class Twig_ExpressionParser in Zircon Profile 8
Same name and namespace in other branches
- 8.0 vendor/twig/twig/lib/Twig/ExpressionParser.php \Twig_ExpressionParser
Parses expressions.
This parser implements a "Precedence climbing" algorithm.
@author Fabien Potencier <fabien@symfony.com>
Hierarchy
- class \Twig_ExpressionParser
Expanded class hierarchy of Twig_ExpressionParser
See also
http://www.engr.mun.ca/~theo/Misc/exp_parsing.htm
http://en.wikipedia.org/wiki/Operator-precedence_parser
File
- vendor/
twig/ twig/ lib/ Twig/ ExpressionParser.php, line 23
View source
class Twig_ExpressionParser {
const OPERATOR_LEFT = 1;
const OPERATOR_RIGHT = 2;
protected $parser;
protected $unaryOperators;
protected $binaryOperators;
public function __construct(Twig_Parser $parser, array $unaryOperators, array $binaryOperators) {
$this->parser = $parser;
$this->unaryOperators = $unaryOperators;
$this->binaryOperators = $binaryOperators;
}
public function parseExpression($precedence = 0) {
$expr = $this
->getPrimary();
$token = $this->parser
->getCurrentToken();
while ($this
->isBinary($token) && $this->binaryOperators[$token
->getValue()]['precedence'] >= $precedence) {
$op = $this->binaryOperators[$token
->getValue()];
$this->parser
->getStream()
->next();
if (isset($op['callable'])) {
$expr = call_user_func($op['callable'], $this->parser, $expr);
}
else {
$expr1 = $this
->parseExpression(self::OPERATOR_LEFT === $op['associativity'] ? $op['precedence'] + 1 : $op['precedence']);
$class = $op['class'];
$expr = new $class($expr, $expr1, $token
->getLine());
}
$token = $this->parser
->getCurrentToken();
}
if (0 === $precedence) {
return $this
->parseConditionalExpression($expr);
}
return $expr;
}
protected function getPrimary() {
$token = $this->parser
->getCurrentToken();
if ($this
->isUnary($token)) {
$operator = $this->unaryOperators[$token
->getValue()];
$this->parser
->getStream()
->next();
$expr = $this
->parseExpression($operator['precedence']);
$class = $operator['class'];
return $this
->parsePostfixExpression(new $class($expr, $token
->getLine()));
}
elseif ($token
->test(Twig_Token::PUNCTUATION_TYPE, '(')) {
$this->parser
->getStream()
->next();
$expr = $this
->parseExpression();
$this->parser
->getStream()
->expect(Twig_Token::PUNCTUATION_TYPE, ')', 'An opened parenthesis is not properly closed');
return $this
->parsePostfixExpression($expr);
}
return $this
->parsePrimaryExpression();
}
protected function parseConditionalExpression($expr) {
while ($this->parser
->getStream()
->nextIf(Twig_Token::PUNCTUATION_TYPE, '?')) {
if (!$this->parser
->getStream()
->nextIf(Twig_Token::PUNCTUATION_TYPE, ':')) {
$expr2 = $this
->parseExpression();
if ($this->parser
->getStream()
->nextIf(Twig_Token::PUNCTUATION_TYPE, ':')) {
$expr3 = $this
->parseExpression();
}
else {
$expr3 = new Twig_Node_Expression_Constant('', $this->parser
->getCurrentToken()
->getLine());
}
}
else {
$expr2 = $expr;
$expr3 = $this
->parseExpression();
}
$expr = new Twig_Node_Expression_Conditional($expr, $expr2, $expr3, $this->parser
->getCurrentToken()
->getLine());
}
return $expr;
}
protected function isUnary(Twig_Token $token) {
return $token
->test(Twig_Token::OPERATOR_TYPE) && isset($this->unaryOperators[$token
->getValue()]);
}
protected function isBinary(Twig_Token $token) {
return $token
->test(Twig_Token::OPERATOR_TYPE) && isset($this->binaryOperators[$token
->getValue()]);
}
public function parsePrimaryExpression() {
$token = $this->parser
->getCurrentToken();
switch ($token
->getType()) {
case Twig_Token::NAME_TYPE:
$this->parser
->getStream()
->next();
switch ($token
->getValue()) {
case 'true':
case 'TRUE':
$node = new Twig_Node_Expression_Constant(true, $token
->getLine());
break;
case 'false':
case 'FALSE':
$node = new Twig_Node_Expression_Constant(false, $token
->getLine());
break;
case 'none':
case 'NONE':
case 'null':
case 'NULL':
$node = new Twig_Node_Expression_Constant(null, $token
