[Rust] Support macro repetitions inside structs

This only addresses a specific case of macro repetitions inside the
struct body and similar changes to other statements with body blocks
are likely also necessary, but I'm keeping the change to a limited in
order to observe its effects first. Further reports of such issues can
be handled analogously.

Rust/Rust.sublime-syntax

@@ -35,8 +35,11 @@ contexts:
     # however then we run into infinite recursion. It needs to be a prototype
     # since macro_rules! allows constructing new code, thus the metavariables
     # can be inserted in just about any position in the syntax.
-    - match: '\${{identifier}}'
+    # See also: https://doc.rust-lang.org/reference/macros-by-example.html
+    - match: \${{identifier}}
       scope: variable.other.rust
+    - match: \$\(
+      scope: punctuation.section.interpolation.begin.rust
 
   statements:
     # This isn't really just "statements", it also includes all types,
@@ -818,21 +821,21 @@ contexts:
     - include: comments
     - include: attributes
     - include: visibility
-    - match: '{{identifier}}(?=\s*:)'
+    - match: '{{identifier}}'
       scope: variable.other.member.rust
+    - match: ':'
+      scope: punctuation.separator.rust
       push:
         - match: ','
           scope: punctuation.separator.rust
           pop: true
         - match: '(?=\})'
           pop: true
         - include: comments
-        - match: ':'
-          scope: punctuation.separator.rust
         - include: types
-    - match: '(?=\S)'
-      # Abort for an invalid match.
-      pop: true
+        - include: else-pop
+    # Abort for an invalid match.
+    - include: else-pop
 
   ##[ UNIONS ]#################################################################
 
@@ -1116,7 +1119,7 @@ contexts:
       pop: true
     - match: '\S'
       # This is intended to help make it evident when you forget a semicolon.
-      scope: invalid.illegal.rust
+      scope: invalid.illegal.expected-semi-colon.rust
 
   ##[ IMPL DEFINITIONS ]######################################################
 
@@ -1790,9 +1793,20 @@ contexts:
       scope: invalid.illegal.rust
 
   else-pop:
+    - include: macro-repetition-end
     - match: (?=\S)
       pop: true
 
   immediately-pop:
+    - include: macro-repetition-end
     - match: ''
       pop: true
+
+  macro-repetition-end:
+    # This is basically a prototype but needs to be appended to the end of a context.
+    # See also: https://doc.rust-lang.org/reference/macros-by-example.html#repetitions
+    - match: (\))([,;])?([*+?])
+      captures:
+        1: punctuation.section.interpolation.end.rust
+        2: punctuation.separator.rust
+        3: keyword.operator.other.repetition.rust

Rust/tests/syntax_test_macros.rs

@@ -384,3 +384,50 @@ macro_rules! designators {
 //                                                                    ^^ meta.macro meta.macro.transcribers
 }
 //<- meta.macro punctuation.section.block.end
+
+/*******************************************************************/
+// Nested multi-line statements
+macro_rules! test {
+    ($($name:ident),+$(,)?) => {
+        pub struct Foo {
+            $(
+//          ^^ meta.macro meta.macro.transcribers meta.struct meta.block punctuation.section.interpolation.begin.rust
+                pub $name : Option<String>
+//              ^^^^^^^^^^^^^^^^^^^^^^^^^^^ meta.macro meta.macro.transcribers meta.struct meta.block
+//              ^^^ storage.modifier.rust
+//                  ^^^^^ variable.other.rust
+//                        ^ punctuation.separator.rust
+//                          ^^^^^^ support.type.rust
+            ),+
+//          ^^^^ meta.macro meta.macro.transcribers meta.struct meta.block
+//          ^ punctuation.section.interpolation.end.rust
+//           ^ punctuation.separator.rust
+//            ^ keyword.operator.other.repetition.rust
+        }
+//      ^ meta.macro meta.macro.transcribers meta.struct meta.block punctuation.section.block.end.rust
+
+        pub async fn thing() -> () {}
+//      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ meta.macro meta.macro.transcribers
+//      ^^^ storage.modifier.rust
+//          ^^^^^ keyword.control.rust
+//                ^^ storage.type.function.rust
+//                   ^^^^^ entity.name.function.rust
+//                        ^^ meta.function meta.function.parameters
+//                           ^^^^^ meta.function meta.function.return-type
+//                           ^^ punctuation.separator.rust
+//                              ^^ meta.group
+//                                 ^^ meta.function meta.block
+    }
+//  ^ meta.macro meta.macro.transcribers punctuation.section.block.end.rust
+}
+// <- meta.macro punctuation.section.block.end.rust
+
+/*******************************************************************/
+// Not part of a macro
+some()?;
+//   ^ punctuation.section.group.end.rust
+//    ^ keyword.operator.rust
+
+(a)+(b);
+//^ punctuation.section.group.end.rust
+// ^ keyword.operator.arithmetic.rust