Default to using php-yacc to generate the parsers

composer.json

@@ -17,7 +17,8 @@
         "ext-tokenizer": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "^6.5 || ^7.0 || ^8.0"
+        "phpunit/phpunit": "^6.5 || ^7.0 || ^8.0",
+        "ircmaxell/php-yacc": "0.0.4"
     },
     "extra": {
         "branch-alias": {

grammar/README.md

@@ -21,8 +21,10 @@ applied to it:
 Building the parser
 ===================
 
-In order to rebuild the parser, you need [moriyoshi's fork of kmyacc](https://github.com/moriyoshi/kmyacc-forked).
-After you compiled/installed it, run the `rebuildParsers.php` script.
+Run `php grammar/rebuildParsers.php` to rebuild the parsers. Additional options:
 
-By default only the `Parser.php` is built. If you want to additionally emit debug symbols and create `y.output`, run the
-script with `--debug`. If you want to retain the preprocessed grammar pass `--keep-tmp-grammar`.
+ * The `KMYACC` environment variable can be used to specify an alternative `kmyacc` binary.
+   By default the `phpyacc` dev dependency will be used. To use the original `kmyacc`, you
+   need to compile [moriyoshi's fork](https://github.com/moriyoshi/kmyacc-forked).
+ * The `--debug` option enables emission of debug symbols and creates the `y.output` file.
+ * The `--keep-tmp-grammar` option preserves the preprocessed grammar file.

grammar/rebuildParsers.php

@@ -15,14 +15,8 @@
 
 $kmyacc = getenv('KMYACC');
 if (!$kmyacc) {
-    // Check for kmyacc binary in this directory, otherwise fall back to global name
-    if (file_exists(__DIR__ . '/kmyacc.exe')) {
-        $kmyacc = __DIR__ . '/kmyacc.exe';
-    } else if (file_exists(__DIR__ . '/kmyacc')) {
-        $kmyacc = __DIR__ . '/kmyacc';
-    } else {
-        $kmyacc = 'kmyacc';
-    }
+    // Use phpyacc from dev dependencies by default.
+    $kmyacc = PHP_BINARY . ' ' . __DIR__ . '/../vendor/bin/phpyacc';
 }
 
 $options = array_flip($argv);