'
       captures:
-        1: storage.type.function.rust
+        1: keyword.declaration.function.rust
       push: fn-definition
 
     - match: '\bstruct\b'
-      scope: storage.type.struct.rust
+      scope: keyword.declaration.struct.rust
       push: struct-identifier
 
     - match: '\bunion\b(?!\s*\()'
-      scope: storage.type.union.rust
+      scope: keyword.declaration.union.rust
       push: union-identifier
 
-    - match: '\b(type)\s+({{identifier}})\b'
-      captures:
-        1: storage.type.type.rust
-        2: entity.name.type.rust
-      push:
-        - match: (?=<)
-          push: generic-angles
-        - match: '=(?!=)'
-          scope: keyword.operator.assignment.rust
-          set: type-declaration-body
-        - include: else-pop
+    - match: '\btype\b'
+      scope: keyword.declaration.type.rust
+      push: type-declaration-identifier
 
     - match: '\b(trait)\s+({{identifier}})\b'
       captures:
-        1: storage.type.trait.rust
+        1: keyword.declaration.trait.rust
         2: entity.name.trait.rust
       push:
         - meta_scope: meta.trait.rust
@@ -171,11 +160,11 @@ contexts:
         - include: trait-block
 
     - match: '\bimpl\b'
-      scope: storage.type.impl.rust
+      scope: keyword.declaration.impl.rust
       push: impl-definition
 
     - match: '\benum\b'
-      scope: storage.type.enum.rust
+      scope: keyword.declaration.enum.rust
       push: enum-identifier
 
     - include: raw-pointer
@@ -187,20 +176,20 @@ contexts:
 
     - match: '\b(const)\s+({{identifier}})'
       captures:
-        1: storage.type.rust
+        1: keyword.declaration.variable.constant.rust
         2: entity.name.constant.rust
       push: declaration-after-identifier
 
     - match: '\b(static)\s+(?:(mut)\s+)?({{identifier}})'
       captures:
-        1: storage.type.rust
+        1: keyword.declaration.variable.static.rust
         2: storage.modifier.rust
         3: entity.name.constant.rust
       push: declaration-after-identifier
 
     - match: \b(let)\s+(?:(mut)\s+)?
       captures:
-        1: storage.type.rust
+        1: keyword.declaration.variable.rust
         2: storage.modifier.rust
       push: declaration-identifier
 
@@ -211,7 +200,7 @@ contexts:
 
     - match: '\b(macro_rules!)\s+({{identifier}})\b'
       captures:
-        1: support.function.rust
+        1: keyword.declaration.macro.rust
         2: entity.name.macro.rust
       push: macro-block
 
@@ -496,10 +485,6 @@ contexts:
 
   ##[ TYPES ]#################################################################
 
-  type-declaration-body:
-    - include: types
-    - include: else-pop
-
   types-relaxed:
     # only the most obvious type constructs (for fallback matching)
     - match: (?=[!?]\s*{{type_identifier}})
@@ -866,6 +851,31 @@ contexts:
     - meta_scope: meta.union.rust meta.block.rust
     - include: struct-classic-body
 
+  ##[ TYPE DECLARATIONS ]#####################################################
+
+  type-declaration-identifier:
+    - meta_scope: meta.type-declaration.rust
+    - include: comments
+    - include: type-declaration-wheres  # deprecated
+    - match: '{{identifier}}'
+      scope: entity.name.type.rust
+    - match: '(?=<)'
+      push: generic-angles
+    - match: '=(?!=)'
+      scope: keyword.operator.assignment.rust
+      set: type-declaration-body
+    - include: else-pop
+
+  type-declaration-body:
+    - meta_content_scope: meta.type-declaration.rust
+    - include: type-declaration-wheres
+    - include: types
+    - include: else-pop
+
+  type-declaration-wheres:
+    - match: '(?=\bwhere\b)'
+      push: impl-where
+
   ##[ ENUMS ]#################################################################
 
   enum-identifier:
@@ -1109,9 +1119,7 @@ contexts:
 
   macro-semi-sep:
     - include: comments
-    - match: ';'
-      scope: punctuation.terminator.rust
-      pop: true
+    - include: terminator
     - match: '(?=[})\]])'
       pop: true
     - match: '\S'
@@ -1171,7 +1179,7 @@ contexts:
   impl-where:
     - meta_scope: meta.where.rust
     - include: comments
-    - match: '(?=(\{|;))'
+    - match: '(?=(\{|;|=))'
       pop: true
     - match: \bwhere\b
       scope: keyword.other.rust
@@ -1731,40 +1739,51 @@ contexts:
       scope: storage.modifier.rust
 
   keywords:
-    # All keywords.  Note in `statements` some of these are superseded by more
+    # All keywords.  Note in `statements` most of these are superseded by more
     # specific rules.
     - include: bool
 
