Class ExpressionTraverser

You can attach Webmozart\Expression\Traversal\ExpressionVisitor instances to the traverse which will be invoked for every node of the expression tree.

Namespace: Webmozart\Expression\Traversal
Author: Bernhard Schussek bschussek@gmail.com
Since: 1.0
Located at Traversal/ExpressionTraverser.php

Methods summary
`public`	# `addVisitor( Webmozart\Expression\Traversal\ExpressionVisitor $visitor )` Adds a visitor to the traverser. Adds a visitor to the traverser. The visitors are invoked in the order in which they are added. Parameters `$visitor` The visitor to add.
`public`	# `removeVisitor( Webmozart\Expression\Traversal\ExpressionVisitor $visitor )` Removes a visitor from the traverser. Removes a visitor from the traverser. If the visitor was added multiple times, all instances are removed. Parameters `$visitor` The visitor to remove.
`public Webmozart\Expression\Traversal\ExpressionVisitor[]`	# `getVisitors( )` Returns the visitors of the traverser. Returns the visitors of the traverser. Returns `Webmozart\Expression\Traversal\ExpressionVisitor[]` The visitors.
`public Webmozart\Expression\Expression`	# `traverse( Webmozart\Expression\Expression $expr )` Traverses an expression. Traverses an expression. Parameters `$expr` The expression to traverse. Returns `Webmozart\Expression\Expression` The modified expression. May be `null` if the expression was removed entirely.