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Diffstat (limited to '')
-rw-r--r-- | vendor/doctrine/collections/lib/Doctrine/Common/Collections/Expr/ExpressionVisitor.php | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/vendor/doctrine/collections/lib/Doctrine/Common/Collections/Expr/ExpressionVisitor.php b/vendor/doctrine/collections/lib/Doctrine/Common/Collections/Expr/ExpressionVisitor.php new file mode 100644 index 0000000..72bb153 --- /dev/null +++ b/vendor/doctrine/collections/lib/Doctrine/Common/Collections/Expr/ExpressionVisitor.php @@ -0,0 +1,59 @@ +<?php + +namespace Doctrine\Common\Collections\Expr; + +use RuntimeException; + +use function get_class; + +/** + * An Expression visitor walks a graph of expressions and turns them into a + * query for the underlying implementation. + */ +abstract class ExpressionVisitor +{ + /** + * Converts a comparison expression into the target query language output. + * + * @return mixed + */ + abstract public function walkComparison(Comparison $comparison); + + /** + * Converts a value expression into the target query language part. + * + * @return mixed + */ + abstract public function walkValue(Value $value); + + /** + * Converts a composite expression into the target query language output. + * + * @return mixed + */ + abstract public function walkCompositeExpression(CompositeExpression $expr); + + /** + * Dispatches walking an expression to the appropriate handler. + * + * @return mixed + * + * @throws RuntimeException + */ + public function dispatch(Expression $expr) + { + switch (true) { + case $expr instanceof Comparison: + return $this->walkComparison($expr); + + case $expr instanceof Value: + return $this->walkValue($expr); + + case $expr instanceof CompositeExpression: + return $this->walkCompositeExpression($expr); + + default: + throw new RuntimeException('Unknown Expression ' . get_class($expr)); + } + } +} |