-    - match: \b(let|const|static)\b
-      scope: storage.type.rust
+    - match: \blet\b
+      scope: keyword.declaration.variable.rust
+
+    - match: \bstatic\b
+      scope: keyword.declaration.variable.static.rust
+
+    - match: \bconst\b
+      # The storage keyword seems more likely to not have been matched earlier.
+      scope: storage.modifier.rust
+      # scope: keyword.declaration.variable.constant.rust
 
     - match: \bfn\b
-      scope: storage.type.function.rust
+      scope: keyword.declaration.function.rust
 
     - match: \bmod\b
-      scope: storage.type.module.rust
+      scope: keyword.declaration.module.rust
 
     - match: \bstruct\b
-      scope: storage.type.struct.rust
+      scope: keyword.declaration.struct.rust
 
     - match: \bimpl\b
-      scope: storage.type.impl.rust
+      scope: keyword.declaration.impl.rust
 
     - match: \benum\b
-      scope: storage.type.enum.rust
+      scope: keyword.declaration.enum.rust
 
     - match: \btype\b
-      scope: storage.type.type.rust
+      scope: keyword.declaration.type.rust
 
     - match: \btrait\b
-      scope: storage.type.trait.rust
+      scope: keyword.declaration.trait.rust
 
     - match: \b(mut|pub|unsafe|move|ref)\b
       scope: storage.modifier.rust
 
-    - match: \b(crate|extern|use|where)\b
+    - match: \b(crate|extern|where)\b
       scope: keyword.other.rust
 
+    - match: \buse\b
+      scope: keyword.declaration.import.rust
+
     - match: \b(async|await|else|for|if|loop|match|try|while|yield)\b
       scope: keyword.control.rust
 
@@ -1789,6 +1808,15 @@ contexts:
     - match: \b(virtual|become|priv|typeof|unsized|do|abstract|final|override|macro|for)\b
       scope: invalid.illegal.rust
 
+  terminators:
+    - match: ';'
+      scope: punctuation.terminator.rust
+
+  terminator:
+    - match: ';'
+      scope: punctuation.terminator.rust
+      pop: true
+
   else-pop:
     - match: (?=\S)
       pop: true

Rust/tests/syntax_test_attributes.rs

@@ -38,7 +38,8 @@
 // Test highlighting/scope with struct field attributes
 // https://github.com/rust-lang/sublime-rust/issues/120
 pub struct Claim {
-//  ^^^^^^^^ meta.struct
+//  ^^^^^^^^^^^^^^^ meta.struct.rust
+//  ^^^^^^ keyword.declaration.struct.rust
     pub claim_id: String,
 //  ^^^ storage.modifier
     pub patient_id: String,
@@ -74,6 +75,7 @@ enum E {
 
 // Generic parameters.
 unsafe impl<#[may_dangle] T: ?Sized> Drop for Box<T> { }
+//     ^^^^ keyword.declaration.impl
 //          ^^^^^^^^^^^^^ meta.annotation
 //         ^^^^^^^^^^^^^^^^^^^^^^^^^ meta.impl meta.generic
 
@@ -120,7 +122,7 @@ unsafe impl<#[may_dangle] T: ?Sized> Drop for Box<T> { }
         true,
 //      ^^^^ constant.language
         struct,
-//      ^^^^^^ storage.type.struct
+//      ^^^^^^ keyword.declaration.struct
         1 + 1,
 //      ^ constant.numeric.integer.decimal
 //        ^ keyword.operator.arithmetic

Rust/tests/syntax_test_control_flow.rs

@@ -71,7 +71,7 @@ if n < 0 {
 // <- meta.block punctuation.section.block.end
 
 if let BasicStruct(i) = j {
-// ^^^ storage.type
+// ^^^ keyword.declaration.variable.rust
 //                    ^ keyword.operator.assignment
 //                        ^ meta.block punctuation.section.block.begin
     println!("Basic value: {}", i);
@@ -80,7 +80,7 @@ if let BasicStruct(i) = j {
 
 while let BasicStruct(k) = j {
 //^^^ keyword.control
-//    ^^^ storage.type
+//    ^^^ keyword.declaration.variable.rust
 //                       ^ keyword.operator.assignment
 //                           ^ meta.block punctuation.section.block.begin
     println!("Constructed example: {}", j)

