Text_Diff_Engine_string

23class Text_Diff_Engine_string {24 25    /**26     * Parses a unified or context diff.27     *28     * First param contains the whole diff and the second can be used to force29     * a specific diff type. If the second parameter is 'autodetect', the30     * diff will be examined to find out which type of diff this is.31     *32     * @param string $diff  The diff content.33     * @param string $mode  The diff mode of the content in $diff. One of34     *                      'context', 'unified', or 'autodetect'.35     *36     * @return array  List of all diff operations.37     */38    function diff($diff, $mode = 'autodetect')39    {40        // Detect line breaks.41        $lnbr = "\n";42        if (strpos($diff, "\r\n") !== false) {43            $lnbr = "\r\n";44        } elseif (strpos($diff, "\r") !== false) {45            $lnbr = "\r";46        }47 48        // Make sure we have a line break at the EOF.49        if (substr($diff, -strlen($lnbr)) != $lnbr) {50            $diff .= $lnbr;51        }52 53        if ($mode != 'autodetect' && $mode != 'context' && $mode != 'unified') {54            return PEAR::raiseError('Type of diff is unsupported');55        }56 57        if ($mode == 'autodetect') {58            $context = strpos($diff, '***');59            $unified = strpos($diff, '---');60            if ($context === $unified) {61                return PEAR::raiseError('Type of diff could not be detected');62            } elseif ($context === false || $unified === false) {63                $mode = $context !== false ? 'context' : 'unified';64            } else {65                $mode = $context < $unified ? 'context' : 'unified';66            }67        }68 69        // Split by new line and remove the diff header, if there is one.70        $diff = explode($lnbr, $diff);71        if (($mode == 'context' && strpos($diff[0], '***') === 0) ||72            ($mode == 'unified' && strpos($diff[0], '---') === 0)) {73            array_shift($diff);74            array_shift($diff);75        }76 77        if ($mode == 'context') {78            return $this->parseContextDiff($diff);79        } else {80            return $this->parseUnifiedDiff($diff);81        }82    }83 84    /**85     * Parses an array containing the unified diff.86     *87     * @param array $diff  Array of lines.88     *89     * @return array  List of all diff operations.90     */91    function parseUnifiedDiff($diff)92    {93        $edits = array();94        $end = count($diff) - 1;95        for ($i = 0; $i < $end;) {96            $diff1 = array();97            switch (substr($diff[$i], 0, 1)) {98            case ' ':99                do {100                    $diff1[] = substr($diff[$i], 1);101                } while (++$i < $end && substr($diff[$i], 0, 1) == ' ');102                $edits[] = new Text_Diff_Op_copy($diff1);