"{ 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.

! !