feat: add base parser

Signed-off-by: kjuulh <contact@kjuulh.io> feat: with basic assignment Signed-off-by: kjuulh <contact@kjuulh.io> feat: remove target Signed-off-by: kjuulh <contact@kjuulh.io>
2023-07-03 20:16:09 +02:00
commit 67e3f73ab4
18 changed files with 4113 additions and 0 deletions
--- a/grammar.js
+++ b/grammar.js
@@ -0,0 +1,110 @@
+const PREC = {
+  range: 15,
+  call: 14,
+  field: 13,
+  unary: 12,
+  cast: 11,
+  multiplicative: 10,
+  additive: 9,
+  shift: 8,
+  bitand: 7,
+  bitxor: 6,
+  bitor: 5,
+  comparative: 4,
+  and: 3,
+  or: 2,
+  assign: 0,
+  closure: -1,
+};
+
+module.exports = grammar({
+  name: "rhai",
+
+  externals: ($) => [
+    $._string_content,
+    $.raw_string_literal,
+    $.float_literal,
+    $.block_comment,
+  ],
+
+  extras: (_) => [/\s/],
+
+  word: ($) => $.identifier,
+
+  inline: ($) => [$._declaration_statement],
+
+  supertypes: ($) => [
+    $._expression,
+    $._literal,
+    $._literal_pattern,
+    $._declaration_statement,
+    $._pattern,
+  ],
+
+  rules: {
+    source_file: ($) => repeat($._statement),
+
+    // statements
+
+    _statement: ($) => choice($.expression_statement, $._declaration_statement),
+
+    expression_statement: ($) => choice(seq($._expression, ";")),
+
+    _declaration_statement: ($) => choice($.let_declaration),
+
+    let_declaration: ($) =>
+      seq(
+        "let",
+        field("pattern", $._pattern),
+        optional(seq("=", field("value", $._expression))),
+        ";"
+      ),
+
+    // patterns
+
+    _pattern: ($) => choice($._literal_pattern, $.identifier, "_"),
+
+    // expressions
+
+    _expression: ($) =>
+      choice($.assignment_expression, $._literal, prec.left($.identifier)),
+
+    assignment_expression: ($) =>
+      prec.left(
+        PREC.assign,
+        seq(field("left", $._expression), "=", field("right", $._expression))
+      ),
+
+    // literals
+    _literal: ($) =>
+      choice($.string_literal, $.raw_string_literal, $.integer_literal),
+
+    _literal_pattern: ($) =>
+      choice($.string_literal, $.raw_string_literal, $.integer_literal),
+
+    integer_literal: (_) => token(seq(choice(/[0-9][0-9_]*/))),
+
+    string_literal: ($) => seq(
+      alias(/b?"/, '"'),
+      repeat(choice($.escape_sequence, $._string_content)),
+      token.immediate('"')
+    ),
+
+    escape_sequence: (_) =>
+      token.immediate(
+        seq(
+          "\\",
+          choice(
+            /[^xu]/,
+            /u[0-9a-fA-F]{4}/,
+            /u{[0-9a-fA-F]+}/,
+            /x[0-9a-fA-F]{2}/
+          )
+        )
+      ),
+
+    // identifiers
+
+    identifier: ($) => /(r#)?[_\p{XID_Start}][_\p{XID_Continue}]*/,
+  },
+});