Better config validation handling for numerical values:

 * New node type Integer and Float
 * New expressions: min() and max()

src/Symfony/Component/Config/Definition/Builder/FloatNodeDefinition.php

@@ -0,0 +1,32 @@
+<?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\Config\Definition\Builder;
+
+use Symfony\Component\Config\Definition\FloatNode;
+
+/**
+ * This class provides a fluent interface for defining a float node.
+ *
+ * @author Jeanmonod David <david.jeanmonod@gmail.com>
+ */
+class FloatNodeDefinition extends NumericNodeDefinition
+{
+    /**
+     * Instantiate a Node
+     *
+     * @return FloatNode The node
+     */
+    protected function instantiateNode()
+    {
+        return new FloatNode($this->name, $this->parent, $this->min, $this->max);
+    }
+}

src/Symfony/Component/Config/Definition/Builder/IntegerNodeDefinition.php

@@ -0,0 +1,32 @@
+<?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\Config\Definition\Builder;
+
+use Symfony\Component\Config\Definition\IntegerNode;
+
+/**
+ * This class provides a fluent interface for defining an integer node.
+ *
+ * @author Jeanmonod David <david.jeanmonod@gmail.com>
+ */
+class IntegerNodeDefinition extends NumericNodeDefinition
+{
+    /**
+     * Instantiate a Node
+     *
+     * @return IntegerNode The node
+     */
+    protected function instantiateNode()
+    {
+        return new IntegerNode($this->name, $this->parent, $this->min, $this->max);
+    }
+}

src/Symfony/Component/Config/Definition/Builder/NodeBuilder.php

@@ -31,6 +31,8 @@ public function __construct()
             'variable'    => __NAMESPACE__.'\\VariableNodeDefinition',
             'scalar'      => __NAMESPACE__.'\\ScalarNodeDefinition',
             'boolean'     => __NAMESPACE__.'\\BooleanNodeDefinition',
+            'integer'     => __NAMESPACE__.'\\IntegerNodeDefinition',
+            'float'       => __NAMESPACE__.'\\FloatNodeDefinition',
             'array'       => __NAMESPACE__.'\\ArrayNodeDefinition',
             'enum'        => __NAMESPACE__.'\\EnumNodeDefinition',
         );
@@ -86,6 +88,30 @@ public function booleanNode($name)
         return $this->node($name, 'boolean');
     }
 
+    /**
+     * Creates a child integer node.
+     *
+     * @param string $name the name of the node
+     *
+     * @return IntegerNodeDefinition The child node
+     */
+    public function integerNode($name)
+    {
+        return $this->node($name, 'integer');
+    }
+
+    /**
+     * Creates a child float node.
+     *
+     * @param string $name the name of the node
+     *
+     * @return FloatNodeDefinition The child node
+     */
+    public function floatNode($name)
+    {
+        return $this->node($name, 'float');
+    }
+
     /**
      * Creates a child EnumNode.
      *

src/Symfony/Component/Config/Definition/Builder/NumericNodeDefinition.php

@@ -0,0 +1,58 @@
+<?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\Config\Definition\Builder;
+
+/**
+ * Abstract class that contain common code of integer and float node definition.
+ *
+ * @author David Jeanmonod <david.jeanmonod@gmail.com>
+ */
+abstract class NumericNodeDefinition extends ScalarNodeDefinition
+{
+
+    protected $min;
+    protected $max;
+
+    /**
+     * Ensure the value is smaller than the given reference
+     *
+     * @param mixed $max
+     *
+     * @return NumericNodeDefinition
+     */
+    public function max($max)
+    {
+        if (isset($this->min) && $this->min > $max) {
+            throw new \InvalidArgumentException(sprintf('You cannot define a max(%s) as you already have a min(%s)', $max, $this->min));
+        }
+        $this->max = $max;
+
+        return $this;
+    }
+
+    /**
+     * Ensure the value is bigger than the given reference
+     *
+     * @param mixed $min
+     *
+     * @return NumericNodeDefinition
+     */
+    public function min($min)
+    {
+        if (isset($this->max) && $this->max < $min) {
+            throw new \InvalidArgumentException(sprintf('You cannot define a min(%s) as you already have a max(%s)', $min, $this->max));
+        }
+        $this->min = $min;
+
+        return $this;
+    }
+}

src/Symfony/Component/Config/Definition/FloatNode.php

@@ -0,0 +1,44 @@
+<?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\Config\Definition;
+
+use Symfony\Component\Config\Definition\Exception\InvalidTypeException;
+
+/**
+ * This node represents a float value in the config tree.
+ *
+ * @author Jeanmonod David <david.jeanmonod@gmail.com>
+ */
+class FloatNode extends NumericNode
+{
+    /**
+     * {@inheritDoc}
+     */
+    protected function validateType($value)
+    {
+        // Integers are also accepted, we just cast them
+        if (is_int($value)) {
+            $value = (float) $value;
+        }
+
+        if (!is_float($value)) {
+            $ex = new InvalidTypeException(sprintf(
+                'Invalid type for path "%s". Expected float, but got %s.',
+                $this->getPath(),
+                gettype($value)
+            ));
+            $ex->setPath($this->getPath());
+
+            throw $ex;
+        }
+    }
+}

