PhpPeg\Rule::__construct PHP Method

    function __construct($parser, $lines)
    {
        $this->parser = $parser;
        $this->lines = $lines;
        // Find the first line (if any) that's an attached function definition. Can skip first line (unless this block is malformed)
        for ($i = 1; $i < count($lines); $i++) {
            if (preg_match(self::$function_rx, $lines[$i])) {
                break;
            }
        }
        // Then split into the two parts
        $spec = array_slice($lines, 0, $i);
        $funcs = array_slice($lines, $i);
        // Parse out the spec
        $spec = implode("\n", $spec);
        if (!preg_match(self::$rule_rx, $spec, $specmatch)) {
            user_error('Malformed rule spec ' . $spec, E_USER_ERROR);
        }
        $this->name = $specmatch['name'];
        if ($specmatch['extends']) {
            $this->extends = $this->parser->rules[$specmatch['extends']];
            if (!$this->extends) {
                user_error('Extended rule ' . $specmatch['extends'] . ' is not defined before being extended', E_USER_ERROR);
            }
        }
        $this->arguments = [];
        if ($specmatch['arguments']) {
            preg_match_all(self::$argument_rx, $specmatch['arguments'], $arguments, PREG_SET_ORDER);
            foreach ($arguments as $argument) {
                $this->arguments[trim($argument[1])] = trim($argument[2]);
            }
        }
        $this->mode = $specmatch['matchmark'] ? 'rule' : 'replace';
        if ($this->mode == 'rule') {
            $this->rule = $specmatch['rule'];
            $this->parse_rule();
        } else {
            if (!$this->extends) {
                user_error('Replace matcher, but not on an extends rule', E_USER_ERROR);
            }
            $this->replacements = [];
            preg_match_all(self::$replacement_rx, $specmatch['rule'], $replacements, PREG_SET_ORDER);
            $rule = $this->extends->rule;
            foreach ($replacements as $replacement) {
                $search = trim($replacement[1]);
                $replace = trim($replacement[3]);
                if ($replace == "''" || $replace == '""') {
                    $replace = "";
                }
                $rule = str_replace($search, ' ' . $replace . ' ', $rule);
            }
            $this->rule = $rule;
            $this->parse_rule();
        }
        // Parse out the functions
        $this->functions = [];
        $active_function = NULL;
        foreach ($funcs as $line) {
            /* Handle function definitions */
            if (preg_match(self::$function_rx, $line, $func_match, 0)) {
                $active_function = $func_match[1];
                $this->functions[$active_function] = $func_match[2] . PHP_EOL;
            } else {
                $this->functions[$active_function] .= $line . PHP_EOL;
            }
        }
    }