Rust/tests/syntax_test_enum.rs

@@ -1,7 +1,7 @@
 // SYNTAX TEST "Packages/Rust/Rust.sublime-syntax"
 
 enum OperatingSystem
-// <- storage.type.enum
+// <- keyword.declaration.enum
 // ^^^^^^^^^^^^^^^^^ meta.enum
 //   ^^^^^^^^^^^^^^^ entity.name.enum
 {

Rust/tests/syntax_test_expr.rs

@@ -3,6 +3,9 @@
 // specific categories.
 
 let big_n =
+// <- keyword.declaration.variable.rust
+ // <- keyword.declaration.variable.rust
+//^ keyword.declaration.variable.rust
 //        ^ keyword.operator.assignment
     if n < 10 && n > -10 {
 //       ^ keyword.operator.comparison

Rust/tests/syntax_test_functions.rs

@@ -1,7 +1,7 @@
 // SYNTAX TEST "Packages/Rust/Rust.sublime-syntax"
 
 fn my_func(x: i32)
-// <- storage.type.function
+// <- keyword.declaration.function
 // ^^^^^^^ entity.name.function
 //        ^^^^^^^^ meta.function.parameters
 //        ^ punctuation.section.parameters.begin
@@ -15,7 +15,7 @@ fn my_func(x: i32)
 // <-  meta.function meta.block punctuation.section.block.end
 
 fn foo<A>(i: u32, b: i64) -> u32 {
-// <- storage.type.function
+// <- keyword.declaration.function
 // ^^^ entity.name.function
 //    ^ punctuation.definition.generic.begin
 //      ^ punctuation.definition.generic.end
@@ -47,7 +47,7 @@ fn my_other_func(e: OperatingSystem) -> &'a Type {
 
 pub fn pub_function() -> bool
 // <- storage.modifier
-//  ^^ storage.type.function
+//  ^^ keyword.declaration.function
 //     ^^^^^^^^^^^^ entity.name.function
 {
 // <- meta.function
@@ -61,7 +61,7 @@ pub unsafe extern "C" fn __sync_synchronize() { }
 //         ^^^^^^ keyword.other
 //                ^^^ string.quoted.double
 //                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^ meta.function
-//                    ^^ storage.type.function
+//                    ^^ keyword.declaration.function
 //                       ^^^^^^^^^^^^^^^^^^ entity.name.function
 //                                         ^ meta.function.parameters punctuation.section.parameters.begin
 //                                          ^ meta.function.parameters punctuation.section.parameters.end
@@ -117,20 +117,20 @@ fn f(self,
 
 const fn f() {}
 // <- storage.modifier
-//    ^^ meta.function storage.type.function
+//    ^^ meta.function keyword.declaration.function
 //       ^ meta.function entity.name.function
 
 const unsafe fn f() {}
 // <- storage.modifier
 //    ^^^^^^ storage.modifier
-//           ^^ meta.function storage.type.function
+//           ^^ meta.function keyword.declaration.function
 //              ^ meta.function entity.name.function
 
 const extern "C" fn f() {}
 // <- storage.modifier
 //    ^^^^^^ keyword.other
 //           ^^^ string.quoted.double
-//               ^^ meta.function storage.type.function
+//               ^^ meta.function keyword.declaration.function
 //                  ^ meta.function entity.name.function
 
 fn foo(&'a self) {}

Rust/tests/syntax_test_generics.rs

@@ -97,7 +97,7 @@ struct A<T>(T) where T: AsRef<str>;
 //             ^^^^^ meta.struct meta.where keyword.other
 pub struct A<T>(T)
 //  ^^^^^^^^^^ meta.struct
-//  ^^^^^^ meta.struct storage.type
+//  ^^^^^^ meta.struct keyword.declaration
 where
 //^^^ meta.struct meta.where keyword.other
     T: AsRef<str>;
@@ -342,7 +342,7 @@ fn f(a: for<'a, 'b> fn() -> String) {}
 
 // Function in type path with return type.
 fn factory() -> Box<Fn(i32) -> i32> {
-// <- storage.type.function
+// <- keyword.declaration.function
 // ^^^^^^^ entity.name.function
 //                 ^^^^^^^^^^^^^^^^ meta.generic
 //                  ^^ support.type