org.antlr.analysis

Class PredicateLabel

java.lang.Object

org.antlr.analysis.Label

org.antlr.analysis.PredicateLabel

All Implemented Interfaces:

Cloneable, Comparable

public class PredicateLabel
extends Label

Field Summary

Fields

Modifier and Type	Field and Description
protected SemanticContext	semanticContext A tree of semantic predicates from the grammar AST if label==SEMPRED.

Fields inherited from class org.antlr.analysis.Label

ACTION, DOWN, EOF, EOR_TOKEN_TYPE, EOT, EPSILON, EPSILON_STR, INVALID, label, labelSet, MAX_CHAR_VALUE, MIN_ATOM_VALUE, MIN_CHAR_VALUE, MIN_TOKEN_TYPE, NUM_FAUX_LABELS, SEMPRED, SET, UP

Constructor Summary

Constructors

Constructor and Description
PredicateLabel(GrammarAST predicateASTNode) Make a semantic predicate label
PredicateLabel(SemanticContext semCtx) Make a semantic predicates label

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object o)
SemanticContext	getSemanticContext()
int	hashCode()
boolean	isSemanticPredicate()
String	toString() Predicates are lists of AST nodes from the NFA created from the grammar, but the same predicate could be cut/paste into multiple places in the grammar.
String	toString(Grammar g)

Methods inherited from class org.antlr.analysis.Label

add, clone, compareTo, getAtom, getSet, intersect, isAction, isAtom, isEpsilon, isSet, matches, matches, matches, setSet

Methods inherited from class java.lang.Object

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

Field Detail

semanticContext

protected SemanticContext semanticContext

A tree of semantic predicates from the grammar AST if label==SEMPRED. In the NFA, labels will always be exactly one predicate, but the DFA may have to combine a bunch of them as it collects predicates from multiple NFA configurations into a single DFA state.

Constructor Detail

PredicateLabel

public PredicateLabel(GrammarAST predicateASTNode)

Make a semantic predicate label

PredicateLabel

public PredicateLabel(SemanticContext semCtx)

Make a semantic predicates label

Method Detail

hashCode

public int hashCode()

Overrides:

hashCode in class Label

equals

public boolean equals(Object o)

Overrides:

equals in class Label

isSemanticPredicate

public boolean isSemanticPredicate()

Overrides:

isSemanticPredicate in class Label

getSemanticContext

public SemanticContext getSemanticContext()

Overrides:

getSemanticContext in class Label

toString

public String toString()

Description copied from class: Label

Predicates are lists of AST nodes from the NFA created from the grammar, but the same predicate could be cut/paste into multiple places in the grammar. I must compare the text of all the predicates to truly answer whether {p1,p2} .equals {p1,p2}. Unfortunately, I cannot rely on the AST.equals() to work properly so I must do a brute force O(n^2) nested traversal of the Set doing a String compare. At this point, Labels are not compared for equals when they are predicates, but here's the code for future use.

Overrides:

toString in class Label

toString

public String toString(Grammar g)

Overrides:

toString in class Label