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

"{ NameSpace: Smalltalk }"

Object subclass:#PPCContextMemento
	instanceVariableNames:'position properties'
	classVariableNames:''
	poolDictionaries:''
	category:'PetitCompiler-Context'
!

!PPCContextMemento methodsFor:'accessing'!

position
    ^ position
!

position: anInteger
    position := anInteger 
! !

!PPCContextMemento methodsFor:'accessing - properties'!

hasProperty: aKey
    "Test if the property aKey is present."
    
    ^ properties notNil and: [ properties includesKey: aKey ]
!

keysAndValuesDo: aBlock
    properties ifNil: [ ^ self ].
    properties keysAndValuesDo: [ :key :value | aBlock value: key value: value copy ] 
!

propertiesSize
    properties ifNil: [ ^ 0 ].
    ^ properties size.
!

propertyAt: aKey
    "Answer the property value associated with aKey."
    
    ^ self propertyAt: aKey ifAbsent: [ self error: 'Property not found' ]
!

propertyAt: aKey ifAbsent: aBlock
    "Answer the property value associated with aKey or, if aKey isn't found, answer the result of evaluating aBlock."
        
    properties isNil ifFalse: [ 
        (properties includesKey: aKey) ifTrue: [ 
            ^ (properties at: aKey) copy
        ].
    ].
    ^ aBlock value

    "Modified: / 15-04-2015 / 11:19:20 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

propertyAt: aKey ifAbsentPut: aBlock
    "Answer the property associated with aKey or, if aKey isn't found store the result of evaluating aBlock as new value."
    
    ^ self propertyAt: aKey ifAbsent: [ self propertyAt: aKey put: aBlock value ]
!

propertyAt: aKey put: anObject
    "Set the property at aKey to be anObject. If aKey is not found, create a new entry for aKey and set is value to anObject. Answer anObject."

    ^ (properties ifNil: [ properties := Dictionary new: 1 ])
        at: aKey put: (anObject copy)
!

removeProperty: aKey
    "Remove the property with aKey. Answer the property or raise an error if aKey isn't found."
    
    ^ self removeProperty: aKey ifAbsent: [ self error: 'Property not found' ]
!

removeProperty: aKey ifAbsent: aBlock
    "Remove the property with aKey. Answer the value or, if aKey isn't found, answer the result of evaluating aBlock."
    
    | answer |
    properties isNil ifTrue: [ ^ aBlock value ].
    answer := properties removeKey: aKey ifAbsent: aBlock.
    properties isEmpty ifTrue: [ properties := nil ].
    ^ answer
! !

!PPCContextMemento methodsFor:'comparing'!

= anObject
    
    (self == anObject) ifTrue: [ ^ true ].
    (anObject class = PPCContextMemento) ifFalse: [ ^ false ].
    
    (anObject position = position) ifFalse: [ ^ false ].

    (self propertiesSize = anObject propertiesSize) ifFalse: [ ^ false ].

    self keysAndValuesDo: [ :key :value |
        (anObject hasProperty: key) ifFalse: [ ^ false ].
        ((anObject propertyAt: key) = value) ifFalse: [ ^ false ]. 
 	].
    
    ^ true.
!

hash
    ^ position hash bitXor: properties hash.
! !