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

"{ NameSpace: SmaCC }"

Object subclass:#SmaCCRegularExpressionNode

	instanceVariableNames:'action position'

	classVariableNames:''

	poolDictionaries:''

	category:'SmaCC-Scanner Generator'

!

SmaCCRegularExpressionNode comment:'SmaCCRegularExpressionNode represents a regular expression. The scanner is represented by a regular expression. These are the initial objects created in producing the scanner. From these nodes, we create a directed graph and then we compile the graph.

Subclasses must implement the following messages:

	accessing

		possibleMatchesSize

	private

		asNFAStartingWith:

		possibleMatchesDo:on:

Instance Variables:

	action	<SequenceableCollection>	the actions to be performed when we find a match

	position	<Integer>	the position of the RE in the scanner. If we have multiple matches, we prefer the ones listed first.'

!

!SmaCCRegularExpressionNode class methodsFor:'instance creation'!

new

	^(super new)

		initialize;

		yourself

! !

!SmaCCRegularExpressionNode methodsFor:'accessing'!

, aScannerNode 

	^SmaCCSequenceRENode nodes: (OrderedCollection with: self with: aScannerNode)

!

position

	^position

!

position: anInteger

	position := anInteger

!

possibleMatches

	| matches |

	matches := OrderedCollection new.

	self possibleMatchesDo: [:each | matches add: each].

	^matches

!

possibleMatchesDo: aBlock 

	| stream |

	stream := WriteStream on: String new.

	self possibleMatchesDo: [aBlock value: stream contents] on: stream

!

possibleMatchesSize

	^self subclassResponsibility

!

repeat

	^SmaCCRepeatingRENode component: self

!

repeatFor: minimum to: maximum 

	^SmaCCRepeatingRENode 

		component: self

		minimum: minimum

		maximum: maximum

!

repeatForAtLeast: minimum 

	^SmaCCRepeatingRENode component: self minimum: minimum

!

| aScannerNode 

	^SmaCCOrRENode nodes: (OrderedCollection with: self with: aScannerNode)

! !

!SmaCCRegularExpressionNode methodsFor:'converting'!

asDFA

	| startNode |

	startNode := SmaCCNode new.

	self asNFAStartingWith: startNode.

	^startNode asNFAWithoutEpsilonTransitions asDFA

! !

!SmaCCRegularExpressionNode methodsFor:'initialize-release'!

action

	^action

!

action: aString

	action := aString

!

initialize

! !

!SmaCCRegularExpressionNode methodsFor:'private'!

asNFAStartingWith: startNode 

	^self subclassResponsibility

!

possibleMatchesDo: aBlock on: aStream 

	self subclassResponsibility

! !

!SmaCCRegularExpressionNode methodsFor:'public'!

isKeywordLiteral

	self possibleMatchesSize < 50 ifFalse: [^false].

	self possibleMatchesDo: 

			[:each | 

			(each allSatisfy: [:char | char isAlphaNumeric or: [char == $_]]) 

				ifFalse: [^false]].

	^true

! !

!SmaCCRegularExpressionNode class methodsFor:'documentation'!

version

    ^ '$Header: /opt/data/cvs/stx/goodies/smaCC/SmaCC__SmaCCRegularExpressionNode.st,v 1.1 2006-02-09 21:15:38 vranyj1 Exp $'

!

version_SVN

    ^ '$Id$'

! !