->getLine());
break;
default:
if ('(' === $this->parser
->getCurrentToken()
->getValue()) {
$node = $this
->getFunctionNode($token
->getValue(), $token
->getLine());
}
else {
$node = new Twig_Node_Expression_Name($token
->getValue(), $token
->getLine());
}
}
break;
case Twig_Token::NUMBER_TYPE:
$this->parser
->getStream()
->next();
$node = new Twig_Node_Expression_Constant($token
->getValue(), $token
->getLine());
break;
case Twig_Token::STRING_TYPE:
case Twig_Token::INTERPOLATION_START_TYPE:
$node = $this
->parseStringExpression();
break;
case Twig_Token::OPERATOR_TYPE:
if (preg_match(Twig_Lexer::REGEX_NAME, $token
->getValue(), $matches) && $matches[0] == $token
->getValue()) {
// in this context, string operators are variable names
$this->parser
->getStream()
->next();
$node = new Twig_Node_Expression_Name($token
->getValue(), $token
->getLine());
break;
}
elseif (isset($this->unaryOperators[$token
->getValue()])) {
$class = $this->unaryOperators[$token
->getValue()]['class'];
$ref = new ReflectionClass($class);
$negClass = 'Twig_Node_Expression_Unary_Neg';
$posClass = 'Twig_Node_Expression_Unary_Pos';
if (!(in_array($ref
->getName(), array(
$negClass,
$posClass,
)) || $ref
->isSubclassOf($negClass) || $ref
->isSubclassOf($posClass))) {
throw new Twig_Error_Syntax(sprintf('Unexpected unary operator "%s".', $token
->getValue()), $token
->getLine(), $this->parser
->getFilename());
}
$this->parser
->getStream()
->next();
$expr = $this
->parsePrimaryExpression();
$node = new $class($expr, $token
->getLine());
break;
}
default:
if ($token
->test(Twig_Token::PUNCTUATION_TYPE, '[')) {
$node = $this
->parseArrayExpression();
}
elseif ($token
->test(Twig_Token::PUNCTUATION_TYPE, '{')) {
$node = $this
->parseHashExpression();
}
else {
throw new Twig_Error_Syntax(sprintf('Unexpected token "%s" of value "%s".', Twig_Token::typeToEnglish($token
->getType()), $token
->getValue()), $token
->getLine(), $this->parser
->getFilename());
}
}
return $this
->parsePostfixExpression($node);
}
public function parseStringExpression() {
$stream = $this->parser
->getStream();
$nodes = array();
// a string cannot be followed by another string in a single expression
$nextCanBeString = true;
while (true) {
if ($nextCanBeString && ($token = $stream
->nextIf(Twig_Token::STRING_TYPE))) {
$nodes[] = new Twig_Node_Expression_Constant($token
->getValue(), $token
->getLine());
$nextCanBeString = false;
}
elseif ($stream
->nextIf(Twig_Token::INTERPOLATION_START_TYPE)) {
$nodes[] = $this
->parseExpression();
$stream
->expect(Twig_Token::INTERPOLATION_END_TYPE);
$nextCanBeString = true;
}
else {
break;
}
}
$expr = array_shift($nodes);
foreach ($nodes as $node) {
$expr = new Twig_Node_Expression_Binary_Concat($expr, $node, $node
->getLine());
}
return $expr;
}
public function parseArrayExpression() {
$stream = $this->parser
->getStream();
$stream
->expect(Twig_Token::PUNCTUATION_TYPE, '[', 'An array element was expected');
$node = new Twig_Node_Expression_Array(array(), $stream
->getCurrent()
->getLine());
$first = true;
while (!$stream
->test(Twig_Token::PUNCTUATION_TYPE, ']')) {
if (!$first) {
$stream
->expect(Twig_Token::PUNCTUATION_TYPE, ',', 'An array element must be followed by a comma');
// trailing ,?
if ($stream
->test(Twig_Token::PUNCTUATION_TYPE, ']')) {
break;
}
}
$first = false;
$node
->addElement($this
->parseExpression());
}
$stream
->expect(Twig_Token::PUNCTUATION_TYPE, ']', 'An opened array is not properly closed');
return $node;
}
public function parseHashExpression() {
$stream = $this->parser
->getStream();
$stream
->expect(Twig_Token::PUNCTUATION_TYPE, '{', 'A hash element was expected');
$node = new Twig_Node_Expression_Array(array(), $stream
->getCurrent()
->getLine());
$first = true;
while (!$stream
->test(Twig_Token::PUNCTUATION_TYPE, '}')) {
if (!$first) {
$stream
->expect(Twig_Token::PUNCTUATION_TYPE, ',', 'A hash value must be followed by a comma');
// trailing ,?
