io.jenetics.ext.rewriting

Interface TreeRewriter<V>

All Known Implementing Classes:

TreeRewriteRule, TRS

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface TreeRewriter<V>

Interface for rewriting a given tree. The rewrite is performed on a mutable TreeNode and is done in place.

Description from Wikipedia: In mathematics, computer science, and logic, rewriting covers a wide range of (potentially non-deterministic) methods of replacing sub-terms of a formula with other terms. In their most basic form, they consist of a set of objects, plus relations on how to transform those objects. Rewriting can be non-deterministic. One rule to rewrite a term could be applied in many different ways to that term, or more than one rule could be applicable. Rewriting systems then do not provide an algorithm for changing one term to another, but a set of possible rule applications. When combined with an appropriate algorithm, however, rewrite systems can be viewed as computer programs, and several theorem provers and declarative programming languages are based on term rewriting.

Since:

5.0

Version:

5.0

Author:

Franz Wilhelmstötter

API Note:

The rewriting is done in place, to a mutable TreeNode object.

Method Summary

Modifier and Type	Method and Description
static <V> TreeRewriter<V>	concat(TreeRewriter<V>... rewriters) Concat the given rewriters to one tree-rewriter.
default int	rewrite(TreeNode<V> tree) Applies the rewriting to the given (mutable) tree.
int	rewrite(TreeNode<V> tree, int limit) Applies the rewriting to the given (mutable) tree.
static <V> int	rewrite(TreeNode<V> tree, int limit, Iterable<? extends TreeRewriter<V>> rewriters) Rewrites the given tree by applying the given rewriters.
static <V> int	rewrite(TreeNode<V> tree, Iterable<? extends TreeRewriter<V>> rewriters) Rewrites the given tree by applying the given rewriters.

Method Detail

rewrite

int rewrite(TreeNode<V> tree,
            int limit)

Applies the rewriting to the given (mutable) tree. The tree rewrite is done in place. Via the limit parameter, the termination of the tree-rewrite process can be guaranteed.

Parameters:

tree - the tree to be rewritten

limit - the maximal number this rewrite rule is applied to the given tree. This guarantees the termination of the rewrite method.

Returns:

the number of rewrites applied to the input tree

Throws:

NullPointerException - if the given tree is null

IllegalArgumentException - if the limit is smaller than one

rewrite

default int rewrite(TreeNode<V> tree)

Applies the rewriting to the given (mutable) tree. The tree rewrite is done in place. The limit of the applied rewrites is set unlimited (Integer.MAX_VALUE).

Parameters:

tree - the tree to be rewritten

Returns:

true if the tree has been changed (rewritten) by this method, false if the tree hasn't been changed

Throws:

NullPointerException - if the given tree is null

See Also:

rewrite(TreeNode, int)

rewrite

static <V> int rewrite(TreeNode<V> tree,
                       int limit,
                       Iterable<? extends TreeRewriter<V>> rewriters)

Rewrites the given tree by applying the given rewriters. This method to apply the all rewriters, in the order they are given in the sequence, until the tree stays unchanged.

Type Parameters:

V - the tree value type

Parameters:

tree - the tree to rewrite

limit - the maximal number this rewrite rule is applied to the given tree. This guarantees the termination of the rewrite method.

rewriters - the rewriters applied to the tree

Returns:

true if the tree has been changed (rewritten) by this method, false if the tree hasn't been changed

Throws:

NullPointerException - if one of the arguments is null

IllegalArgumentException - if the limit is smaller than zero

rewrite

static <V> int rewrite(TreeNode<V> tree,
                       Iterable<? extends TreeRewriter<V>> rewriters)

Rewrites the given tree by applying the given rewriters. This method to apply the all rewriters, in the order they are given in the sequence, until the tree stays unchanged.

Type Parameters:

V - the tree value type

Parameters:

tree - the tree to rewrite

rewriters - the rewriters applied to the tree

Returns:

true if the tree has been changed (rewritten) by this method, false if the tree hasn't been changed

Throws:

NullPointerException - if one of the arguments is null

See Also:

rewrite(TreeNode, int, Iterable)

concat

@SafeVarargs
static <V> TreeRewriter<V> concat(TreeRewriter<V>... rewriters)

Concat the given rewriters to one tree-rewriter.

Type Parameters:

V - the tree value type

Parameters:

rewriters - the tree-rewriter to concatenate

Returns:

a new tree-rewriter which concatenates the given one

Throws:

NullPointerException - if the given rewriters are null

IllegalArgumentException - if the limit is smaller than zero