init: this is the inital commit

grammar.js

@@ -0,0 +1,77 @@
+module.exports = grammar({
+  name: "ebnf",
+
+  // Extras are tokens that can appear anywhere (like whitespace and comments)
+  extras: ($) => [/\s/, $.comment],
+
+  rules: {
+    // The entry point: a file is a repeating list of syntax rules
+    source_file: ($) => repeat($.syntax_rule),
+
+    // e.g., letter = "A" | "B" | "C" ;
+    syntax_rule: ($) =>
+      seq($.meta_identifier, "=", optional($.definitions_list), ";"),
+
+    // e.g., "A" | "B" | "C"
+    definitions_list: ($) =>
+      seq($.single_definition, repeat(seq("|", $.single_definition))),
+
+    // e.g., "A" , "B"
+    single_definition: ($) =>
+      seq($.syntactic_term, repeat(seq(",", $.syntactic_term))),
+
+    // e.g., factor - exception
+    syntactic_term: ($) =>
+      seq($.syntactic_factor, optional(seq("-", $.syntactic_factor))),
+
+    // e.g., 3 * "A"
+    syntactic_factor: ($) =>
+      seq(optional(seq($.integer, "*")), $.syntactic_primary),
+
+    syntactic_primary: ($) =>
+      choice(
+        $.optional_sequence,
+        $.repeated_sequence,
+        $.grouped_sequence,
+        $.meta_identifier,
+        $.terminal_string,
+        $.special_sequence,
+        $.empty_sequence,
+      ),
+
+    // [ ... ] or (/ ... /)
+    optional_sequence: ($) =>
+      choice(
+        seq("[", $.definitions_list, "]"),
+        seq("(/", $.definitions_list, "/)"),
+      ),
+
+    // { ... } or (: ... :)
+    repeated_sequence: ($) =>
+      choice(
+        seq("{", $.definitions_list, "}"),
+        seq("(:", $.definitions_list, ":)"),
+      ),
+
+    // ( ... )
+    grouped_sequence: ($) => seq("(", $.definitions_list, ")"),
+
+    // ? ... ?
+    special_sequence: ($) => seq("?", /[^?]*/, "?"),
+
+    empty_sequence: ($) => "()",
+
+    // Identifiers (e.g., rule_name)
+    meta_identifier: ($) => /[a-zA-Z][a-zA-Z0-9_]*/,
+
+    // Strings (e.g., "hello" or 'world')
+    terminal_string: ($) =>
+      choice(seq("'", /[^']*/, "'"), seq('"', /[^"]*/, '"')),
+
+    // Numbers (used for repetition limits)
+    integer: ($) => /[0-9]+/,
+
+    // Comments (* ... *)
+    comment: ($) => seq("(*", /[^*]*\*+([^)*][^*]*\*+)*/, ")"),
+  },
+});