feat: Improved syntax highlighting for Gleam (#13807)

book/src/themes.md

@@ -174,6 +174,7 @@ We use a similar set of scopes as
     - `documentation` - Line documentation comments (e.g. `///` in Rust)
   - `block` - Block comments (e.g. (`/* */`)
     - `documentation` - Block documentation comments (e.g. `/** */` in Rust)
+  - `unused` - Unused variables and patterns, e.g. `_` and `_foo`
 
 - `variable` - Variables
   - `builtin` - Reserved language variables (`self`, `this`, `super`, etc.)

languages.toml

@@ -2080,14 +2080,14 @@ scope = "source.gleam"
 injection-regex = "gleam"
 file-types = ["gleam"]
 roots = ["gleam.toml"]
-comment-token = "//"
+comment-tokens = ["//", "///", "////"]
 indent = { tab-width = 2, unit = "  " }
 language-servers = [ "gleam" ]
 auto-format = true
 
 [[grammar]]
 name = "gleam"
-source = { git = "https://github.com/gleam-lang/tree-sitter-gleam", rev = "6ece453acf8b14568c10f629f8cd25d3dde3794f" }
+source = { git = "https://github.com/gleam-lang/tree-sitter-gleam", rev = "ee93c639dc82148d716919df336ad612fd33538e" }
 
 [[language]]
 name = "quarto"

runtime/queries/gleam/highlights.scm

@@ -1,11 +1,12 @@
 ; Variables
 (identifier) @variable
-(discard) @comment.unused
+(discard) @comment.unused ; `_` pattern
+(hole) @comment.unused ; `_`, `_foo` unused variable
 
 ; Comments
-(module_comment) @comment
-(statement_comment) @comment
-(comment) @comment
+(module_comment) @comment.line.documentation
+(statement_comment) @comment.line.documentation
+(comment) @comment.line
 
 ; Constants
 (constant
@@ -23,7 +24,10 @@
   field: (label) @function)
  (#is-not? local))
 
+; =========
 ; Functions
+; =========
+
 (unqualified_import (identifier) @function)
 (unqualified_import "type" (type_identifier) @type)
 (unqualified_import (type_identifier) @constructor)
@@ -41,6 +45,10 @@
    right: (identifier) @function)
  (#is-not? local))
 
+; =========
+; Misc
+; =========
+
 ; "Properties"
 ; Assumed to be intended to refer to a name for a field; something that comes
 ; before ":" or after "."
@@ -56,27 +64,55 @@
 
 (attribute_value (identifier) @constant)
 
+; =========
+; Types
+; =========
+
+(type_hole) @comment.unused
+
 ; Type names
 (remote_type_identifier) @type
 (type_identifier) @type
 
+; Generic types
+[
+  ; in `pub type Dict(key, value)` this is `key` and `value`
+  (type_parameter)
+  ; in `pub fn size(dict: Dict(key, value)) -> Int` this is `key` and `value`
+  (type_var)
+] @type
+
 ; Data constructors
 (constructor_name) @constructor
 
+; built-ins
+((constructor_name) @constant.builtin
+  (#any-of? @constant.builtin "False" "True"))
+((constructor_name) @constant.builtin
+  (#any-of? @constant.builtin "Nil"))
+((constructor_name) @type.enum.variant.builtin
+  (#any-of? @type.enum.variant.builtin "Ok" "Error" "Some" "None"))
+
+; =========
 ; Literals
+; =========
+
 (string) @string
+(escape_sequence) @constant.character.escape
 ((escape_sequence) @warning
  (#eq? @warning "\\e")) ; deprecated escape sequence
-(escape_sequence) @constant.character.escape
 (bit_string_segment_option) @function.builtin
 (integer) @constant.numeric.integer
 (float) @constant.numeric.float
 
 ; Reserved identifiers
 ((identifier) @error
- (#any-of? @error "auto" "delegate" "derive" "else" "implement" "macro" "test" "echo"))
+ (#any-of? @error "auto" "delegate" "derive" "else" "implement" "macro" "test"))
 
+; =========
 ; Keywords
+; =========
+
 [
   (visibility_modifier) ; "pub"
   (opacity_modifier) ; "opaque"
@@ -94,15 +130,32 @@
   "todo"
   "type"
   "use"
+  "echo"
 ] @keyword
 
+; =========
 ; Operators
+; =========
+
 (binary_expression
   operator: _ @operator)
 (boolean_negation "!" @operator)
 (integer_negation "-" @operator)
 
+[
+  "->"
+  "-"
+  "="
+  ".."
+  "<-"
+  ; OR clause in patterns
+  "|"
+] @operator
+
+; ==========
 ; Punctuation
+; ==========
+
 [
   "("
   ")"
@@ -113,15 +166,23 @@
   "<<"
   ">>"
 ] @punctuation.bracket
+
+(tuple_type "#" @punctuation.bracket)
+(tuple "#" @punctuation.bracket)
+(tuple_pattern "#" @punctuation.bracket)
+
+[
+  ","
+  ":"
+] @punctuation.delimiter
+
+; the `/` in `import gleam/list`
+(import (module "/" @punctuation.delimiter))
+
 [
   "."
-  ","
-  ;; Controversial -- maybe some are operators?
-  ":"
-  "#"
-  "="
-  "->"
-  ".."
-  "-"
-  "<-"
-] @punctuation.delimiter
+] @punctuation
+
+; affects e.g. `replace` in `string.replace("+", "-")`
+; without this, it would be highlighted as a field instead of function
+(function_call (field_access (label) @function))

runtime/queries/gleam/injections.scm

@@ -1,3 +1,7 @@
 ((comment) @injection.content
  (#set! injection.language "comment"))
 
+; Inject markdown into documentation comments
+((doc_comment_content) @injection.content
+ (#set! injection.language "markdown")
+ (#set! injection.combined))