Do not use RBProgramNode>>variableNodesDo: as this method is not present in Pharo.
Use local helper method instead.
"{ Package: 'stx:goodies/petitparser/compiler' }"
"{ NameSpace: Smalltalk }"
PPCAbstractPredicateNode subclass:#PPCCharSetPredicateNode
instanceVariableNames:''
classVariableNames:''
poolDictionaries:''
category:'PetitCompiler-Nodes'
!
!PPCCharSetPredicateNode methodsFor:'as yet unclassified'!
start: compiler id: id
compiler startMethod: id
!
stop: compiler
^ compiler stopMethod
! !
!PPCCharSetPredicateNode methodsFor:'visiting'!
accept: visitor
^ visitor visitCharSetPredicateNode: self
! !