<?php


abstract class flex_scanner {
	/*
	Let's face it: PHP is not up to lexical processing. GNU flex handles
	it well, so I've created a little protocol for delegating the work.
	Extend this class so that executable() gives a path to your lexical
	analyser program.
	*/
	abstract function executable();
	function __construct($path) {
		if (!is_readable($path)) throw new Exception("$path is not readable.");
		putenv("PHP_LIME_SCAN_STDIN=$path");
		$scanner = $this->executable();
		$tokens = explode("\0", `$scanner < "\$PHP_LIME_SCAN_STDIN"`);
		array_pop($tokens);
		$this->tokens = $tokens;
		$this->lineno = 1;
	}
	function next() {
		if (list($key, $token) = each($this->tokens)) {
			list($this->lineno, $type, $text) = explode("\1", $token);
			return array($type, $text);
		}
	}
	function feed($parser) {
		while (list($type, $text) = $this->next()) {
			$parser->eat($type, $text);
		}
		return $parser->eat_eof();
	}
}