Package org.antlr.analysis

Class PredicateLabel

  • All Implemented Interfaces:
    java.lang.Cloneable, java.lang.Comparable<Label>
    public class PredicateLabel
extends Label

    • 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​(java.lang.Object o)
        Overrides:
        equals in class Label

      • toString

        public java.lang.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