xtc.parser

Class TreeExtractor

java.lang.Object

xtc.tree.Visitor

xtc.parser.TreeExtractor

public class TreeExtractor
extends Visitor

Visitor to pear down a grammar to the structure of its abstract syntax tree. This visitor assumes that the entire grammar is contained in a single module. It also assumes that directly left-recursive generic productions have not been transformed by DirectLeftRecurser. Note that, after this visitor has processed the grammar, the grammar violates the code generator's requirements. Also note that this visitor internally uses Simplifier and DeadProductionEliminator.

Version:

$Revision: 1.11 $

Author:

Robert Grimm

Field Summary

Fields

Modifier and Type	Field and Description
protected Analyzer	analyzer The analyzer utility.
protected AST	ast The common type operations.
protected boolean	isGeneric The flag for whether the current production is generic.
protected boolean	isList The flag for whether the current production is list-valued.
protected boolean	isTextOnly The flag for whether the current production is text-only.
protected boolean	isToken The flag for whether the current production is token-level.
protected boolean	keepLexical The flag for removing all elements from lexical productions.
protected Runtime	runtime The runtime.
protected boolean	setsValue The flag for whether the current production defines the semantic value in an explicit action.

Constructor Summary

Constructors

Constructor and Description
TreeExtractor(Runtime runtime, Analyzer analyzer, AST ast, boolean keepLexical) Create a new tree extractor.

Method Summary

Methods

Modifier and Type	Method and Description
void	visit(CharCase c) Visit the specified character case.
void	visit(CharSwitch s) Visit the specified character switch.
void	visit(Element e) Visit the specified element.
void	visit(FullProduction p) Visit the specified full production.
void	visit(Module m) Visit the specified module.
void	visit(OrderedChoice c) Visit the specified ordered choice.
void	visit(Sequence s) Visit the specified sequence.
void	visit(UnaryOperator op) Visit the specified unary operator.

Methods inherited from class xtc.tree.Visitor

dispatch, equals, hashCode, iterate, map, mapInPlace, unableToVisit, visit

Methods inherited from class java.lang.Object

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

Field Detail

runtime

protected final Runtime runtime

The runtime.

analyzer

protected final Analyzer analyzer

The analyzer utility.

ast

protected final AST ast

The common type operations.

keepLexical

protected final boolean keepLexical

The flag for removing all elements from lexical productions.

isGeneric

protected boolean isGeneric

The flag for whether the current production is generic.

isList

protected boolean isList

The flag for whether the current production is list-valued.

isTextOnly

protected boolean isTextOnly

The flag for whether the current production is text-only.

isToken

protected boolean isToken

The flag for whether the current production is token-level.

setsValue

protected boolean setsValue

The flag for whether the current production defines the semantic value in an explicit action.

Constructor Detail

TreeExtractor

public TreeExtractor(Runtime runtime,
             Analyzer analyzer,
             AST ast,
             boolean keepLexical)

Create a new tree extractor.

Parameters:

runtime - The runtime.

analyzer - The analyzer utility.

ast - The type operations.

keepLexical - The flag for keeping elements of text-only or token-level productions.

Method Detail

visit

public void visit(Module m)

Visit the specified module.

visit

public void visit(FullProduction p)

Visit the specified full production.

visit

public void visit(OrderedChoice c)

Visit the specified ordered choice.

visit

public void visit(Sequence s)

Visit the specified sequence.

visit

public void visit(CharCase c)

Visit the specified character case.

visit

public void visit(CharSwitch s)

Visit the specified character switch.

visit

public void visit(UnaryOperator op)

Visit the specified unary operator.

visit

public void visit(Element e)

Visit the specified element.