<?php
/**
* @package DATA
*/
/**
* SQL type representation.
*
* Right now there will be no support for arbitrary size math
* operations, but these will be supported by the member
* functions in the corresponding classes. Outboxing into native
* php types and doing the math operations outside is discouraged.
*
* All classes will provide __toString() functionality for automatic
* outboxing into string representation. This will allow character
* types to be used in the usual string context without having to
* explicitly outbox the value.
*
*/
abstract class DATA_SQLType {
/**
* Flags the type to nullable or not nullable.
* @var boolean
*/
private $nullable;
/**
* Flags the value as null.
* @var boolean
*/
private $isnull;
/**
* Internal constructor. Sets the type to nullable or not nullable.
*
* @param boolean $nullable True if the type is nullable.
* @param boolean $isnull True if the initial value is null.
*/
protected function __construct($nullable, $isnull) {
$this->nullable = $nullable;
$this->isnull = false;
if ($isnull) $this->setNull();
}
/**
* Automatically outboxes the value into a native php string.
*
* @return string String representation of the value.
*/
abstract public function __toString();
/**
* Indicates if this type is nullable.
*
* @return boolean True if the type is nullable.
*/
public function isNullable() {
return $this->nullable;
}
/**
* Indicates if this value is null.
*
* Optionally, can be used statically passing the value by parameter.
*
* @return boolean True if the value is null.
*/
public function isNull() {
if (isset($this)) {
return $this->isnull;
}
$value = func_get_arg(0);
if ($value instanceof DATA_SQLType) {
return $value->isNull();
} else {
return is_null($value);
}
}
/**
* Nulls this value.
*
* Throws {@link DATA_NotNullable}.
*/
public function setNull() {
if (!$this->nullable) {
throw new DATA_NotNullable();
}
$this->isnull = true;
}
/**
* Internally flag the value as not null.
*/
protected function setNotNull() {
$this->isnull = false;
}
/**
* Outboxes the value into a php native value.
*
* @return mixed Php native value.
*/
public function outbox() {
if ($this->isnull) return null;
else return $this->__toString();
}
}
?>
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