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

"{ NameSpace: SmaCC }"

Object subclass:#SmaCCRHS

	instanceVariableNames:'collection reduceAction variableNames'

	classVariableNames:''

	poolDictionaries:''

	category:'SmaCC-Parser Generator'

!

SmaCCRHS comment:'SmaCCRHS represents the right hand side of the production.

Instance variables:

	collection	<OrderedCollection of: SmaCCSymbol> the collection of symbols that represent the rhs

	grammar <SmaCCGrammar> the grammar that the production is in

	variableNames	<Dictionary key: String value: Integer>	the name of each symbol in the rhs. These names can be used in the {} code blocks.'

!

!SmaCCRHS class methodsFor:'instance creation'!

new

	^(super new)

		initialize;

		yourself

! !

!SmaCCRHS methodsFor:'accessing'!

add: aGrammarSymbol 

	collection add: aGrammarSymbol

!

at: anInteger 

	^collection at: anInteger

!

do: aBlock

	collection do: aBlock

!

firstTerminals

	| items |

	collection isEmpty ifTrue: [^Set with: SmaCCSymbol empty].

	items := Set new.

	1 to: collection size

		do: 

			[:index | 

			items addAll: (collection at: index) firstTerminals.

			(items includes: SmaCCSymbol empty) 

				ifTrue: [index < collection size ifTrue: [items remove: SmaCCSymbol empty]]

				ifFalse: [^items]].

	^items

!

nameLastItem: aString 

	variableNames at: aString put: collection size

!

reduceAction

	^reduceAction

!

reduceAction: anObject

	reduceAction := anObject

!

size

	^collection size

! !

!SmaCCRHS methodsFor:'comparing'!

= aRHS 

	^self class = aRHS class and: [collection = aRHS collection]

!

hash

	^self class hash bitXor: (collection hash bitShift: 14)

! !

!SmaCCRHS methodsFor:'initialize-release'!

initialize

	collection := OrderedCollection new.

	reduceAction := nil.

	variableNames := Dictionary new

! !

!SmaCCRHS methodsFor:'printing'!

printOn: aStream 

	^collection do: [:each | each printOn: aStream]

		separatedBy: [aStream space]

! !

!SmaCCRHS methodsFor:'private'!

collection

	^collection

!

defaultReduceAction

	^#reduceFor:

! !

!SmaCCRHS methodsFor:'public'!

compileSourceFor: aGrammarSymbol in: aClass

        | action rewriter parseTree methodName |

        action := self reduceAction.

        action isNil ifTrue: [^self defaultReduceAction].

        parseTree := RBParser parseExpression: action

                                onError: 

                                        [:s :p | 

                                        Smalltalk isSmalltalkX ifTrue:[

                                            SmaCCCompilationNotification raiseSignal: 'Invalid Smalltalk code in reduction rule'

                                                    with: aGrammarSymbol name , ' : ' , self printString , '\\' withCRs , action.

                                        ] ifFalse:[

                                            SmaCCCompilationNotification signal: 'Invalid Smalltalk code in reduction rule'

                                                    with: aGrammarSymbol name , ' : ' , self printString , '\\' withCRs , action.

                                        ].

                                        ^self defaultReduceAction].

        (parseTree isLiteral and: 

                        [parseTree value isSymbol 

                                and: [parseTree value argumentCount <= 1 and: [aClass definesMethod: parseTree value]]]) 

                ifTrue: [^parseTree value].

        rewriter := self parseTreeRewriter.

        rewriter executeTree: parseTree.

        parseTree := rewriter tree.

        methodName := ('reduceActionFor' , (self safeMethodNameFor: aGrammarSymbol) 

                                , (aGrammarSymbol positionOf: self) printString , ':') 

                                asSymbol.

        parseTree isSequence 

                ifFalse: [parseTree := RBSequenceNode statements: (Array with: parseTree)].

        parseTree := RBMethodNode 

                                selector: methodName

                                arguments: (Array with: (RBVariableNode named: 'nodes'))

                                body: parseTree.

        parseTree addReturn.

        aClass compile: parseTree formattedCode classified: 'generated-reduction actions'.

        ^methodName

!

parseTreeRewriter

	| rewriter |

	rewriter := ParseTreeRewriter new.

	1 to: self size

		do: 

			[:i | 

			rewriter replace: i printString storeString

				with: '(nodes at: ' , i printString , ')'].

	variableNames keysAndValuesDo: 

			[:key :value | 

			rewriter replace: key with: '(nodes at: ' , value printString , ')'].

	^rewriter

!

safeMethodNameFor: aGrammarSymbol 

	^aGrammarSymbol printString 

		collect: [:each | each isAlphaNumeric ifTrue: [each] ifFalse: [$_]]

! !

!SmaCCRHS class methodsFor:'documentation'!

version

    ^ '$Header: /opt/data/cvs/stx/goodies/smaCC/SmaCC__SmaCCRHS.st,v 1.1 2006-02-09 21:14:42 vranyj1 Exp $'

!

version_SVN

    ^ '$Id$'

! !