--- /dev/null
+<?php
+/*
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the MIT license. For more information, see
+ * <http://www.doctrine-project.org>.
+ */
+
+namespace Doctrine\Common\Collections\Expr;
+
+/**
+ * Comparison of a field with a value by the given operator.
+ *
+ * @author Benjamin Eberlei <kontakt@beberlei.de>
+ * @since 2.3
+ */
+class Comparison implements Expression
+{
+ const EQ = '=';
+ const NEQ = '<>';
+ const LT = '<';
+ const LTE = '<=';
+ const GT = '>';
+ const GTE = '>=';
+ const IS = '='; // no difference with EQ
+ const IN = 'IN';
+ const NIN = 'NIN';
+ const CONTAINS = 'CONTAINS';
+
+ /**
+ * @var string
+ */
+ private $field;
+
+ /**
+ * @var string
+ */
+ private $op;
+
+ /**
+ * @var Value
+ */
+ private $value;
+
+ /**
+ * @param string $field
+ * @param string $operator
+ * @param mixed $value
+ */
+ public function __construct($field, $operator, $value)
+ {
+ if ( ! ($value instanceof Value)) {
+ $value = new Value($value);
+ }
+
+ $this->field = $field;
+ $this->op = $operator;
+ $this->value = $value;
+ }
+
+ /**
+ * @return string
+ */
+ public function getField()
+ {
+ return $this->field;
+ }
+
+ /**
+ * @return Value
+ */
+ public function getValue()
+ {
+ return $this->value;
+ }
+
+ /**
+ * @return string
+ */
+ public function getOperator()
+ {
+ return $this->op;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public function visit(ExpressionVisitor $visitor)
+ {
+ return $visitor->walkComparison($this);
+ }
+}