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Diffstat (limited to 'ext/spl/internal/cachingiterator.inc')
| -rw-r--r-- | ext/spl/internal/cachingiterator.inc | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/ext/spl/internal/cachingiterator.inc b/ext/spl/internal/cachingiterator.inc new file mode 100644 index 0000000..33258ab --- /dev/null +++ b/ext/spl/internal/cachingiterator.inc @@ -0,0 +1,157 @@ +<?php + +/** @file cachingiterator.inc + * @ingroup SPL + * @brief class CachingIterator + * @author Marcus Boerger + * @date 2003 - 2009 + * + * SPL - Standard PHP Library + */ + +/** + * @brief Cached iteration over another Iterator + * @author Marcus Boerger + * @version 1.2 + * @since PHP 5.0 + * + * This iterator wrapper does a one ahead iteration. This way it knows whether + * the inner iterator has one more element. + * + * @note If you want to convert the elements into strings and the inner + * Iterator is an internal Iterator then you need to provide the + * flag CALL_TOSTRING to do the conversion when the actual element + * is being fetched. Otherwise the conversion would happen with the + * already changed iterator. If you do not need this then it you should + * omit this flag because it costs unneccessary work and time. + */ +class CachingIterator implements OuterIterator +{ + const CALL_TOSTRING = 0x00000001; + const CATCH_GET_CHILD = 0x00000002; + const TOSTRING_USE_KEY = 0x00000010; + const TOSTRING_USE_CURRENT = 0x00000020; + + private $it; + private $current; + private $key; + private $valid; + private $strValue; + + /** Construct from another iterator + * + * @param it Iterator to cache + * @param flags Bitmask: + * - CALL_TOSTRING (whether to call __toString() for every element) + */ + function __construct(Iterator $it, $flags = self::CALL_TOSTRING) + { + if ((($flags & self::CALL_TOSTRING) && ($flags & (self::TOSTRING_USE_KEY|self::TOSTRING_USE_CURRENT))) + || ((flags & (self::CIT_TOSTRING_USE_KEY|self::CIT_TOSTRING_USE_CURRENT)) == (self::CIT_TOSTRING_USE_KEY|self::CIT_TOSTRING_USE_CURRENT))) + { + throw new InvalidArgumentException('Flags must contain only one of CIT_CALL_TOSTRING, CIT_TOSTRING_USE_KEY, CIT_TOSTRING_USE_CURRENT'); + } + $this->it = $it; + $this->flags = $flags & (0x0000FFFF); + $this->next(); + } + + /** Rewind the Iterator + */ + function rewind() + { + $this->it->rewind(); + $this->next(); + } + + /** Forward to the next element + */ + function next() + { + if ($this->valid = $this->it->valid()) { + $this->current = $this->it->current(); + $this->key = $this->it->key(); + if ($this->flags & self::CALL_TOSTRING) { + if (is_object($this->current)) { + $this->strValue = $this->current->__toString(); + } else { + $this->strValue = (string)$this->current; + } + } + } else { + $this->current = NULL; + $this->key = NULL; + $this->strValue = NULL; + } + $this->it->next(); + } + + /** @return whether the iterator is valid + */ + function valid() + { + return $this->valid; + } + + /** @return whether there is one more element + */ + function hasNext() + { + return $this->it->valid(); + } + + /** @return the current element + */ + function current() + { + return $this->current; + } + + /** @return the current key + */ + function key() + { + return $this->key; + } + + /** Aggregate the inner iterator + * + * @param func Name of method to invoke + * @param params Array of parameters to pass to method + */ + function __call($func, $params) + { + return call_user_func_array(array($this->it, $func), $params); + } + + /** @return the string represenatation that was generated for the current + * element + * @throw exception when CALL_TOSTRING was not specified in constructor + */ + function __toString() + { + if ($this->flags & self::TOSTRING_USE_KEY) + { + return $this->key; + } + else if ($this->flags & self::TOSTRING_USE_CURRENT) + { + return $this->current; + } + if (!$this->flags & self::CALL_TOSTRING) + { + throw new exception('CachingIterator does not fetch string value (see CachingIterator::__construct)'); + } + return $this->strValue; + } + + /** + * @return The inner iterator + */ + function getInnerIterator() + { + return $this->it; + } +} + +?> |