; TODO: automate highlighting testing
; TODO: ensure that name segments are highlighted correctly in each context

(comment) @comment.line
(integer) @constant.numeric
(string) @string.quoted
(escape_sequence) @constant.character.escape
(variable) @variable
(expr symbol: _ @constant)
(import (symbol) @module)
(type (name)) @type
(type_alias name: _ @type)

(rule relation: (name) @constructor)
(relation name: (symbol) @function)
(apply head: _ @function)

[ ":-" "," "." ":" ] @punctuation.delimiter
[ "(" ")" "{" "}" ] @punctuation.bracket

(aggregate_op) @keyword
(binary_expr op: _ @operator)
(unary_expr op: _ @operator)

[
  "type"
  "decision"
  "define"
  "import"
  "input"
  "output"
  "soft"
] @keyword

; doc comments
((comment)+ @comment.docs . (relation))
((comment)+ @comment.docs . (rule))
((comment)+ @comment.docs . (assumption))