src/Symfony/Component/Config/Definition/IntegerNode.php

@@ -0,0 +1,39 @@
+<?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\Config\Definition;
+
+use Symfony\Component\Config\Definition\Exception\InvalidTypeException;
+
+/**
+ * This node represents an integer value in the config tree.
+ *
+ * @author Jeanmonod David <david.jeanmonod@gmail.com>
+ */
+class IntegerNode extends NumericNode
+{
+    /**
+     * {@inheritDoc}
+     */
+    protected function validateType($value)
+    {
+        if (!is_int($value)) {
+            $ex = new InvalidTypeException(sprintf(
+                'Invalid type for path "%s". Expected int, but got %s.',
+                $this->getPath(),
+                gettype($value)
+            ));
+            $ex->setPath($this->getPath());
+
+            throw $ex;
+        }
+    }
+}

src/Symfony/Component/Config/Definition/NumericNode.php

@@ -0,0 +1,56 @@
+<?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\Config\Definition;
+
+use Symfony\Component\Config\Definition\Exception\InvalidConfigurationException;
+
+/**
+ * This node represents a numeric value in the config tree
+ *
+ * @author David Jeanmonod <david.jeanmonod@gmail.com>
+ */
+class NumericNode extends ScalarNode
+{
+    protected $min;
+    protected $max;
+
+    public function __construct($name, NodeInterface $parent = null, $min = null, $max = null)
+    {
+        parent::__construct($name, $parent);
+        $this->min = $min;
+        $this->max = $max;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    protected function finalizeValue($value)
+    {
+        $value = parent::finalizeValue($value);
+
+        $errorMsg = null;
+        if (isset($this->min) && $value < $this->min) {
+            $errorMsg = sprintf('The value %s is too small for path "%s". Should be greater than: %s', $value, $this->getPath(), $this->min);
+        }
+        if (isset($this->max) && $value > $this->max) {
+            $errorMsg = sprintf('The value %s is too big for path "%s". Should be less than: %s', $value, $this->getPath(), $this->max);
+        }
+        if (isset($errorMsg)) {
+            $ex = new InvalidConfigurationException($errorMsg);
+            $ex->setPath($this->getPath());
+            throw $ex;
+        }
+
+        return $value;
+    }
+
+}

src/Symfony/Component/Config/Tests/Definition/Builder/ExprBuilderTest.php

@@ -13,7 +13,6 @@
 
 use Symfony\Component\Config\Definition\Builder\TreeBuilder;
 
-
 class ExprBuilderTest extends \PHPUnit_Framework_TestCase
 {
 
@@ -160,6 +159,7 @@ public function testThenUnsetExpression()
     protected function getTestBuilder()
     {
         $builder = new TreeBuilder();
+
         return $builder
             ->root('test')
             ->children()
@@ -171,7 +171,7 @@ protected function getTestBuilder()
     /**
      * Close the validation process and finalize with the given config
      * @param TreeBuilder $testBuilder The tree builder to finalize
-     * @param array $config The config you want to use for the finalization, if nothing provided
+     * @param array       $config      The config you want to use for the finalization, if nothing provided
      *                       a simple array('key'=>'value') will be used
      * @return array The finalized config values
      */
@@ -191,17 +191,18 @@ protected function finalizeTestBuilder($testBuilder, $config=null)
      * @param $val The value that the closure must return
      * @return Closure
      */
-    protected function returnClosure($val) {
+    protected function returnClosure($val)
+    {
         return function($v) use ($val) {
             return $val;
         };
     }
 
     /**
      * Assert that the given test builder, will return the given value
-     * @param mixed $value      The value to test
-     * @param TreeBuilder $test The tree builder to finalize
-     * @param mixed $config     The config values that new to be finalized
+     * @param mixed       $value  The value to test
+     * @param TreeBuilder $test   The tree builder to finalize
+     * @param mixed       $config The config values that new to be finalized
      */
     protected function assertFinalizedValueIs($value, $treeBuilder, $config=null)
     {

src/Symfony/Component/Config/Tests/Definition/Builder/NodeBuilderTest.php

@@ -76,6 +76,17 @@ public function testNodeTypesAreNotCaseSensitive()
 
         $this->assertEquals(get_class($node1), get_class($node2));
     }
+
+    public function testNumericNodeCreation()
+    {
+        $builder = new NodeBuilder();
+
+        $node = $builder->integerNode('foo')->min(3)->max(5);
+        $this->assertEquals('Symfony\Component\Config\Definition\Builder\IntegerNodeDefinition', get_class($node));
+
+        $node = $builder->floatNode('bar')->min(3.0)->max(5.0);
+        $this->assertEquals('Symfony\Component\Config\Definition\Builder\FloatNodeDefinition', get_class($node));
+    }
 }
 
 class SomeNodeDefinition extends BaseVariableNodeDefinition