diff options
author | Pierre Schmitz <pierre@archlinux.de> | 2007-01-11 19:06:07 +0000 |
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committer | Pierre Schmitz <pierre@archlinux.de> | 2007-01-11 19:06:07 +0000 |
commit | a58285fd06c8113c45377c655dd43cef6337e815 (patch) | |
tree | dfe31d3d12652352fe44890b4811eda0728faefb /includes/StringUtils.php | |
parent | 20194986f6638233732ba1fc3e838f117d3cc9ea (diff) |
Aktualisierung auf MediaWiki 1.9.0
Diffstat (limited to 'includes/StringUtils.php')
-rw-r--r-- | includes/StringUtils.php | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/includes/StringUtils.php b/includes/StringUtils.php new file mode 100644 index 00000000..0090604d --- /dev/null +++ b/includes/StringUtils.php @@ -0,0 +1,301 @@ +<?php + +class StringUtils { + /** + * Perform an operation equivalent to + * + * preg_replace( "!$startDelim(.*?)$endDelim!", $replace, $subject ); + * + * except that it's worst-case O(N) instead of O(N^2) + * + * Compared to delimiterReplace(), this implementation is fast but memory- + * hungry and inflexible. The memory requirements are such that I don't + * recommend using it on anything but guaranteed small chunks of text. + */ + static function hungryDelimiterReplace( $startDelim, $endDelim, $replace, $subject ) { + $segments = explode( $startDelim, $subject ); + $output = array_shift( $segments ); + foreach ( $segments as $s ) { + $endDelimPos = strpos( $s, $endDelim ); + if ( $endDelimPos === false ) { + $output .= $startDelim . $s; + } else { + $output .= $replace . substr( $s, $endDelimPos + strlen( $endDelim ) ); + } + } + return $output; + } + + /** + * Perform an operation equivalent to + * + * preg_replace_callback( "!$startDelim(.*)$endDelim!s$flags", $callback, $subject ) + * + * This implementation is slower than hungryDelimiterReplace but uses far less + * memory. The delimiters are literal strings, not regular expressions. + * + * @param string $flags Regular expression flags + */ + # If the start delimiter ends with an initial substring of the end delimiter, + # e.g. in the case of C-style comments, the behaviour differs from the model + # regex. In this implementation, the end must share no characters with the + # start, so e.g. /*/ is not considered to be both the start and end of a + # comment. /*/xy/*/ is considered to be a single comment with contents /xy/. + static function delimiterReplaceCallback( $startDelim, $endDelim, $callback, $subject, $flags = '' ) { + $inputPos = 0; + $outputPos = 0; + $output = ''; + $foundStart = false; + $encStart = preg_quote( $startDelim, '!' ); + $encEnd = preg_quote( $endDelim, '!' ); + $strcmp = strpos( $flags, 'i' ) === false ? 'strcmp' : 'strcasecmp'; + $endLength = strlen( $endDelim ); + $m = array(); + + while ( $inputPos < strlen( $subject ) && + preg_match( "!($encStart)|($encEnd)!S$flags", $subject, $m, PREG_OFFSET_CAPTURE, $inputPos ) ) + { + $tokenOffset = $m[0][1]; + if ( $m[1][0] != '' ) { + if ( $foundStart && + $strcmp( $endDelim, substr( $subject, $tokenOffset, $endLength ) ) == 0 ) + { + # An end match is present at the same location + $tokenType = 'end'; + $tokenLength = $endLength; + } else { + $tokenType = 'start'; + $tokenLength = strlen( $m[0][0] ); + } + } elseif ( $m[2][0] != '' ) { + $tokenType = 'end'; + $tokenLength = strlen( $m[0][0] ); + } else { + throw new MWException( 'Invalid delimiter given to ' . __METHOD__ ); + } + + if ( $tokenType == 'start' ) { + $inputPos = $tokenOffset + $tokenLength; + # Only move the start position if we haven't already found a start + # This means that START START END matches outer pair + if ( !$foundStart ) { + # Found start + # Write out the non-matching section + $output .= substr( $subject, $outputPos, $tokenOffset - $outputPos ); + $outputPos = $tokenOffset; + $contentPos = $inputPos; + $foundStart = true; + } + } elseif ( $tokenType == 'end' ) { + if ( $foundStart ) { + # Found match + $output .= call_user_func( $callback, array( + substr( $subject, $outputPos, $tokenOffset + $tokenLength - $outputPos ), + substr( $subject, $contentPos, $tokenOffset - $contentPos ) + )); + $foundStart = false; + } else { + # Non-matching end, write it out + $output .= substr( $subject, $inputPos, $tokenOffset + $tokenLength - $outputPos ); + } + $inputPos = $outputPos = $tokenOffset + $tokenLength; + } else { + throw new MWException( 'Invalid delimiter given to ' . __METHOD__ ); + } + } + if ( $outputPos < strlen( $subject ) ) { + $output .= substr( $subject, $outputPos ); + } + return $output; + } + + /* + * Perform an operation equivalent to + * + * preg_replace( "!$startDelim(.*)$endDelim!