if ($stream
->test(Twig_Token::PUNCTUATION_TYPE, '}')) {
break;
}
}
$first = false;
// a hash key can be:
//
// * a number -- 12
// * a string -- 'a'
// * a name, which is equivalent to a string -- a
// * an expression, which must be enclosed in parentheses -- (1 + 2)
if (($token = $stream
->nextIf(Twig_Token::STRING_TYPE)) || ($token = $stream
->nextIf(Twig_Token::NAME_TYPE)) || ($token = $stream
->nextIf(Twig_Token::NUMBER_TYPE))) {
$key = new Twig_Node_Expression_Constant($token
->getValue(), $token
->getLine());
}
elseif ($stream
->test(Twig_Token::PUNCTUATION_TYPE, '(')) {
$key = $this
->parseExpression();
}
else {
$current = $stream
->getCurrent();
throw new Twig_Error_Syntax(sprintf('A hash key must be a quoted string, a number, a name, or an expression enclosed in parentheses (unexpected token "%s" of value "%s".', Twig_Token::typeToEnglish($current
->getType()), $current
->getValue()), $current
->getLine(), $this->parser
->getFilename());
}
$stream
->expect(Twig_Token::PUNCTUATION_TYPE, ':', 'A hash key must be followed by a colon (:)');
$value = $this
->parseExpression();
$node
->addElement($value, $key);
}
$stream
->expect(Twig_Token::PUNCTUATION_TYPE, '}', 'An opened hash is not properly closed');
return $node;
}
public function parsePostfixExpression($node) {
while (true) {
$token = $this->parser
->getCurrentToken();
if ($token
->getType() == Twig_Token::PUNCTUATION_TYPE) {
if ('.' == $token
->getValue() || '[' == $token
->getValue()) {
$node = $this
->parseSubscriptExpression($node);
}
elseif ('|' == $token
->getValue()) {
$node = $this
->parseFilterExpression($node);
}
else {
break;
}
}
else {
break;
}
}
return $node;
}
public function getFunctionNode($name, $line) {
switch ($name) {
case 'parent':
$this
->parseArguments();
if (!count($this->parser
->getBlockStack())) {
throw new Twig_Error_Syntax('Calling "parent" outside a block is forbidden.', $line, $this->parser
->getFilename());
}
if (!$this->parser
->getParent() && !$this->parser
->hasTraits()) {
throw new Twig_Error_Syntax('Calling "parent" on a template that does not extend nor "use" another template is forbidden.', $line, $this->parser
->getFilename());
}
return new Twig_Node_Expression_Parent($this->parser
->peekBlockStack(), $line);
case 'block':
return new Twig_Node_Expression_BlockReference($this
->parseArguments()
->getNode(0), false, $line);
case 'attribute':
$args = $this
->parseArguments();
if (count($args) < 2) {
throw new Twig_Error_Syntax('The "attribute" function takes at least two arguments (the variable and the attributes).', $line, $this->parser
->getFilename());
}
return new Twig_Node_Expression_GetAttr($args
->getNode(0), $args
->getNode(1), count($args) > 2 ? $args
->getNode(2) : null, Twig_Template::ANY_CALL, $line);
default:
if (null !== ($alias = $this->parser
->getImportedSymbol('function', $name))) {
$arguments = new Twig_Node_Expression_Array(array(), $line);
foreach ($this
->parseArguments() as $n) {
$arguments
->addElement($n);
}
$node = new Twig_Node_Expression_MethodCall($alias['node'], $alias['name'], $arguments, $line);
$node
->setAttribute('safe', true);
return $node;
}
$args = $this
->parseArguments(true);
$class = $this
->getFunctionNodeClass($name, $line);
return new $class($name, $args, $line);
}
}
public function parseSubscriptExpression($node) {
$stream = $this->parser
->getStream();
$token = $stream
->next();
$lineno = $token
->getLine();
$arguments = new Twig_Node_Expression_Array(array(), $lineno);
$type = Twig_Template::ANY_CALL;
if ($token
->getValue() == '.') {
$token = $stream
->next();
if ($token
->getType() == Twig_Token::NAME_TYPE || $token
->getType() == Twig_Token::NUMBER_TYPE || $token
->getType() == Twig_Token::OPERATOR_TYPE && preg_match(Twig_Lexer::REGEX_NAME, $token
->getValue())) {
$arg = new Twig_Node_Expression_Constant($token
->getValue(), $lineno);
if ($stream
->test(Twig_Token::PUNCTUATION_TYPE, '(')) {
$type = Twig_TemplateInterface::METHOD_CALL;
foreach ($this
->parseArguments() as $n) {
$arguments
->addElement($n);
}
}
}
else {
throw new Twig_Error_Syntax('Expected name or number', $lineno, $this->parser
->getFilename());
}
if ($node instanceof Twig_Node_Expression_Name && null !== $this->parser
->getImportedSymbol('template', $node
->getAttribute('name'))) {
if (!$arg instanceof Twig_Node_Expression_Constant) {
throw new Twig_Error_Syntax(sprintf('Dynamic macro names are not supported (called on "%s").', $node
->getAttribute('name')), $token
->getLine(), $this->parser
->getFilename());
}
$name = $arg
->getAttribute('value');
if ($this->parser
->isReservedMacroName($name)) {
throw new Twig_Error_Syntax(sprintf('"%s" cannot be called as macro as it is a reserved keyword.', $name), $token
->getLine(), $this->parser
->getFilename());
}
$node = new Twig_Node_Expression_MethodCall($node, 'get' . $name, $arguments, $lineno);
$node
->setAttribute('safe', true);
return $node;
}
}
else {
$type = Twig_Template::ARRAY_CALL;
// slice?
