Collection of generic string functions and classes
This commit is contained in:
Tim Starling
parent
2f12a58d93
commit
1d2dc36ac1
1 changed files with 263 additions and 0 deletions
263
includes/StringUtils.php
Normal file
263
includes/StringUtils.php
Normal file
|
|
@ -0,0 +1,263 @@
|
|||
<?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 staticDelimiterReplace but uses far less
|
||||
* memory and allows regular expression delimiters.
|
||||
*
|
||||
* @param string $flags Regular expression flags
|
||||
*/
|
||||
static function delimiterReplaceCallback( $startDelim, $endDelim, $callback, $subject, $flags = '' ) {
|
||||
$inputPos = 0;
|
||||
$outputPos = 0;
|
||||
$output = '';
|
||||
$foundStart = false;
|
||||
|
||||
while ( $inputPos < strlen( $subject ) &&
|
||||
preg_match( "!($startDelim)|($endDelim)!$flags", $subject, $m, PREG_OFFSET_CAPTURE, $inputPos ) )
|
||||
{
|
||||
if ( $m[1][0] != '' ) {
|
||||
# Found start
|
||||
# Write out the non-matching section
|
||||
$output .= substr( $subject, $outputPos, $m[1][1] - $outputPos );
|
||||
$foundStart = true;
|
||||
$inputPos = $contentPos = $m[1][1] + strlen( $m[1][0] );
|
||||
$outputPos = $m[1][1];
|
||||
} elseif ( $m[2][0] != '' ) {
|
||||
# Found end
|
||||
if ( $foundStart ) {
|
||||
# Found match
|
||||
$output .= call_user_func( $callback, array(
|
||||
substr( $subject, $outputPos, $m[2][1] + strlen( $m[2][0] ) - $outputPos ),
|
||||
substr( $subject, $contentPos, $m[2][1] - $contentPos )
|
||||
));
|
||||
$foundStart = false;
|
||||
} else {
|
||||
# Non-matching end, write it out
|
||||
$output .= substr( $subject, $inputPos, $m[2][1] + strlen( $m[2][0] ) - $outputPos );
|
||||
}
|
||||
$inputPos = $outputPos = $m[2][1] + strlen( $m[2][0] );
|
||||
} 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' ) ) {
|
||||
if ( $this->fss === false ) {
|
||||
$this->fss = fss_prep_replace( $this->data );
|
||||
}
|
||||
return fss_exec_replace( $this->fss, $subject );
|
||||
} else {
|
||||
return strtr( $subject, $this->data );
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
?>
|
||||
Loading…
Reference in a new issue