Package org.antlr.runtime.tree

Class RewriteRuleSubtreeStream

java.lang.Object

org.antlr.runtime.tree.RewriteRuleElementStream

org.antlr.runtime.tree.RewriteRuleSubtreeStream

public class RewriteRuleSubtreeStream
extends RewriteRuleElementStream

Field Summary

Fields inherited from class org.antlr.runtime.tree.RewriteRuleElementStream

adaptor, cursor, dirty, elementDescription, elements, singleElement

Constructor Summary

Constructors

Constructor	Description
RewriteRuleSubtreeStream(TreeAdaptor adaptor, String elementDescription)
RewriteRuleSubtreeStream(TreeAdaptor adaptor, String elementDescription, Object oneElement)	Create a stream with one element
RewriteRuleSubtreeStream(TreeAdaptor adaptor, String elementDescription, List<Object> elements)	Create a stream, but feed off an existing list

Method Summary

Modifier and Type	Method	Description
protected Object	dup(Object el)	When constructing trees, sometimes we need to dup a token or AST subtree.
Object	nextNode()	Treat next element as a single node even if it's a subtree.

Methods inherited from class org.antlr.runtime.tree.RewriteRuleElementStream

_next, add, getDescription, hasNext, nextTree, reset, size, toTree

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RewriteRuleSubtreeStream

public RewriteRuleSubtreeStream(TreeAdaptor adaptor,
                                String elementDescription)

RewriteRuleSubtreeStream

public RewriteRuleSubtreeStream(TreeAdaptor adaptor,
                                String elementDescription,
                                Object oneElement)

Create a stream with one element

RewriteRuleSubtreeStream

public RewriteRuleSubtreeStream(TreeAdaptor adaptor,
                                String elementDescription,
                                List<Object> elements)

Create a stream, but feed off an existing list

Method Detail

nextNode

public Object nextNode()

Treat next element as a single node even if it's a subtree. This is used instead of next() when the result has to be a tree root node. Also prevents us from duplicating recently-added children; e.g., ^(type ID)+ adds ID to type and then 2nd iteration must dup the type node, but ID has been added. Referencing a rule result twice is ok; dup entire tree as we can't be adding trees as root; e.g., expr expr. Hideous code duplication here with super.next(). Can't think of a proper way to refactor. This needs to always call dup node and super.next() doesn't know which to call: dup node or dup tree.

dup

protected Object dup(Object el)

Description copied from class: RewriteRuleElementStream

When constructing trees, sometimes we need to dup a token or AST subtree. Dup'ing a token means just creating another AST node around it. For trees, you must call the adaptor.dupTree() unless the element is for a tree root; then it must be a node dup.

Specified by:

dup in class RewriteRuleElementStream