PPMemoizedParser.st
author Jan Vrany <jan.vrany@fit.cvut.cz>
Thu, 30 Jul 2015 08:37:37 +0100
changeset 510 869853decf31
parent 377 6112a403a52d
child 642 77d5fddb6462
permissions -rw-r--r--
Tests refactoring - use generated test cases to make sure all posibilities are tested. Do not generate resource for all combinations, use PPCSetUpBeforeTearDownAfterResource instead that delegates parser compilation to the testcase itself (it calls it's #setUpBefore method).

"{ Package: 'stx:goodies/petitparser' }"

PPDelegateParser subclass:#PPMemoizedParser
	instanceVariableNames:'buffer context hash'
	classVariableNames:''
	poolDictionaries:''
	category:'PetitParser-Parsers'
!


!PPMemoizedParser methodsFor:'operations'!

memoized
	"Ther is no point in memoizing more than once."

	^ self
! !

!PPMemoizedParser methodsFor:'parsing'!

parseOn: aPPContext
	| memento contextMemento  aStream |
	"TODO: JK memoizing needs review!!"
	
	contextMemento := aPPContext remember.
	(hash == aPPContext hash)
		ifFalse: [ self reset: aPPContext ].
	memento := (buffer at: contextMemento ifAbsentPut: [ PPMemento new ]).
	
	memento contextMemento isNil
		ifTrue: [
			aStream := aPPContext stream.
			memento result: (aStream size - aStream position + 2 < memento count
				ifTrue: [ PPFailure message: 'overflow' context: aPPContext ]
				ifFalse: [ memento increment. parser parseOn: aPPContext ]).
			memento contextMemento: aPPContext remember ]
		ifFalse: [ context restore: memento contextMemento ].
	^ memento result.
!

reset: aPPContext
	hash := aPPContext hash.
	context := aPPContext.
	buffer := Dictionary new.
! !

!PPMemoizedParser class methodsFor:'documentation'!

version
    ^ '$Header: /cvs/stx/stx/goodies/petitparser/PPMemoizedParser.st,v 1.3 2012-05-04 21:58:48 vrany Exp $'
!

version_CVS
    ^ '$Header: /cvs/stx/stx/goodies/petitparser/PPMemoizedParser.st,v 1.3 2012-05-04 21:58:48 vrany Exp $'
!

version_SVN
    ^ '§Id: PPMemoizedParser.st 2 2010-12-17 18:44:23Z vranyj1 §'
! !