* 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.
+ *
+ * @param $startDelim
+ * @param $endDelim
+ * @param $replace
+ * @param $subject
+ *
+ * @return string
*/
static function hungryDelimiterReplace( $startDelim, $endDelim, $replace, $subject ) {
$segments = explode( $startDelim, $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/.
+ *
+ * @param $startDelim String: start delimiter
+ * @param $endDelim String: end delimiter
+ * @param $callback Callback: function to call on each match
+ * @param $subject String
+ * @param $flags String: regular expression flags
+ * @return string
*/
- # 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;
}
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
+ $inputPos = $tokenOffset + $tokenLength;
# Write out the non-matching section
$output .= substr( $subject, $outputPos, $tokenOffset - $outputPos );
$outputPos = $tokenOffset;
$contentPos = $inputPos;
$foundStart = true;
+ } else {
+ # Move the input position past the *first character* of START,
+ # to protect against missing END when it overlaps with START
+ $inputPos = $tokenOffset + 1;
}
} elseif ( $tokenType == 'end' ) {
if ( $foundStart ) {
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
+ * @param $startDelim String: start delimiter regular expression
+ * @param $endDelim String: end delimiter regular expression
+ * @param $replace String: replacement string. May contain $1, which will be
+ * replaced by the text between the delimiters
+ * @param $subject String to search
+ * @param $flags String: regular expression flags
+ * @return String: The string with the matches replaced
*/
static function delimiterReplace( $startDelim, $endDelim, $replace, $subject, $flags = '' ) {
$replacer = new RegexlikeReplacer( $replace );
/**
* More or less "markup-safe" explode()
* Ignores any instances of the separator inside <...>
- * @param string $separator
- * @param string $text
+ * @param $separator String
+ * @param $text String
* @return array
*/
static function explodeMarkup( $separator, $text ) {
* Escape a string to make it suitable for inclusion in a preg_replace()
* replacement parameter.
*
- * @param string $string
- * @return string
+ * @param $string String
+ * @return String
*/
static function escapeRegexReplacement( $string ) {
$string = str_replace( '\\', '\\\\', $string );
$string = str_replace( '$', '\\$', $string );
return $string;
}
+
+ /**
+ * Workalike for explode() with limited memory usage.
+ * Returns an Iterator
+ * @param $separator
+ * @param $subject
+ * @return \ArrayIterator|\ExplodeIterator
+ */
+ static function explode( $separator, $subject ) {
+ if ( substr_count( $subject, $separator ) > 1000 ) {
+ return new ExplodeIterator( $separator, $subject );
+ } else {
+ return new ArrayIterator( explode( $separator, $subject ) );
+ }
+ }
}
/**
return $result;
}
}
+
+/**
+ * An iterator which works exactly like:
+ *
+ * foreach ( explode( $delim, $s ) as $element ) {
+ * ...
+ * }
+ *
+ * Except it doesn't use 193 byte per element
+ */
+class ExplodeIterator implements Iterator {
+ // The subject string
+ var $subject, $subjectLength;
+
+ // The delimiter
+ var $delim, $delimLength;
+
+ // The position of the start of the line
+ var $curPos;
+
+ // The position after the end of the next delimiter
+ var $endPos;
+
+ // The current token
+ var $current;
+
+ /**
+ * Construct a DelimIterator
+ */
+ function __construct( $delim, $s ) {
+ $this->subject = $s;
+ $this->delim = $delim;
+
+ // Micro-optimisation (theoretical)
+ $this->subjectLength = strlen( $s );
+ $this->delimLength = strlen( $delim );
+
+ $this->rewind();
+ }
+
+ function rewind() {
+ $this->curPos = 0;
+ $this->endPos = strpos( $this->subject, $this->delim );
+ $this->refreshCurrent();
+ }
+
+
+ function refreshCurrent() {
+ if ( $this->curPos === false ) {
+ $this->current = false;
+ } elseif ( $this->curPos >= $this->subjectLength ) {
+ $this->current = '';
+ } elseif ( $this->endPos === false ) {
+ $this->current = substr( $this->subject, $this->curPos );
+ } else {
+ $this->current = substr( $this->subject, $this->curPos, $this->endPos - $this->curPos );
+ }
+ }
+
+ function current() {
+ return $this->current;
+ }
+
+ function key() {
+ return $this->curPos;
+ }
+
+ function next() {
+ if ( $this->endPos === false ) {
+ $this->curPos = false;
+ } else {
+ $this->curPos = $this->endPos + $this->delimLength;
+ if ( $this->curPos >= $this->subjectLength ) {
+ $this->endPos = false;
+ } else {
+ $this->endPos = strpos( $this->subject, $this->delim, $this->curPos );
+ }
+ }
+ $this->refreshCurrent();
+ return $this->current;
+ }
+
+ function valid() {
+ return $this->curPos !== false;
+ }
+}
+