grammar.js

const bindings = require("./grammar/term-");
const types = require("./grammar/types");
const useClause = require("./grammar/use-clause");
const identifiers = require("./grammar/identifier");
const reserved = require("./grammar/reserved");
const watch = require("./grammar/watch");
const externals = require("./grammar/externals");
const conflicts = require("./grammar/conflicts");

module.exports = grammar({
  name: "unison",
  precedences: ($) => [
    ["_expression", "identifier"],
    ["term_definition", "_expression"],
    ["keyword", "_expression"],
    ["function_application", "operator"], // `myFn a b + c` is equivalent to `((myFn a) b) + c`
    ["_infix_op_application", "_prefix_function_application"],
    ["literal_function", "function_application"],
    ["_boolean_exp", "literal_function"],
    ["constructor_or_variable_pattern", "_lhs"],
  ],
  conflicts,
  externals,
  extras: ($) => [/\\?\s/, $.comment],
  rules: {
    unison: ($) =>
      choice(
        seq(repeat($._top_item), $.namespace_pragma, repeat($._top_item)),
        repeat($._top_item),
      ),
    ...reserved,
    _top_item: ($) =>
      choice(
        $.watch_expression,
        $.test_watch_expression,
        $.type_declaration,
        alias($.documented_binding, $.term_declaration),
        alias($.binding, $.term_declaration),
        $.fold,
        $.documented_use_clause,
        $.use_clause,
        alias($.effect_declaration, $.ability_declaration),
      ),
    namespace_pragma: ($) =>
      prec.right(
        seq(
          $.kw_namespace,
          alias($._identifier, $.namespace),
        ),
      ),
    ...bindings,
    ...types,
    ...useClause,
    ...identifiers,
    ...watch,
  },
});