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

Object subclass:#PPCContextMemento

	instanceVariableNames:'position properties'

	classVariableNames:''

	poolDictionaries:''

	category:'PetitCompiler-Context'

!

PPCContextMemento comment:''

!

!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

                ifTrue: [ ^ aBlock value ]

                ifFalse: [ 

                        (properties includesKey: aKey) ifTrue: [ 

                                ^ (properties at: aKey) copy

                        ].

                        ^ aBlock value

                ]

    "Created: / 26-10-2014 / 01:23:09 / 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.

    "Modified: / 26-10-2014 / 01:46:37 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !