training/php-2011-10: comparison Twig-1.3.0/lib/Twig/Extension/Core.php

equal deleted inserted replaced

-:6d109e3804ac
+:9a001a04b634
+<?php
+if (!defined('ENT_SUBSTITUTE')) {
+define('ENT_SUBSTITUTE', 8);
+}
+/*
+* This file is part of Twig.
+*
+* (c) 2009 Fabien Potencier
+*
+* For the full copyright and license information, please view the LICENSE
+* file that was distributed with this source code.
+*/
+class Twig_Extension_Core extends Twig_Extension
+{
+/**
+* Returns the token parser instance to add to the existing list.
+*
+* @return array An array of Twig_TokenParser instances
+*/
+public function getTokenParsers()
+{
+return array(
+new Twig_TokenParser_For(),
+new Twig_TokenParser_If(),
+new Twig_TokenParser_Extends(),
+new Twig_TokenParser_Include(),
+new Twig_TokenParser_Block(),
+new Twig_TokenParser_Use(),
+new Twig_TokenParser_Filter(),
+new Twig_TokenParser_Macro(),
+new Twig_TokenParser_Import(),
+new Twig_TokenParser_From(),
+new Twig_TokenParser_Set(),
+new Twig_TokenParser_Spaceless(),
+);
+}
+/**
+* Returns a list of filters to add to the existing list.
+*
+* @return array An array of filters
+*/
+public function getFilters()
+{
+$filters = array(
+// formatting filters
+'date'    => new Twig_Filter_Function('twig_date_format_filter'),
+'format'  => new Twig_Filter_Function('sprintf'),
+'replace' => new Twig_Filter_Function('twig_strtr'),
+// encoding
+'url_encode'  => new Twig_Filter_Function('twig_urlencode_filter'),
+'json_encode' => new Twig_Filter_Function('twig_jsonencode_filter'),
+// string filters
+'title'      => new Twig_Filter_Function('twig_title_string_filter', array('needs_environment' => true)),
+'capitalize' => new Twig_Filter_Function('twig_capitalize_string_filter', array('needs_environment' => true)),
+'upper'      => new Twig_Filter_Function('strtoupper'),
+'lower'      => new Twig_Filter_Function('strtolower'),
+'striptags'  => new Twig_Filter_Function('strip_tags'),
+// array helpers
+'join'    => new Twig_Filter_Function('twig_join_filter'),
+'reverse' => new Twig_Filter_Function('twig_reverse_filter'),
+'length'  => new Twig_Filter_Function('twig_length_filter', array('needs_environment' => true)),
+'sort'    => new Twig_Filter_Function('twig_sort_filter'),
+'merge'   => new Twig_Filter_Function('twig_array_merge'),
+// iteration and runtime
+'default' => new Twig_Filter_Function('twig_default_filter'),
+'keys'    => new Twig_Filter_Function('twig_get_array_keys_filter'),
+// escaping
+'escape' => new Twig_Filter_Function('twig_escape_filter', array('needs_environment' => true, 'is_safe_callback' => 'twig_escape_filter_is_safe')),
+'e'      => new Twig_Filter_Function('twig_escape_filter', array('needs_environment' => true, 'is_safe_callback' => 'twig_escape_filter_is_safe')),
+);
+if (function_exists('mb_get_info')) {
+$filters['upper'] = new Twig_Filter_Function('twig_upper_filter', array('needs_environment' => true));
+$filters['lower'] = new Twig_Filter_Function('twig_lower_filter', array('needs_environment' => true));
+}
+return $filters;
+}
+/**
+* Returns a list of global functions to add to the existing list.
+*
+* @return array An array of global functions
+*/
+public function getFunctions()
+{
+return array(
+'range'    => new Twig_Function_Function('range'),
+'constant' => new Twig_Function_Function('constant'),
+'cycle'    => new Twig_Function_Function('twig_cycle'),
+);
+}
+/**
+* Returns a list of filters to add to the existing list.
+*
+* @return array An array of filters
+*/
+public function getTests()
+{
+return array(
+'even'        => new Twig_Test_Function('twig_test_even'),
+'odd'         => new Twig_Test_Function('twig_test_odd'),
+'defined'     => new Twig_Test_Function('twig_test_defined'),
+'sameas'      => new Twig_Test_Function('twig_test_sameas'),
+'none'        => new Twig_Test_Function('twig_test_none'),
+'null'        => new Twig_Test_Function('twig_test_none'),
+'divisibleby' => new Twig_Test_Function('twig_test_divisibleby'),
+'constant'    => new Twig_Test_Function('twig_test_constant'),
+'empty'       => new Twig_Test_Function('twig_test_empty'),
+);
+}
+/**
+* Returns a list of operators to add to the existing list.
+*
+* @return array An array of operators
+*/
+public function getOperators()
+{
+return array(
+array(
+'not' => array('precedence' => 50, 'class' => 'Twig_Node_Expression_Unary_Not'),
+'-'   => array('precedence' => 50, 'class' => 'Twig_Node_Expression_Unary_Neg'),
+'+'   => array('precedence' => 50, 'class' => 'Twig_Node_Expression_Unary_Pos'),
+),
+array(
+'b-and'  => array('precedence' => 5, 'class' => 'Twig_Node_Expression_Binary_BitwiseAnd', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'b-xor'  => array('precedence' => 5, 'class' => 'Twig_Node_Expression_Binary_BitwiseXor', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'b-or'   => array('precedence' => 5, 'class' => 'Twig_Node_Expression_Binary_BitwiseOr', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'or'     => array('precedence' => 10, 'class' => 'Twig_Node_Expression_Binary_Or', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'and'    => array('precedence' => 15, 'class' => 'Twig_Node_Expression_Binary_And', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'=='     => array('precedence' => 20, 'class' => 'Twig_Node_Expression_Binary_Equal', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'!='     => array('precedence' => 20, 'class' => 'Twig_Node_Expression_Binary_NotEqual', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'<'      => array('precedence' => 20, 'class' => 'Twig_Node_Expression_Binary_Less', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'>'      => array('precedence' => 20, 'class' => 'Twig_Node_Expression_Binary_Greater', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'>='     => array('precedence' => 20, 'class' => 'Twig_Node_Expression_Binary_GreaterEqual', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'<='     => array('precedence' => 20, 'class' => 'Twig_Node_Expression_Binary_LessEqual', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'not in' => array('precedence' => 20, 'class' => 'Twig_Node_Expression_Binary_NotIn', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'in'     => array('precedence' => 20, 'class' => 'Twig_Node_Expression_Binary_In', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'+'      => array('precedence' => 30, 'class' => 'Twig_Node_Expression_Binary_Add', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'-'      => array('precedence' => 30, 'class' => 'Twig_Node_Expression_Binary_Sub', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'~'      => array('precedence' => 40, 'class' => 'Twig_Node_Expression_Binary_Concat', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'*'      => array('precedence' => 60, 'class' => 'Twig_Node_Expression_Binary_Mul', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'/'      => array('precedence' => 60, 'class' => 'Twig_Node_Expression_Binary_Div', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'//'     => array('precedence' => 60, 'class' => 'Twig_Node_Expression_Binary_FloorDiv', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'%'      => array('precedence' => 60, 'class' => 'Twig_Node_Expression_Binary_Mod', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'is'     => array('precedence' => 100, 'callable' => array($this, 'parseTestExpression'), 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'is not' => array('precedence' => 100, 'callable' => array($this, 'parseNotTestExpression'), 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'..'     => array('precedence' => 110, 'class' => 'Twig_Node_Expression_Binary_Range', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+'**'     => array('precedence' => 200, 'class' => 'Twig_Node_Expression_Binary_Power', 'associativity' => Twig_ExpressionParser::OPERATOR_RIGHT),
+),
+);
+}
+public function parseNotTestExpression(Twig_Parser $parser, $node)
+{
+return new Twig_Node_Expression_Unary_Not($this->parseTestExpression($parser, $node), $parser->getCurrentToken()->getLine());
+}
+public function parseTestExpression(Twig_Parser $parser, $node)
+{
+$stream = $parser->getStream();
+$name = $stream->expect(Twig_Token::NAME_TYPE);
+$arguments = null;
+if ($stream->test(Twig_Token::PUNCTUATION_TYPE, '(')) {
+$arguments = $parser->getExpressionParser()->parseArguments();
+}
+return new Twig_Node_Expression_Test($node, $name->getValue(), $arguments, $parser->getCurrentToken()->getLine());
+}
+/**
+* Returns the name of the extension.
+*
+* @return string The extension name
+*/
+public function getName()
+{
+return 'core';
+}
+}
+/**
+* Cycles over a value.
+*
+* @param ArrayAccess|array $values An array or an ArrayAccess instance
+* @param integer           $i      The cycle value
+*
+* @return string The next value in the cycle
+*/
+function twig_cycle($values, $i)
+{
+if (!is_array($values) && !$values instanceof ArrayAccess) {
+return $values;
+}
+return $values[$i % count($values)];
+}
+/**
+* Converts a date to the given format.
+*
+* <pre>
+*   {{ post.published_at|date("m/d/Y") }}
+* </pre>
+*
+* @param DateTime|string     $date     A date
+* @param string              $format   A format
+* @param DateTimeZone|string $timezone A timezone
+*
+* @return string The formatter date
+*/
+function twig_date_format_filter($date, $format = 'F j, Y H:i', $timezone = null)
+{
+if (!$date instanceof DateTime && !$date instanceof DateInterval) {
+if (ctype_digit((string) $date)) {
+$date = new DateTime('@'.$date);
+$date->setTimezone(new DateTimeZone(date_default_timezone_get()));
+} else {
+$date = new DateTime($date);
+}
+}
+if (null !== $timezone) {
+if (!$timezone instanceof DateTimeZone) {
+$timezone = new DateTimeZone($timezone);
+}
+$date->setTimezone($timezone);
+}
+return $date->format($format);
+}
+/**
+* URL encodes a string.
+*
+* @param string $url A URL
+* @param bool   $raw true to use rawurlencode() instead of urlencode
+*
+* @return string The URL encoded value
+*/
+function twig_urlencode_filter($url, $raw = false)
+{
+if ($raw) {
+return rawurlencode($url);
+}
+return urlencode($url);
+}
+if (version_compare(PHP_VERSION, '5.3.0', '<')) {
+/**
+* JSON encodes a PHP variable.
+*
+* @param mixed   $value   The value to encode.
+* @param integer $options Not used on PHP 5.2.x
+*
+* @return mixed The JSON encoded value
+*/
+function twig_jsonencode_filter($value, $options = 0)
+{
+if ($value instanceof Twig_Markup) {
+$value = (string) $value;
+} elseif (is_array($value)) {
+array_walk_recursive($value, '_twig_markup2string');
+}
+return json_encode($value);
+}
+} else {
+/**
+* JSON encodes a PHP variable.
+*
+* @param mixed   $value   The value to encode.
+* @param integer $options Bitmask consisting of JSON_HEX_QUOT, JSON_HEX_TAG, JSON_HEX_AMP, JSON_HEX_APOS, JSON_NUMERIC_CHECK, JSON_PRETTY_PRINT, JSON_UNESCAPED_SLASHES, JSON_FORCE_OBJECT
+*
+* @return mixed The JSON encoded value
+*/
+function twig_jsonencode_filter($value, $options = 0)
+{
+if ($value instanceof Twig_Markup) {
+$value = (string) $value;
+} elseif (is_array($value)) {
+array_walk_recursive($value, '_twig_markup2string');
+}
+return json_encode($value, $options);
+}
+}
+function _twig_markup2string(&$value)
+{
+if ($value instanceof Twig_Markup) {
+$value = (string) $value;
+}
+}
+/**
+* Merges an array with another one.
+*
+* <pre>
+*  {% set items = { 'apple': 'fruit', 'orange': 'fruit' } %}
+*
+*  {% set items = items|merge({ 'peugeot': 'car' }) %}
+*
+*  {# items now contains { 'apple': 'fruit', 'orange': 'fruit', 'peugeot': 'car' } #}
+* </pre>
+*
+* @param array $arr1 An array
+* @param array $arr2 An array
+*
+* @return array The merged array
+*/
+function twig_array_merge($arr1, $arr2)
+{
+if (!is_array($arr1) || !is_array($arr2)) {
+throw new Twig_Error_Runtime('The merge filter only work with arrays or hashes.');
+}
+return array_merge($arr1, $arr2);
+}
+/**
+* Joins the values to a string.
+*
+* The separator between elements is an empty string per default, you can define it with the optional parameter.
+*
+* <pre>
+*  {{ [1, 2, 3]|join('|') }}
+*  {# returns 1|2|3 #}
+*
+*  {{ [1, 2, 3]|join }}
+*  {# returns 123 #}
+* </pre>
+*
+* @param array  $value An array
+* @param string $glue  The separator
+*
+* @return string The concatenated string
+*/
+function twig_join_filter($value, $glue = '')
+{
+return implode($glue, (array) $value);
+}
+/**
+* Returns the value or the default value when it is undefined or empty.
+*
+* <pre>
+*
+*  {{ var.foo|default('foo item on var is not defined') }}
+*
+* </pre>
+*
+* @param mixed $value   A value
+* @param mixed $default The default value
+*
+* @param mixed The value or the default value;
+*/
+function twig_default_filter($value, $default = '')
+{
+if (twig_test_empty($value)) {
+return $default;
+} else {
+return $value;
+}
+}
+/**
+* Returns the keys for the given array.
+*
+* It is useful when you want to iterate over the keys of an array:
+*
+* <pre>
+*  {% for key in array|keys %}
+*      {# ... #}
+*  {% endfor %}
+* </pre>
+*
+* @param array $array An array
+*
+* @return array The keys
+*/
+function twig_get_array_keys_filter($array)
+{
+if (is_object($array) && $array instanceof Traversable) {
+return array_keys(iterator_to_array($array));
+}
+if (!is_array($array)) {
+return array();
+}
+return array_keys($array);
+}
+/**
+* Reverses an array.
+*
+* @param array|Traversable $array An array or a Traversable instance
+*
+* return array The array reversed
+*/
+function twig_reverse_filter($array)
+{
+if (is_object($array) && $array instanceof Traversable) {
+return array_reverse(iterator_to_array($array));
+}
+if (!is_array($array)) {
+return array();
+}
+return array_reverse($array);
+}
+/**
+* Sorts an array.
+*
+* @param array $array An array
+*/
+function twig_sort_filter($array)
+{
+asort($array);
+return $array;
+}
+/* used internally */
+function twig_in_filter($value, $compare)
+{
+if (is_array($compare)) {
+return in_array($value, $compare);
+} elseif (is_string($compare)) {
+return false !== strpos($compare, (string) $value);
+} elseif (is_object($compare) && $compare instanceof Traversable) {
+return in_array($value, iterator_to_array($compare, false));
+}
+return false;
+}
+/**
+* Replaces placeholders in a string.
+*
+* <pre>
+*  {{ "I like %this% and %that%."|replace({'%this%': foo, '%that%': "bar"}) }}
+* </pre>
+*
+* @param string $pattern      A string
+* @param string $replacements The values for the placeholders
+*
+* @return string The string where the placeholders have been replaced
+*/
+function twig_strtr($pattern, $replacements)
+{
+return str_replace(array_keys($replacements), array_values($replacements), $pattern);
+}
+/**
+* Escapes a string.
+*
+* @param Twig_Environment $env        A Twig_Environment instance
+* @param string           $string     The value to be escaped
+* @param string           $type       The escaping strategy
+* @param string           $charset    The charset
+* @param Boolean          $autoescape Whether the function is called by the auto-escaping feature (true) or by the developer (false)
+*/
+function twig_escape_filter(Twig_Environment $env, $string, $type = 'html', $charset = null, $autoescape = false)
+{
+if ($autoescape && is_object($string) && $string instanceof Twig_Markup) {
+return $string;
+}
+if (!is_string($string) && !(is_object($string) && method_exists($string, '__toString'))) {
+return $string;
+}
+if (null === $charset) {
+$charset = $env->getCharset();
+}
+switch ($type) {
+case 'js':
+// escape all non-alphanumeric characters
+// into their \xHH or \uHHHH representations
+if ('UTF-8' != $charset) {
+$string = _twig_convert_encoding($string, 'UTF-8', $charset);
+}
+if (null === $string = preg_replace_callback('#[^\p{L}\p{N} ]#u', '_twig_escape_js_callback', $string)) {
+throw new Twig_Error_Runtime('The string to escape is not a valid UTF-8 string.');
+}
+if ('UTF-8' != $charset) {
+$string = _twig_convert_encoding($string, $charset, 'UTF-8');
+}
+return $string;
+case 'html':
+return htmlspecialchars($string, ENT_QUOTES | ENT_SUBSTITUTE, $charset);
+default:
+throw new Twig_Error_Runtime(sprintf('Invalid escape type "%s".', $type));
+}
+}
+/* used internally */
+function twig_escape_filter_is_safe(Twig_Node $filterArgs)
+{
+foreach ($filterArgs as $arg) {
+if ($arg instanceof Twig_Node_Expression_Constant) {
+return array($arg->getAttribute('value'));
+} else {
+return array();
+}
+break;
+}
+return array('html');
+}
+if (function_exists('iconv')) {
+function _twig_convert_encoding($string, $to, $from)
+{
+return iconv($from, $to, $string);
+}
+} elseif (function_exists('mb_convert_encoding')) {
+function _twig_convert_encoding($string, $to, $from)
+{
+return mb_convert_encoding($string, $to, $from);
+}
+} else {
+function _twig_convert_encoding($string, $to, $from)
+{
+throw new Twig_Error_Runtime('No suitable convert encoding function (use UTF-8 as your encoding or install the iconv or mbstring extension).');
+}
+}
+function _twig_escape_js_callback($matches)
+{
+$char = $matches[0];
+// \xHH
+if (!isset($char[1])) {
+return '\\x'.substr('00'.bin2hex($char), -2);
+}
+// \uHHHH
+$char = _twig_convert_encoding($char, 'UTF-16BE', 'UTF-8');
+return '\\u'.substr('0000'.bin2hex($char), -4);
+}
+// add multibyte extensions if possible
+if (function_exists('mb_get_info')) {
+/**
+* Returns the length of a PHP variable.
+*
+* @param Twig_Environment $env   A Twig_Environment instance
+* @param mixed            $thing A PHP variable
+*
+* @return integer The length of the value
+*/
+function twig_length_filter(Twig_Environment $env, $thing)
+{
+return is_scalar($thing) ? mb_strlen($thing, $env->getCharset()) : count($thing);
+}
+/**
+* Converts a string to uppercase.
+*
+* @param Twig_Environment $env    A Twig_Environment instance
+* @param string           $string A string
+*
+* @return string The uppercased string
+*/
+function twig_upper_filter(Twig_Environment $env, $string)
+{
+if (null !== ($charset = $env->getCharset())) {
+return mb_strtoupper($string, $charset);
+}
+return strtoupper($string);
+}
+/**
+* Converts a string to lowercase.
+*
+* @param Twig_Environment $env    A Twig_Environment instance
+* @param string           $string A string
+*
+* @return string The lowercased string
+*/
+function twig_lower_filter(Twig_Environment $env, $string)
+{
+if (null !== ($charset = $env->getCharset())) {
+return mb_strtolower($string, $charset);
+}
+return strtolower($string);
+}
+/**
+* Returns a titlecased string.
+*
+* @param Twig_Environment $env    A Twig_Environment instance
+* @param string           $string A string
+*
+* @return string The titlecased string
+*/
+function twig_title_string_filter(Twig_Environment $env, $string)
+{
+if (null !== ($charset = $env->getCharset())) {
+return mb_convert_case($string, MB_CASE_TITLE, $charset);
+}
+return ucwords(strtolower($string));
+}
+/**
+* Returns a capitalized string.
+*
+* @param Twig_Environment $env    A Twig_Environment instance
+* @param string           $string A string
+*
+* @return string The capitalized string
+*/
+function twig_capitalize_string_filter(Twig_Environment $env, $string)
+{
+if (null !== ($charset = $env->getCharset())) {
+return mb_strtoupper(mb_substr($string, 0, 1, $charset), $charset).
+mb_strtolower(mb_substr($string, 1, mb_strlen($string, $charset), $charset), $charset);
+}
+return ucfirst(strtolower($string));
+}
+}
+// and byte fallback
+else
+{
+/**
+* Returns the length of a PHP variable.
+*
+* @param Twig_Environment $env   A Twig_Environment instance
+* @param mixed            $thing A PHP variable
+*
+* @return integer The length of the value
+*/
+function twig_length_filter(Twig_Environment $env, $thing)
+{
+return is_scalar($thing) ? strlen($thing) : count($thing);
+}
+/**
+* Returns a titlecased string.
