Add Tree-sitter grammar for Decodal

2026-06-16 12:01:29 +09:00
parent f1a5836247
commit 58d2c9b423
39 changed files with 8453 additions and 1 deletions
@@ -0,0 +1,186 @@
+const PREC = {
+  DEFAULT: 1,
+  PATCH: 2,
+  AND: 3,
+  CALL: 7,
+  PATH: 8,
+};
+
+function commaSep(rule) {
+  return optional(seq(rule, repeat(seq(',', rule)), optional(',')));
+}
+
+function semiSep(rule) {
+  return optional(seq(rule, repeat(seq(';', rule)), optional(';')));
+}
+
+module.exports = grammar({
+  name: 'decodal',
+
+  extras: $ => [
+    /[\s\uFEFF\u2060\u200B]/,
+    $.comment,
+  ],
+
+  word: $ => $.identifier,
+
+  conflicts: $ => [
+    [$._expression, $.parameter],
+  ],
+
+  rules: {
+    source_file: $ => repeat($._statement),
+
+    _statement: $ => choice(
+      seq($.field_definition, optional(';')),
+      seq($._expression, optional(';')),
+    ),
+
+    comment: _ => token(seq('#', /.*/)),
+
+    _expression: $ => choice(
+      $.literal,
+      $.identifier,
+      $.regex_literal,
+      $.comparison_constraint,
+      $.object,
+      $.array,
+      $.let_expression,
+      $.function_expression,
+      $.match_expression,
+      $.import_expression,
+      $.parenthesized_expression,
+      $.call_expression,
+      $.path_expression,
+      $.binary_expression,
+      $.default_expression,
+    ),
+
+    literal: $ => choice(
+      $.string,
+      $.integer,
+      $.float,
+      $.boolean,
+    ),
+
+    boolean: _ => choice('true', 'false'),
+
+    string: _ => token(seq(
+      '"',
+      repeat(choice(/[^"\\\n]/, /\\./)),
+      '"',
+    )),
+
+    integer: _ => token(/[0-9]+/),
+    float: _ => token(/[0-9]+\.[0-9]+/),
+
+    identifier: _ => /[A-Za-z][A-Za-z0-9_]*/,
+
+    regex_literal: _ => token(seq(
+      '/',
+      repeat1(choice(/[^\/\\\n]/, /\\./)),
+      '/',
+    )),
+
+    object: $ => seq(
+      '{',
+      semiSep($.field_definition),
+      '}',
+    ),
+
+    field_definition: $ => seq(
+      field('path', $.field_path),
+      '=',
+      field('value', $._expression),
+    ),
+
+    field_path: $ => prec(10, seq(
+      $.identifier,
+      repeat(seq('.', $.identifier)),
+    )),
+
+    array: $ => seq(
+      '[',
+      commaSep($._expression),
+      ']',
+    ),
+
+    let_expression: $ => seq(
+      'let',
+      repeat(seq($.field_definition, ';')),
+      'in',
+      field('body', $._expression),
+    ),
+
+    function_expression: $ => prec.right(seq(
+      '(',
+      commaSep($.parameter),
+      ')',
+      '=>',
+      field('body', $._expression),
+    )),
+
+    parameter: $ => seq(
+      field('name', $.identifier),
+      optional(seq(':', field('constraint', $._expression))),
+    ),
+
+    match_expression: $ => seq(
+      'match',
+      field('scrutinee', $._expression),
+      '{',
+      semiSep($.match_arm),
+      '}',
+    ),
+
+    match_arm: $ => seq(
+      field('pattern', choice('_', $._expression)),
+      ':',
+      field('body', $._expression),
+    ),
+
+    import_expression: $ => seq(
+      'import',
+      field('specifier', $.string),
+    ),
+
+    parenthesized_expression: $ => seq('(', $._expression, ')'),
+
+    call_expression: $ => prec.left(PREC.CALL, seq(
+      field('function', $._expression),
+      '(',
+      commaSep($._expression),
+      ')',
+    )),
+
+    path_expression: $ => prec.left(PREC.PATH, seq(
+      field('object', $._expression),
+      '.',
+      field('field', $.identifier),
+    )),
+
+    comparison_constraint: $ => prec(6, seq(
+      field('operator', choice('>', '>=', '<', '<=')),
+      field('value', choice($.integer, $.float)),
+    )),
+
+    binary_expression: $ => choice(
+      prec.left(PREC.AND, seq(
+        field('left', $._expression),
+        field('operator', '&'),
+        field('right', $._expression),
+      )),
+      prec.left(PREC.PATCH, seq(
+        field('left', $._expression),
+        field('operator', token(prec(2, '//'))),
+        field('right', $._expression),
+      )),
+    ),
+
+    default_expression: $ => prec.right(PREC.DEFAULT, seq(
+      field('base', $._expression),
+      'default',
+      field('fallback', $._expression),
+    )),
+  },
+});