$slice = false;
if ($stream
->test(Twig_Token::PUNCTUATION_TYPE, ':')) {
$slice = true;
$arg = new Twig_Node_Expression_Constant(0, $token
->getLine());
}
else {
$arg = $this
->parseExpression();
}
if ($stream
->nextIf(Twig_Token::PUNCTUATION_TYPE, ':')) {
$slice = true;
}
if ($slice) {
if ($stream
->test(Twig_Token::PUNCTUATION_TYPE, ']')) {
$length = new Twig_Node_Expression_Constant(null, $token
->getLine());
}
else {
$length = $this
->parseExpression();
}
$class = $this
->getFilterNodeClass('slice', $token
->getLine());
$arguments = new Twig_Node(array(
$arg,
$length,
));
$filter = new $class($node, new Twig_Node_Expression_Constant('slice', $token
->getLine()), $arguments, $token
->getLine());
$stream
->expect(Twig_Token::PUNCTUATION_TYPE, ']');
return $filter;
}
$stream
->expect(Twig_Token::PUNCTUATION_TYPE, ']');
}
return new Twig_Node_Expression_GetAttr($node, $arg, $arguments, $type, $lineno);
}
public function parseFilterExpression($node) {
$this->parser
->getStream()
->next();
return $this
->parseFilterExpressionRaw($node);
}
public function parseFilterExpressionRaw($node, $tag = null) {
while (true) {
$token = $this->parser
->getStream()
->expect(Twig_Token::NAME_TYPE);
$name = new Twig_Node_Expression_Constant($token
->getValue(), $token
->getLine());
if (!$this->parser
->getStream()
->test(Twig_Token::PUNCTUATION_TYPE, '(')) {
$arguments = new Twig_Node();
}
else {
$arguments = $this
->parseArguments(true);
}
$class = $this
->getFilterNodeClass($name
->getAttribute('value'), $token
->getLine());
$node = new $class($node, $name, $arguments, $token
->getLine(), $tag);
if (!$this->parser
->getStream()
->test(Twig_Token::PUNCTUATION_TYPE, '|')) {
break;
}
$this->parser
->getStream()
->next();
}
return $node;
}
/**
* Parses arguments.
