xtc.parser
Class EquivalenceTester

java.lang.Object
  xtc.tree.Visitor
      xtc.parser.EquivalenceTester

public class EquivalenceTester
extends Visitor

Visitor to test productions and elements for equivalence. This visitor tests whether two productions or two elements are structurally the same, modulo using different variable names and having different nonterminals (for productions). It should only be invoked through the areEquivalent(Production,Production) and areEquivalent(Element,Element) methods.

Version:

$Revision: 1.36 $

Author:

Robert Grimm

Field Summary

protected Element	e2 The element to compare to.
protected java.util.Map<java.lang.String,java.lang.String>	nts The mapping between equivalent nonterminals.
protected java.util.Map<java.lang.String,java.lang.String>	vars The mapping between equivalent variables.

Constructor Summary

EquivalenceTester()
Create a new equivalence tester.

Method Summary

boolean	areEquivalent(Element e1, Element e2) Determine whether the specified elements are equivalent.
protected boolean	areEquivalent(GenericValue v1, GenericValue v2) Determine whether the specified generic values are equivalent.
protected boolean	areEquivalent(java.util.List<Binding> l1, java.util.List<Binding> l2) Determine whether the specified lists of bindings are equivalent.
boolean	areEquivalent(Production p1, Production p2) Determine whether the specified productions are equivalent.
java.lang.Boolean	visit(ActionBaseValue v1) Visit the specified action base value.
java.lang.Boolean	visit(Binding b1) Visit the specified binding.
java.lang.Boolean	visit(BindingValue v1) Visit the specified binding value.
java.lang.Boolean	visit(CharSwitch s1) Visit the specified character switch.
java.lang.Boolean	visit(Element e1) Visit the specified element.
java.lang.Boolean	visit(GenericActionValue v1) Visit the specified generic action value.
java.lang.Boolean	visit(GenericNodeValue v1) Visit the specified generic node value.
java.lang.Boolean	visit(GenericRecursionValue v1) Visit the specified generic recursion value.
java.lang.Boolean	visit(NonTerminal nt1) Visit the specified nonterminal.
java.lang.Boolean	visit(OrderedChoice c1) Visit the specified ordered choice.
java.lang.Boolean	visit(ParseTreeNode n1) Visit the specified parse tree node.
java.lang.Boolean	visit(ProperListValue v1) Visit the specified proper list value.
java.lang.Boolean	visit(Repetition r1) Visit the specified repetition.
java.lang.Boolean	visit(Sequence s1) Visit the specified sequence.
java.lang.Boolean	visit(StringMatch m1) Visit the specified string match.
java.lang.Boolean	visit(UnaryOperator op1) 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

nts

protected java.util.Map<java.lang.String,java.lang.String> nts

The mapping between equivalent nonterminals.

vars

protected java.util.Map<java.lang.String,java.lang.String> vars

The mapping between equivalent variables.

e2

protected Element e2

The element to compare to.

Constructor Detail

EquivalenceTester

public EquivalenceTester()

Create a new equivalence tester.

Method Detail

areEquivalent

public boolean areEquivalent(Production p1,
                             Production p2)

Determine whether the specified productions are equivalent.

Parameters:

p1 - The first production.

p2 - The second production.

Returns:

true if the two productions are equivalent.

areEquivalent

public boolean areEquivalent(Element e1,
                             Element e2)

Determine whether the specified elements are equivalent.

Parameters:

e1 - The first element.

e2 - The second element.

Returns:

true if the two elements are equivalent.

areEquivalent

protected boolean areEquivalent(java.util.List<Binding> l1,
                                java.util.List<Binding> l2)

Determine whether the specified lists of bindings are equivalent.

Parameters:

l1 - The first list.

l2 - The second list.

Returns:

true if the two lists are equivalent.

areEquivalent

protected boolean areEquivalent(GenericValue v1,
                                GenericValue v2)

Determine whether the specified generic values are equivalent.

Parameters:

v1 - The first value.

v2 - The second value.

Returns:

true if the two values are equivalent.

visit

public java.lang.Boolean visit(OrderedChoice c1)

Visit the specified ordered choice.

visit

public java.lang.Boolean visit(Repetition r1)

Visit the specified repetition.

visit

public java.lang.Boolean visit(Sequence s1)

Visit the specified sequence.

visit

public java.lang.Boolean visit(Binding b1)

Visit the specified binding.

visit

public java.lang.Boolean visit(StringMatch m1)

Visit the specified string match.

visit

public java.lang.Boolean visit(NonTerminal nt1)

Visit the specified nonterminal.

visit

public java.lang.Boolean visit(CharSwitch s1)

Visit the specified character switch.

visit

public java.lang.Boolean visit(ParseTreeNode n1)

Visit the specified parse tree node.

visit

public java.lang.Boolean visit(ProperListValue v1)

Visit the specified proper list value.

visit

public java.lang.Boolean visit(BindingValue v1)

Visit the specified binding value.

visit

public java.lang.Boolean visit(ActionBaseValue v1)

Visit the specified action base value.

visit

public java.lang.Boolean visit(GenericNodeValue v1)

Visit the specified generic node value.

visit

public java.lang.Boolean visit(GenericActionValue v1)

Visit the specified generic action value.

visit

public java.lang.Boolean visit(GenericRecursionValue v1)

Visit the specified generic recursion value.

visit

public java.lang.Boolean visit(UnaryOperator op1)

Visit the specified unary operator. This method provides the default implementation for options, predicates, voided elements, and parser actions.

visit

public java.lang.Boolean visit(Element e1)

Visit the specified element. This method provides the default implementation for terminals, node markers, null literals, actions, and null, string, text, empty list, generic string, and generic text values.