Loyc.LLParserGenerator.LLParserGenerator.GetCanonical Class Reference

Computes the "canonical" interpretation of a position for prediction purposes, so that ConsolidateDuplicatePositions can detect duplicates reliably. Call Do() to use. More...

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Source file:

• /Main/LLLPG/CoreEngine/LLParserGenerator.cs

Inheritance diagram for Loyc.LLParserGenerator.LLParserGenerator.GetCanonical:

Remarks

Computes the "canonical" interpretation of a position for prediction purposes, so that ConsolidateDuplicatePositions can detect duplicates reliably. Call Do() to use.

Public Member Functions
GrammarPos	Do (GrammarPos input)
	Computes the "canonical" interpretation of a position. More...
override void	Visit (Seq seq)
override void	Visit (Gate gate)
override void	Visit (EndOfRule end)
override void	VisitOther (Pred pred)
Public Member Functions inherited from Loyc.LLParserGenerator.PredVisitor
void	Visit (Pred pred)
virtual void	Visit (TerminalPred term)
virtual void	Visit (RuleRef rref)
virtual void	Visit (Alts alts)
virtual void	Visit (AndPred and)
void	VisitChildrenOf (Seq pred)
void	VisitChildrenOf (AndPred pred)
void	VisitChildrenOf (Gate pred)
void	VisitChildrenOf (Alts pred, bool includeError)

Member Function Documentation

GrammarPos Loyc.LLParserGenerator.LLParserGenerator.GetCanonical.Do ( GrammarPos  input )

inline

Computes the "canonical" interpretation of a position.

For example, given

rule X @[ 'a' Y 'z' ];
rule Y @[ 'a'..'y' 'b'..'z' ];

The position before the sequence 'a' Y 'z' is equivalent to the position before 'a', so the result points to 'a' rather than to the sequence itself.

The position after 'b'..'z' is equivalent to the position before 'z', if Y was called from X. Therefore, given the position after 'b'..'z' (a pointer to EndOfRule), and return address before 'z', this method returns the position before 'z'.