$flags", $replace, $subject ) + * + * @param string $startDelim Start delimiter regular expression + * @param string $endDelim End delimiter regular expression + * @param string $replace Replacement string. May contain $1, which will be + * replaced by the text between the delimiters + * @param string $subject String to search + * @return string The string with the matches replaced + */ + static function delimiterReplace( $startDelim, $endDelim, $replace, $subject, $flags = '' ) { + $replacer = new RegexlikeReplacer( $replace ); + return self::delimiterReplaceCallback( $startDelim, $endDelim, + $replacer->cb(), $subject, $flags ); + } + + /** + * More or less "markup-safe" explode() + * Ignores any instances of the separator inside <...> + * @param string $separator + * @param string $text + * @return array + */ + static function explodeMarkup( $separator, $text ) { + $placeholder = "\x00"; + + // Remove placeholder instances + $text = str_replace( $placeholder, '', $text ); + + // Replace instances of the separator inside HTML-like tags with the placeholder + $replacer = new DoubleReplacer( $separator, $placeholder ); + $cleaned = StringUtils::delimiterReplaceCallback( '<', '>', $replacer->cb(), $text ); + + // Explode, then put the replaced separators back in + $items = explode( $separator, $cleaned ); + foreach( $items as $i => $str ) { + $items[$i] = str_replace( $placeholder, $separator, $str ); + } + + return $items; + } + + /** + * Escape a string to make it suitable for inclusion in a preg_replace() + * replacement parameter. + * + * @param string $string + * @return string + */ + static function escapeRegexReplacement( $string ) { + $string = str_replace( '\\', '\\\\', $string ); + $string = str_replace( '$', '\\$', $string ); + return $string; + } +} + +/** + * Base class for "replacers", objects used in preg_replace_callback() and + * StringUtils::delimiterReplaceCallback() + */ +class Replacer { + function cb() { + return array( &$this, 'replace' ); + } +} + +/** + * Class to replace regex matches with a string similar to that used in preg_replace() + */ +class RegexlikeReplacer extends Replacer { + var $r; + function __construct( $r ) { + $this->r = $r; + } + + function replace( $matches ) { + $pairs = array(); + foreach ( $matches as $i => $match ) { + $pairs["\$$i"] = $match; + } + return strtr( $this->r, $pairs ); + } + +} + +/** + * Class to perform secondary replacement within each replacement string + */ +class DoubleReplacer extends Replacer { + function __construct( $from, $to, $index = 0 ) { + $this->from = $from; + $this->to = $to; + $this->index = $index; + } + + function replace( $matches ) { + return str_replace( $this->from, $this->to, $matches[$this->index] ); + } +} + +/** + * Class to perform replacement based on a simple hashtable lookup + */ +class HashtableReplacer extends Replacer { + var $table, $index; + + function __construct( $table, $index = 0 ) { + $this->table = $table; + $this->index = $index; + } + + function replace( $matches ) { + return $this->table[$matches[$this->index]]; + } +} + +/** + * Replacement array for FSS with fallback to strtr() + * Supports lazy initialisation of FSS resource + */ +class ReplacementArray { + /*mostly private*/ var $data = false; + /*mostly private*/ var $fss = false; + + /** + * Create an object with the specified replacement array + * The array should have the same form as the replacement array for strtr() + */ + function __construct( $data = array() ) { + $this->data = $data; + } + + function __sleep() { + return array( 'data' ); + } + + function __wakeup() { + $this->fss = false; + } + + /** + * Set the whole replacement array at once + */ + function setArray( $data ) { + $this->data = $data; + $this->fss = false; + } + + function getArray() { + return $this->data; + } + + /** + * Set an element of the replacement array + */ + function setPair( $from, $to ) { + $this->data[$from] = $to; + $this->fss = false; + } + + function mergeArray( $data ) { + $this->data = array_merge( $this->data, $data ); + $this->fss = false; + } + + function merge( $other ) { + $this->data = array_merge( $this->data, $other->data ); + $this->fss = false; + } + + function replace( $subject ) { + if ( function_exists( 'fss_prep_replace' ) ) { + wfProfileIn( __METHOD__.'-fss' ); + if ( $this->fss === false ) { + $this->fss = fss_prep_replace( $this->data ); + } + $result = fss_exec_replace( $this->fss, $subject ); + wfProfileOut( __METHOD__.'-fss' ); + } else { + wfProfileIn( __METHOD__.'-strtr' ); + $result = strtr( $subject, $this->data ); + wfProfileOut( __METHOD__.'-strtr' ); + } + return $result; + } +} + +?> |