<?php /** * The string tokenizer class allows an application to break a string into tokens. * * @author Azeem Michael * @example The following is one example of the use of the tokenizer. The code: * <code> * <?php * $str = "this is:@\t\n a test!"; * $delim = " !@:'\t\n\0"; // remove these chars * $st = new StringTokenizer($str, $delim); * echo 'Total tokens: '.$st->countTokens().'<br/>'; * while ($st->hasMoreTokens()) { * echo $st->nextToken() . '<br/>'; * } * prints the following output: * Total tokens: 4 * this * is * a * test * ?> * </code> */ class StringTokenizer { /** @var string */ private $string; /** @var string */ private $token; /** @var string */ private $delim; /** * Constructs a string tokenizer for the specified string. * @param string $str String to tokenize * @param string $delim The set of delimiters (the characters that separate tokens) * specified at creation time, default to " \n\r\t\0" */ public function __construct($str, $delim=" \n\r\t\0") { $this->string = $str; $this->delim = $delim; $this->token = strtok($str, $delim); } /** * Destructor to prevent memory leaks */ public function __destruct() { unset($this); } /** * Calculates the number of times that this tokenizer's nextToken method can * be called before it generates an exception * @return int - number of tokens */ public function countTokens() { $counter = 0; while($this->hasMoreTokens()) { $counter++; $this->nextToken(); } $this->token = strtok($this->string, $this->delim); return $counter; } /** * Tests if there are more tokens available from this tokenizer's string. It * does not move the internal pointer in any way. To move the internal pointer * to the next element call nextToken() * @return boolean - true if has more tokens, false otherwise */ public function hasMoreTokens() { return ($this->token !== false); } /** * Returns the next token from this string tokenizer and advances the internal * pointer by one. * @return string - next element in the tokenized string */ public function nextToken() { $hold = $this->token; //hold current pointer value $this->token = strtok($this->delim); //increment pointer return $hold; //return current pointer value } } ?>