org.antlr.analysis

Class SemanticContext.Predicate

java.lang.Object

org.antlr.analysis.SemanticContext

org.antlr.analysis.SemanticContext.Predicate

Direct Known Subclasses:

SemanticContext.TruePredicate

Enclosing class:

SemanticContext

public static class SemanticContext.Predicate
extends SemanticContext

Nested Class Summary

Nested classes/interfaces inherited from class org.antlr.analysis.SemanticContext

SemanticContext.AND, SemanticContext.NOT, SemanticContext.OR, SemanticContext.Predicate, SemanticContext.TruePredicate

Field Summary

Fields

Modifier and Type	Field and Description
protected int	constantValue sometimes predicates are known to be true or false; we need a way to represent this without resorting to a target language value like true or TRUE.
static int	FALSE_PRED
protected boolean	gated Is this a {...}?=> gating predicate or a normal disambiguating {..}? If any predicate in expression is gated, then expression is considered gated.
static int	INVALID_PRED_VALUE
GrammarAST	predicateAST The AST node in tree created from the grammar holding the predicate
protected boolean	synpred syntactic predicates are converted to semantic predicates but synpreds are generated slightly differently.
static int	TRUE_PRED

Fields inherited from class org.antlr.analysis.SemanticContext

EMPTY_SEMANTIC_CONTEXT

Constructor Summary

Constructors

Constructor and Description
SemanticContext.Predicate()
SemanticContext.Predicate(GrammarAST predicate)
SemanticContext.Predicate(SemanticContext.Predicate p)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object o) Two predicates are the same if they are literally the same text rather than same node in the grammar's AST.
org.antlr.stringtemplate.StringTemplate	genExpr(CodeGenerator generator, org.antlr.stringtemplate.StringTemplateGroup templates, DFA dfa) Generate an expression that will evaluate the semantic context, given a set of output templates.
SemanticContext	getGatedPredicateContext() Given a semantic context expression tree, return a tree with all nongated predicates set to true and then reduced.
int	hashCode()
boolean	isSyntacticPredicate()
String	toString()
void	trackUseOfSyntacticPredicates(Grammar g) Notify the indicated grammar of any syn preds used within this context

Methods inherited from class org.antlr.analysis.SemanticContext

and, not, or

Methods inherited from class java.lang.Object

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

Field Detail

predicateAST

public GrammarAST predicateAST

The AST node in tree created from the grammar holding the predicate

gated

protected boolean gated

Is this a {...}?=> gating predicate or a normal disambiguating {..}? If any predicate in expression is gated, then expression is considered gated. The simple Predicate object's predicate AST's type is used to set gated to true if type==GATED_SEMPRED.

synpred

protected boolean synpred

syntactic predicates are converted to semantic predicates but synpreds are generated slightly differently.

INVALID_PRED_VALUE

public static final int INVALID_PRED_VALUE

See Also:

Constant Field Values

FALSE_PRED

public static final int FALSE_PRED

See Also:

Constant Field Values

TRUE_PRED

public static final int TRUE_PRED

See Also:

Constant Field Values

constantValue

protected int constantValue

sometimes predicates are known to be true or false; we need a way to represent this without resorting to a target language value like true or TRUE.

Constructor Detail

SemanticContext.Predicate

public SemanticContext.Predicate()

SemanticContext.Predicate

public SemanticContext.Predicate(GrammarAST predicate)

SemanticContext.Predicate

public SemanticContext.Predicate(SemanticContext.Predicate p)

Method Detail

equals

public boolean equals(Object o)

Two predicates are the same if they are literally the same text rather than same node in the grammar's AST. Or, if they have the same constant value, return equal. As of July 2006 I'm not sure these are needed.

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

genExpr

public org.antlr.stringtemplate.StringTemplate genExpr(CodeGenerator generator,
                                              org.antlr.stringtemplate.StringTemplateGroup templates,
                                              DFA dfa)

Description copied from class: SemanticContext

Generate an expression that will evaluate the semantic context, given a set of output templates.

Specified by:

genExpr in class SemanticContext

getGatedPredicateContext

public SemanticContext getGatedPredicateContext()

Description copied from class: SemanticContext

Given a semantic context expression tree, return a tree with all nongated predicates set to true and then reduced. So p&&(q||r) would return p&&r if q is nongated but p and r are gated.

Specified by:

getGatedPredicateContext in class SemanticContext

isSyntacticPredicate

public boolean isSyntacticPredicate()

Specified by:

isSyntacticPredicate in class SemanticContext

trackUseOfSyntacticPredicates

public void trackUseOfSyntacticPredicates(Grammar g)

Description copied from class: SemanticContext

Notify the indicated grammar of any syn preds used within this context

Overrides:

trackUseOfSyntacticPredicates in class SemanticContext

toString

public String toString()

Overrides:

toString in class Object