*
* @param bool $namedArguments Whether to allow named arguments or not
* @param bool $definition Whether we are parsing arguments for a function definition
*
* @return Twig_Node
*
* @throws Twig_Error_Syntax
*/
public function parseArguments($namedArguments = false, $definition = false) {
$args = array();
$stream = $this->parser
->getStream();
$stream
->expect(Twig_Token::PUNCTUATION_TYPE, '(', 'A list of arguments must begin with an opening parenthesis');
while (!$stream
->test(Twig_Token::PUNCTUATION_TYPE, ')')) {
if (!empty($args)) {
$stream
->expect(Twig_Token::PUNCTUATION_TYPE, ',', 'Arguments must be separated by a comma');
}
if ($definition) {
$token = $stream
->expect(Twig_Token::NAME_TYPE, null, 'An argument must be a name');
$value = new Twig_Node_Expression_Name($token
->getValue(), $this->parser
->getCurrentToken()
->getLine());
}
else {
$value = $this
->parseExpression();
}
$name = null;
if ($namedArguments && ($token = $stream
->nextIf(Twig_Token::OPERATOR_TYPE, '='))) {
if (!$value instanceof Twig_Node_Expression_Name) {
throw new Twig_Error_Syntax(sprintf('A parameter name must be a string, "%s" given.', get_class($value)), $token
->getLine(), $this->parser
->getFilename());
}
$name = $value
->getAttribute('name');
if ($definition) {
$value = $this
->parsePrimaryExpression();
if (!$this
->checkConstantExpression($value)) {
throw new Twig_Error_Syntax(sprintf('A default value for an argument must be a constant (a boolean, a string, a number, or an array).'), $token
->getLine(), $this->parser
->getFilename());
}
}
else {
$value = $this
->parseExpression();
}
}
if ($definition) {
if (null === $name) {
$name = $value
->getAttribute('name');
$value = new Twig_Node_Expression_Constant(null, $this->parser
->getCurrentToken()
->getLine());
}
$args[$name] = $value;
}
else {
if (null === $name) {
$args[] = $value;
}
else {
$args[$name] = $value;
}
}
}
$stream
->expect(Twig_Token::PUNCTUATION_TYPE, ')', 'A list of arguments must be closed by a parenthesis');
return new Twig_Node($args);
}
public function parseAssignmentExpression() {
$targets = array();
while (true) {
$token = $this->parser
->getStream()
->expect(Twig_Token::NAME_TYPE, null, 'Only variables can be assigned to');
if (in_array($token
->getValue(), array(
'true',
'false',
'none',
))) {
throw new Twig_Error_Syntax(sprintf('You cannot assign a value to "%s".', $token
->getValue()), $token
->getLine(), $this->parser
->getFilename());
}
$targets[] = new Twig_Node_Expression_AssignName($token
->getValue(), $token
->getLine());
if (!$this->parser
->getStream()
->nextIf(Twig_Token::PUNCTUATION_TYPE, ',')) {
break;
}
}
return new Twig_Node($targets);
}
public function parseMultitargetExpression() {
$targets = array();
while (true) {
$targets[] = $this
->parseExpression();
if (!$this->parser
->getStream()
->nextIf(Twig_Token::PUNCTUATION_TYPE, ',')) {
break;
}
}
return new Twig_Node($targets);
}
protected function getFunctionNodeClass($name, $line) {
$env = $this->parser
->getEnvironment();
if (false === ($function = $env
->getFunction($name))) {
$e = new Twig_Error_Syntax(sprintf('Unknown "%s" function.', $name), $line, $this->parser
->getFilename());
$e
->addSuggestions($name, array_keys($env
->getFunctions()));
throw $e;
}
if ($function instanceof Twig_SimpleFunction && $function
->isDeprecated()) {
$message = sprintf('Twig Function "%s" is deprecated', $function
->getName());
if ($function
->getAlternative()) {
$message .= sprintf('. Use "%s" instead', $function
->getAlternative());
}
$message .= sprintf(' in %s at line %d.', $this->parser
->getFilename(), $line);
@trigger_error($message, E_USER_DEPRECATED);
}
if ($function instanceof Twig_SimpleFunction) {
return $function
->getNodeClass();
}
return $function instanceof Twig_Function_Node ? $function
->getClass() : 'Twig_Node_Expression_Function';
}
protected function getFilterNodeClass($name, $line) {
$env = $this->parser
->getEnvironment();
if (false === ($filter = $env
->getFilter($name))) {
$e = new Twig_Error_Syntax(sprintf('Unknown "%s" filter.', $name), $line, $this->parser
->getFilename());
$e
->addSuggestions($name, array_keys($env
->getFilters()));
throw $e;
}
if ($filter instanceof Twig_SimpleFilter && $filter
->isDeprecated()) {
$message = sprintf('Twig Filter "%s" is deprecated', $filter
->getName());
if ($filter
->getAlternative()) {
$message .= sprintf('. Use "%s" instead', $filter
->getAlternative());
}
$message .= sprintf(' in %s at line %d.', $this->parser
->getFilename(), $line);
@trigger_error($message, E_USER_DEPRECATED);
}
if ($filter instanceof Twig_SimpleFilter) {
return $filter
->getNodeClass();
}
return $filter instanceof Twig_Filter_Node ? $filter
->getClass() : 'Twig_Node_Expression_Filter';
}
// checks that the node only contains "constant" elements
protected function checkConstantExpression(Twig_NodeInterface $node) {
if (!($node instanceof Twig_Node_Expression_Constant || $node instanceof Twig_Node_Expression_Array || $node instanceof Twig_Node_Expression_Unary_Neg || $node instanceof Twig_Node_Expression_Unary_Pos)) {
return false;
}
foreach ($node as $n) {
if (!$this
->checkConstantExpression($n)) {
return false;
}
}
return true;
}
}