queries(rust): add highlight query.

Also slightly changes the way constructors are highlighted.

lua/nvim-treesitter/highlight.lua

@@ -34,7 +34,7 @@ hlmap["parameter"] = "Identifier"
 hlmap["method"] = "Function"
 hlmap["field"] = "Identifier"
 hlmap["property"] = "Identifier"
-hlmap["constructor"] = "Special"
+hlmap["constructor"] = "Constant"
 
 -- Keywords
 hlmap["conditional"] = "Conditional"

queries/rust/highlights.scm

@@ -0,0 +1,139 @@
+; Forked from https://github.com/tree-sitter/tree-sitter-rust
+; Copyright (c) 2017 Maxim Sokolov
+; Licensed under the MIT license.
+
+; Identifier conventions
+
+; Assume all-caps names are constants
+((identifier) @constant
+ (match? @constant "^[A-Z][A-Z\\d_]+$'"))
+
+
+; Function calls
+(call_expression
+  function: (identifier) @function)
+(call_expression
+  function: (field_expression
+    field: (field_identifier) @method))
+(call_expression
+  function: (scoped_identifier
+    "::"
+    name: (identifier) @function))
+
+(generic_function
+  function: (identifier) @function)
+(generic_function
+  function: (scoped_identifier
+    name: (identifier) @function))
+(generic_function
+  function: (field_expression
+    field: (field_identifier) @method))
+
+; Assume other uppercase names are enum constructors
+((identifier) @constructor
+ (match? @constructor "^[A-Z]"))
+
+; Assume that uppercase names in paths are types
+((scoped_identifier
+  path: (identifier) @type)
+ (match? @type "^[A-Z]"))
+((scoped_identifier
+    name: (identifier) @type)
+ (match? @type "^[A-Z]"))
+
+(macro_invocation
+  macro: (identifier) @function.macro
+  "!" @function.macro)
+
+; Function definitions
+
+(function_item (identifier) @function)
+(function_signature_item (identifier) @function)
+
+; Other identifiers
+
+(type_identifier) @type
+(primitive_type) @type.builtin
+(field_identifier) @field
+
+(line_comment) @comment
+(block_comment) @comment
+
+"(" @punctuation.bracket
+")" @punctuation.bracket
+"[" @punctuation.bracket
+"]" @punctuation.bracket
+
+(type_arguments
+  "<" @punctuation.bracket
+  ">" @punctuation.bracket)
+(type_parameters
+  "<" @punctuation.bracket
+  ">" @punctuation.bracket)
+
+"::" @punctuation.delimiter
+"." @punctuation.delimiter
+";" @punctuation.delimiter
+
+(parameter (identifier) @parameter)
+
+(lifetime (identifier) @label)
+
+"break" @keyword
+"const" @keyword
+"continue" @conditional
+"default" @keyword
+"dyn" @keyword
+"else" @conditional
+"enum" @keyword
+"extern" @keyword
+"fn" @keyword
+"for" @repeat
+"if" @conditional
+"impl" @keyword
+"in" @repeat
+"let" @keyword
+"loop" @repeat
+"macro_rules!" @keyword
+"match" @keyword
+"mod" @keyword
+"move" @keyword
+"pub" @keyword
+"ref" @keyword
+"return" @keyword
+"static" @keyword
+"struct" @structure
+"trait" @keyword
+"type" @keyword
+"union" @keyword
+"unsafe" @keyword
+"use" @keyword
+"where" @keyword
+"while" @repeat
+(mutable_specifier) @keyword
+(use_list (self) @keyword)
+(scoped_use_list (self) @keyword)
+(scoped_identifier (self) @keyword)
+(super) @keyword
+
+(self) @variable.builtin
+
+(char_literal) @string
+(string_literal) @string
+(raw_string_literal) @string
+
+(boolean_literal) @boolean
+(integer_literal) @number
+(float_literal) @float
+
+(escape_sequence) @string.escape
+
+; TODO(vigoux): attribute items should have some kind of injections
+(attribute_item) @keyword
+(inner_attribute_item) @keyword
+
+"as" @operator
+"*" @operator
+"&" @operator
+"'" @operator
+(closure_parameters "|" @operator "|" @operator)