nvim-treesitter/queries/ruby/highlights.scm

; Variables
[
  (identifier)
  (global_variable)
] @variable

; Keywords
[
  "alias"
  "begin"
  "do"
  "end"
  "ensure"
  "module"
  "rescue"
  "then"
] @keyword

"class" @keyword.type

[
  "return"
  "yield"
] @keyword.return

[
  "and"
  "or"
  "in"
  "not"
] @keyword.operator

[
  "def"
  "undef"
] @keyword.function

(method
  "end" @keyword.function)

[
  "case"
  "else"
  "elsif"
  "if"
  "unless"
  "when"
  "then"
] @keyword.conditional

(if
  "end" @keyword.conditional)

[
  "for"
  "until"
  "while"
  "break"
  "redo"
  "retry"
  "next"
] @keyword.repeat

(constant) @constant

((identifier) @keyword.modifier
  (#any-of? @keyword.modifier "private" "protected" "public"))

[
  "rescue"
  "ensure"
] @keyword.exception

; Function calls
"defined?" @function

(call
  receiver: (constant)? @type
  method: [
    (identifier)
    (constant)
  ] @function.call)

(program
  (call
    (identifier) @keyword.import)
  (#any-of? @keyword.import "require" "require_relative" "load"))

; Function definitions
(alias
  (identifier) @function)

(setter
  (identifier) @function)

(method
  name: [
    (identifier) @function
    (constant) @type
  ])

(singleton_method
  name: [
    (identifier) @function
    (constant) @type
  ])

(class
  name: (constant) @type)

(module
  name: (constant) @type)

(superclass
  (constant) @type)

; Identifiers
[
  (class_variable)
  (instance_variable)
] @variable.member

((identifier) @constant.builtin
  (#any-of? @constant.builtin
    "__callee__" "__dir__" "__id__" "__method__" "__send__" "__ENCODING__" "__FILE__" "__LINE__"))

((identifier) @function.builtin
  (#any-of? @function.builtin "attr_reader" "attr_writer" "attr_accessor" "module_function"))

((call
  !receiver
  method: (identifier) @function.builtin)
  (#any-of? @function.builtin "include" "extend" "prepend" "refine" "using"))

((identifier) @keyword.exception
  (#any-of? @keyword.exception "raise" "fail" "catch" "throw"))

((constant) @type
  (#not-lua-match? @type "^[A-Z0-9_]+$"))

[
  (self)
  (super)
] @variable.builtin

(method_parameters
  (identifier) @variable.parameter)

(lambda_parameters
  (identifier) @variable.parameter)

(block_parameters
  (identifier) @variable.parameter)

(splat_parameter
  (identifier) @variable.parameter)

(hash_splat_parameter
  (identifier) @variable.parameter)

(optional_parameter
  (identifier) @variable.parameter)

(destructured_parameter
  (identifier) @variable.parameter)

(block_parameter
  (identifier) @variable.parameter)

(keyword_parameter
  (identifier) @variable.parameter)

; TODO: Re-enable this once it is supported
; ((identifier) @function
;  (#is-not? local))
; Literals
[
  (string_content)
  (heredoc_content)
  "\""
  "`"
] @string

[
  (heredoc_beginning)
  (heredoc_end)
] @label

[
  (bare_symbol)
  (simple_symbol)
  (delimited_symbol)
  (hash_key_symbol)
] @string.special.symbol

(regex
  (string_content) @string.regexp)

(escape_sequence) @string.escape

(integer) @number

(float) @number.float

[
  (true)
  (false)
] @boolean

(nil) @constant.builtin

(comment) @comment @spell

((program
  .
  (comment) @keyword.directive @nospell)
  (#lua-match? @keyword.directive "^#!/"))

(program
  (comment)+ @comment.documentation
  (class))

(module
  (comment)+ @comment.documentation
  (body_statement
    (class)))

(class
  (comment)+ @comment.documentation
  (body_statement
    (method)))

(body_statement
  (comment)+ @comment.documentation
  (method))

; Operators
[
  "!"
  "="
  "=="
  "==="
  "<=>"
  "=>"
  "->"
  ">>"
  "<<"
  ">"
  "<"
  ">="
  "<="
  "**"
  "*"
  "/"
  "%"
  "+"
  "-"
  "&"
  "|"
  "^"
  "&&"
  "||"
  "||="
  "&&="
  "!="
  "%="
  "+="
  "-="
  "*="
  "/="
  "=~"
  "!~"
  "?"
  ":"
  ".."
  "..."
] @operator

[
  ","
  ";"
  "."
  "&."
  "::"
] @punctuation.delimiter

(regex
  "/" @punctuation.bracket)

(pair
  ":" @punctuation.delimiter)

[
  "("
  ")"
  "["
  "]"
  "{"
  "}"
  "%w("
  "%i("
] @punctuation.bracket

(block_parameters
  "|" @punctuation.bracket)

(interpolation
  "#{" @punctuation.special
  "}" @punctuation.special)