+*
+* @param Twig_Environment $env    A Twig_Environment instance
+* @param string           $string A string
+*
+* @return string The titlecased string
+*/
+function twig_title_string_filter(Twig_Environment $env, $string)
+{
+return ucwords(strtolower($string));
+}
+/**
+* Returns a capitalized string.
+*
+* @param Twig_Environment $env    A Twig_Environment instance
+* @param string           $string A string
+*
+* @return string The capitalized string
+*/
+function twig_capitalize_string_filter(Twig_Environment $env, $string)
+{
+return ucfirst(strtolower($string));
+}
+}
+/* used internally */
+function twig_ensure_traversable($seq)
+{
+if (is_array($seq) || (is_object($seq) && $seq instanceof Traversable)) {
+return $seq;
+} else {
+return array();
+}
+}
+/**
+* Checks that a variable points to the same memory address than another one.
+*
+* <pre>
+* {% if foo.attribute is sameas(false) %}
+*    the foo attribute really is the ``false`` PHP value
+* {% endif %}
+* </pre>
+*
+* @param mixed $value A PHP variable
+* @param mixed $test  The PHP variable to test against
+*
+* @return Boolean true if the values are the same, false otherwise
+*/
+function twig_test_sameas($value, $test)
+{
+return $value === $test;
+}
+/**
+* Checks that a variable is null.
+*
+* <pre>
+*  {{ var is none }}
+* </pre>
+*
+* @param mixed $value a PHP variable.
+*
+* @return Boolean true if the value is null, false otherwise
+*/
+function twig_test_none($value)
+{
+return null === $value;
+}
+/**
+* Checks if a variable is divisible by a number.
+*
+* <pre>
+*  {% if loop.index is divisibleby(3) %}
+* </pre>
+*
+* @param integer $value A PHP value
+* @param integer $num   A number
+*
+* @return Boolean true if the value is divisible by the number, false otherwise
+*/
+function twig_test_divisibleby($value, $num)
+{
+return 0 == $value % $num;
+}
+/**
+* Checks if a number is even.
+*
+* <pre>
+*  {{ var is even }}
+* </pre>
+*
+* @param integer $value An integer
+*
+* @return Boolean true if the value is even, false otherwise
+*/
+function twig_test_even($value)
+{
+return $value % 2 == 0;
+}
+/**
+* Checks if a number is odd.
+*
+* <pre>
+*  {{ var is odd }}
+* </pre>
+*
+* @param integer $value An integer
+*
+* @return Boolean true if the value is odd, false otherwise
+*/
+function twig_test_odd($value)
+{
+return $value % 2 == 1;
+}
+/**
+* Checks if a variable is the exact same value as a constant.
+*
+* <pre>
+*  {% if post.status is constant('Post::PUBLISHED') %}
+*    the status attribute is exactly the same as Post::PUBLISHED
+*  {% endif %}
+* </pre>
+*
+* @param mixed $value    A PHP value
+* @param mixed $constant The constant to test against
+*
+* @return Boolean true if the value is the same as the constant, false otherwise
+*/
+function twig_test_constant($value, $constant)
+{
+return constant($constant) === $value;
+}
+/**
+* Checks if a variable is defined in the current context.
+*
+* <pre>
+* {# defined works with variable names #}
+* {% if foo is defined %}
+*     {# ... #}
+* {% endif %}
+* </pre>
+*
+* @param mixed $name    A PHP variable
+* @param array $context The current context
+*
+* @return Boolean true if the value is defined, false otherwise
+*/
+function twig_test_defined($name, $context)
+{
+return array_key_exists($name, $context);
+}
+/**
+* Checks if a variable is empty.
+*
+* <pre>
+* {# evaluates to true if the foo variable is null, false, or the empty string #}
+* {% if foo is empty %}
+*     {# ... #}
+* {% endif %}
+* </pre>
+*
+* @param mixed $value A PHP variable
+*
+* @return Boolean true if the value is empty, false otherwise
+*/
+function twig_test_empty($value)
+{
+if ($value instanceof Countable) {
+return 0 == count($value);
+}
+return false === $value || (empty($value) && '0' != $value);
+}