antlr/Antlr4.Runtime/Atn/PredicateTransition.cs

97 lines
3.4 KiB
C#

/*
* [The "BSD license"]
* Copyright (c) 2013 Terence Parr
* Copyright (c) 2013 Sam Harwell
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
using Antlr4.Runtime.Atn;
using Antlr4.Runtime.Misc;
using Sharpen;
namespace Antlr4.Runtime.Atn
{
/// <summary>
/// TODO: this is old comment:
/// A tree of semantic predicates from the grammar AST if label==SEMPRED.
/// </summary>
/// <remarks>
/// TODO: this is old comment:
/// A tree of semantic predicates from the grammar AST if label==SEMPRED.
/// In the ATN, labels will always be exactly one predicate, but the DFA
/// may have to combine a bunch of them as it collects predicates from
/// multiple ATN configurations into a single DFA state.
/// </remarks>
public sealed class PredicateTransition : AbstractPredicateTransition
{
public readonly int ruleIndex;
public readonly int predIndex;
public readonly bool isCtxDependent;
public PredicateTransition(ATNState target, int ruleIndex, int predIndex, bool isCtxDependent
) : base(target)
{
// e.g., $i ref in pred
this.ruleIndex = ruleIndex;
this.predIndex = predIndex;
this.isCtxDependent = isCtxDependent;
}
public override Antlr4.Runtime.Atn.TransitionType TransitionType
{
get
{
return Antlr4.Runtime.Atn.TransitionType.Predicate;
}
}
public override bool IsEpsilon
{
get
{
return true;
}
}
public override bool Matches(int symbol, int minVocabSymbol, int maxVocabSymbol)
{
return false;
}
public SemanticContext.Predicate GetPredicate()
{
return new SemanticContext.Predicate(ruleIndex, predIndex, isCtxDependent);
}
[return: NotNull]
public override string ToString()
{
return "pred_" + ruleIndex + ":" + predIndex;
}
}
}