Portability fixes
* do not use Object>>asString. Not all Smalltalks implement it.
* do not use Object>>name. Not all Smalltalks implement it.
* do not use Dictionary keysAndValuesRemove:. Not all Smalltalks implement it.
* do not use Class>>methods The semantics is different among Smalltalks.
Use `Class methodDictionary values` instead.
* do not modify dictionary in #at:ifAbsentPut: block!
"{ Package: 'stx:goodies/petitparser/compiler' }"
"{ NameSpace: Smalltalk }"
PPCRewritingVisitor subclass:#PPCMergingVisitor
instanceVariableNames:'nodeSet'
classVariableNames:''
poolDictionaries:''
category:'PetitCompiler-Visitors'
!
!PPCMergingVisitor methodsFor:'as yet unclassified'!
equivalentNode: node
^ nodeSet detect: [ :e | e = node ]
!
hasEquivalentNode: node
^ nodeSet includes: node
!
initialize
super initialize.
nodeSet := Set new
!
store: node
self assert: (self hasEquivalentNode: node) not.
nodeSet add: node
!
visitNode: node
super visitNode: node.
(self hasEquivalentNode: node) ifTrue: [
self change.
^ self equivalentNode: node
] ifFalse: [
self store: node
].
^ node
! !