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

"{ NameSpace: Smalltalk }"

PPCListNode subclass:#PPCChoiceNode
	instanceVariableNames:''
	classVariableNames:''
	poolDictionaries:''
	category:'PetitCompiler-Nodes'
!

!PPCChoiceNode methodsFor:'as yet unclassified'!

acceptsEpsilon
	^ self acceptsEpsilonOpenSet: IdentitySet new.
!

acceptsEpsilonOpenSet: set
	set add: self.
	^ self children anySatisfy: [:e | e acceptsEpsilonOpenSet: set ].
!

compileWith: compiler effect: effect id: id
	| firsts guard whitespaceConsumed |

	whitespaceConsumed := false.
	firsts := (self firstSetSuchThat: [ :e | (e isKindOf: PPCTrimmingTokenNode) or: [ e isTerminal ] ]).
	
	compiler startMethod: id.
	compiler addVariable: 'element'.

	"If we start with trimming token, we should invoke the whitespace parser"
	(firsts allSatisfy: [ :e | e isKindOf: PPCTrimmingTokenNode ]) ifTrue: [  
		firsts anyOne compileWhitespace: compiler.
		whitespaceConsumed := true.
	].
	
	(1 to: children size) do: [ :idx  | |child allowGuard |
		child := children at: idx.
"		allowGuard := ((child isKindOf: PPCTrimmingTokenNode) and: [ whitespaceConsumed not ]) not.
"	
		allowGuard := whitespaceConsumed.
				
 		(allowGuard and: [compiler guards and: [ (guard := PPCGuard on: child) makesSense ]]) ifTrue: [ 	
			guard id: (compiler idFor: guard prefixed: #guard).
			guard compileGuard: compiler.
			compiler add: ' ifTrue: [ '.
			compiler indent.
				compiler add: 'self clearError.'.
				compiler add: 'element := '.
				compiler callOnLine: (child compileWith: compiler).
				compiler add: 'error ifFalse: [ ^ element ].'.
			compiler dedent.
			compiler add: ' ].'.
		] ifFalse: [
			compiler add: 'self clearError.'.
			compiler add: 'element := '.
			compiler callOnLine: (child compileWith: compiler).
			compiler add: 'error ifFalse: [ ^ element ].'.
		]
	].
	compiler add: '^ self error: ''no choice suitable'''.
 ^ compiler stopMethod.
!

prefix
	^ #ch
! !