Version 1

[yaffs-website] / vendor / symfony / expression-language / ExpressionLanguage.php

diff --git a/vendor/symfony/expression-language/ExpressionLanguage.php b/vendor/symfony/expression-language/ExpressionLanguage.php
new file mode 100644 (file)
index 0000000..444b59a
--- /dev/null
+++ b/vendor/symfony/expression-language/ExpressionLanguage.php
@@ -0,0 +1,173 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\ExpressionLanguage;
+
+use Symfony\Component\ExpressionLanguage\ParserCache\ArrayParserCache;
+use Symfony\Component\ExpressionLanguage\ParserCache\ParserCacheInterface;
+
+/**
+ * Allows to compile and evaluate expressions written in your own DSL.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class ExpressionLanguage
+{
+    /**
+     * @var ParserCacheInterface
+     */
+    private $cache;
+    private $lexer;
+    private $parser;
+    private $compiler;
+
+    protected $functions = array();
+
+    /**
+     * @param ParserCacheInterface                  $cache
+     * @param ExpressionFunctionProviderInterface[] $providers
+     */
+    public function __construct(ParserCacheInterface $cache = null, array $providers = array())
+    {
+        $this->cache = $cache ?: new ArrayParserCache();
+        $this->registerFunctions();
+        foreach ($providers as $provider) {
+            $this->registerProvider($provider);
+        }
+    }
+
+    /**
+     * Compiles an expression source code.
+     *
+     * @param Expression|string $expression The expression to compile
+     * @param array             $names      An array of valid names
+     *
+     * @return string The compiled PHP source code
+     */
+    public function compile($expression, $names = array())
+    {
+        return $this->getCompiler()->compile($this->parse($expression, $names)->getNodes())->getSource();
+    }
+
+    /**
+     * Evaluate an expression.
+     *
+     * @param Expression|string $expression The expression to compile
+     * @param array             $values     An array of values
+     *
+     * @return string The result of the evaluation of the expression
+     */
+    public function evaluate($expression, $values = array())
+    {
+        return $this->parse($expression, array_keys($values))->getNodes()->evaluate($this->functions, $values);
+    }
+
+    /**
+     * Parses an expression.
+     *
+     * @param Expression|string $expression The expression to parse
+     * @param array             $names      An array of valid names
+     *
+     * @return ParsedExpression A ParsedExpression instance
+     */
+    public function parse($expression, $names)
+    {
+        if ($expression instanceof ParsedExpression) {
+            return $expression;
+        }
+
+        asort($names);
+        $cacheKeyItems = array();
+
+        foreach ($names as $nameKey => $name) {
+            $cacheKeyItems[] = is_int($nameKey) ? $name : $nameKey.':'.$name;
+        }
+
+        $key = $expression.'//'.implode('|', $cacheKeyItems);
+
+        if (null === $parsedExpression = $this->cache->fetch($key)) {
+            $nodes = $this->getParser()->parse($this->getLexer()->tokenize((string) $expression), $names);
+            $parsedExpression = new ParsedExpression((string) $expression, $nodes);
+
+            $this->cache->save($key, $parsedExpression);
+        }
+
+        return $parsedExpression;
+    }
+
+    /**
+     * Registers a function.
+     *
+     * @param string   $name      The function name
+     * @param callable $compiler  A callable able to compile the function
+     * @param callable $evaluator A callable able to evaluate the function
+     *
+     * @throws \LogicException when registering a function after calling evaluate(), compile() or parse()
+     *
+     * @see ExpressionFunction
+     */
+    public function register($name, $compiler, $evaluator)
+    {
+        if (null !== $this->parser) {
+            throw new \LogicException('Registering functions after calling evaluate(), compile() or parse() is not supported.');
+        }
+
+        $this->functions[$name] = array('compiler' => $compiler, 'evaluator' => $evaluator);
+    }
+
+    public function addFunction(ExpressionFunction $function)
+    {
+        $this->register($function->getName(), $function->getCompiler(), $function->getEvaluator());
+    }
+
+    public function registerProvider(ExpressionFunctionProviderInterface $provider)
+    {
+        foreach ($provider->getFunctions() as $function) {
+            $this->addFunction($function);
+        }
+    }
+
+    protected function registerFunctions()
+    {
+        $this->register('constant', function ($constant) {
+            return sprintf('constant(%s)', $constant);
+        }, function (array $values, $constant) {
+            return constant($constant);
+        });
+    }
+
+    private function getLexer()
+    {
+        if (null === $this->lexer) {
+            $this->lexer = new Lexer();
+        }
+
+        return $this->lexer;
+    }
+
+    private function getParser()
+    {
+        if (null === $this->parser) {
+            $this->parser = new Parser($this->functions);
+        }
+
+        return $this->parser;
+    }
+
+    private function getCompiler()
+    {
+        if (null === $this->compiler) {
+            $this->compiler = new Compiler($this->functions);
+        }
+
+        return $this->compiler->reset();
+    }
+}