--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler/PEGFsaStateInfo.st	Mon Aug 17 12:13:16 2015 +0100
@@ -0,0 +1,212 @@
+"{ Package: 'stx:goodies/petitparser/compiler' }"
+
+"{ NameSpace: Smalltalk }"
+
+Object subclass:#PEGFsaStateInfo
+	instanceVariableNames:'priority final failure'
+	classVariableNames:''
+	poolDictionaries:''
+	category:'PetitCompiler-FSA'
+!
+
+!PEGFsaStateInfo methodsFor:'accessing'!
+
+failure
+    ^ failure
+!
+
+failure: anObject
+    failure := anObject
+!
+
+final
+    ^ final
+!
+
+final: anObject
+    final := anObject
+!
+
+priority
+    ^ priority
+!
+
+priority: anObject
+    priority := anObject
+! !
+
+!PEGFsaStateInfo methodsFor:'comparing'!
+
+= anotherInfo
+    (self == anotherInfo) ifTrue: [ ^ true ].
+    (self class == anotherInfo class) ifFalse: [ ^ false ].
+    
+    (priority == anotherInfo priority) ifFalse: [ ^ false ].
+
+    (self isFinal == anotherInfo isFinal) ifFalse: [ ^ false ].
+
+    ^ true
+!
+
+equals: anotherInfo
+    self error: 'deprecated'.
+    (self == anotherInfo) ifTrue: [ ^ true ].
+    (self class == anotherInfo class) ifFalse: [ ^ false ].
+
+    "	
+        I suppose I don't if someone does not have the priority set.
+        Please note that equals is used for minimization, so I try to
+        be as liberal as possible to get as small automaton as possible.
+    "
+    (self hasPriority and: [anotherInfo hasPriority]) ifTrue: [ 	
+        (priority == anotherInfo priority) ifFalse: [ ^ false ].
+    ].
+
+    (self isFinal == anotherInfo isFinal) ifFalse: [ ^ false ].
+
+    ^ true
+! !
+
+!PEGFsaStateInfo methodsFor:'modifications - determinization'!
+
+join: info into: newInfo
+    self error: 'deprecated'.
+    "
+        The diff between JOIN and Merge:
+        - join is used while determinizing the FSA
+        - merge is used when removing epsilons
+    "
+
+    (self hasEqualPriorityTo: info) ifTrue: [ 
+        newInfo final: (self isFinal or: [ info isFinal ]).
+ 		newInfo priority: self priority.	
+        ^ self
+    ].
+    
+    (self hasHigherPriorityThan: info) ifTrue: [ 
+ 		newInfo priority: self priority.	
+        newInfo final: self isFinal.
+        ^ self
+    ].
+
+    newInfo priority: info priority.
+    newInfo final: info isFinal.
+! !
+
+!PEGFsaStateInfo methodsFor:'printing'!
+
+printOn: aStream
+    priority isNil ifFalse: [ 
+        priority printOn: aStream.
+        aStream nextPutAll: ', '	
+    ].
+
+    self isFinal ifTrue: [ 
+        aStream nextPutAll: 'FINAL'.
+        aStream nextPutAll: ', '	
+    ].
+
+    self isFsaFailure ifTrue: [ 
+        aStream nextPutAll: 'FAILURE'
+    ].
+! !
+
+!PEGFsaStateInfo methodsFor:'testing'!
+
+hasEqualPriorityTo: stateInfo
+    "nil - nil"
+    (self hasPriority not and: [stateInfo hasPriority not]) ifTrue: [ ^ true ].
+    
+    "nil - priority"
+    (self hasPriority) ifFalse: [ ^ false ].
+    
+    "priority - nil"
+    stateInfo hasPriority ifFalse: [ ^ false ].
+    
+    "priority - priority"
+    ^ self priority = stateInfo priority 
+!
+
+hasHigherPriorityThan: stateInfo
+    "nil - nil"
+    (self hasPriority not and: [stateInfo hasPriority not]) ifTrue: [ ^ true ].
+    
+    "nil - priority"
+    (self hasPriority) ifFalse: [ ^ false ].
+    
+    "priority - nil"
+    stateInfo hasPriority ifFalse: [ ^ true ].
+    
+    "priority - priority"
+    ^ self priority > stateInfo priority 
+!
+
+hasPriority
+    ^ self priority isNil not
+!
+
+isBlank
+    ^ self hasPriority not and: [ self isFinal not ]
+!
+
+isFinal
+    final isNil ifTrue: [ ^ false ].
+    ^ final
+!
+
+isFsaFailure
+    failure isNil ifTrue: [ ^ false ].
+    ^ failure
+! !
+
+!PEGFsaStateInfo methodsFor:'transformation'!
+
+merge: info into: newInfo
+    "
+        The diff between JOIN and Merge:
+        - join is used while determinizing the FSA
+        - merge is used when removing epsilons
+    "
+
+    "final - final"
+    (self isFinal and: [info isFinal]) ifTrue: [ 
+        newInfo final: true.
+        (self hasHigherPriorityThan: info) ifTrue: [  
+            newInfo priority: self priority.
+        ] ifFalse: [  
+            newInfo priority: info priority.
+        ].
+        "
+            This has its reason: when moving from failure to non-failure
+            using the epsilon, just keep the latter:
+        "
+        newInfo failure: info isFsaFailure.
+        ^ self
+ 	].
+
+    "final - non final"
+    (self isFinal) ifTrue: [ 
+        newInfo final: true.
+        newInfo priority: self priority.
+        newInfo failure: self isFsaFailure.
+        ^ self
+    ].
+
+    "non final - final"
+    (info isFinal) ifTrue: [ 
+        newInfo final: true.
+        newInfo priority: info priority.
+        newInfo failure: info isFsaFailure.
+        ^ self
+    ].
+    
+    "non final - non final"
+ 	newInfo priority: self priority.	
+    (self hasHigherPriorityThan: info) ifTrue: [  
+        newInfo priority: self priority.
+    ] ifFalse: [  
+        newInfo priority: info priority.
+    ].
+    newInfo failure: info isFsaFailure.
+! !
+