🚀 go-pugleaf

In article <930106230330_73300.2046_EHJ21-1@CompuServe.COM> 73300.2046@compuserve.COM (Jim Pannozzi 73300.2046@compuserve.com) writes:
#		"Error: the method is the responsibility of the subclass".
#
#Date 1-6-93.
#
#Smaltalk Version 1.1.1
#
#Bug: Fails to do a ^data remove: super next 

The bug is that OrderedCollection does not define a method for
#remove:ifAbsent:

The Blue Book does state that OrderedCollection should support #remove:, and
in GNU Smalltalk, this is defined in Collection as:

remove: oldObject
    self remove: oldObject
         ifAbsent: [ ^self error: 'Failed to remove object' ].
    ^oldObject

This is still missing in version 1.2 (at least my version).  To make the
example from Chapter 11 work, try adding something like:

!OrderedCollection methodsFor: 'removing'!

remove: anElement ifAbsent: errorBlock
    | newCollection notFound |
    (self includes: anElement)
        ifFalse: errorBlock.
    newCollection := OrderedCollection new: self basicSize.
    notFound := true.
    self do: [ :elem | (notFound and: [elem = anElement])
                          ifFalse: [ newCollection add: elem ]
                          ifTrue: [ notFound := false ] ].
    self become: newCollection.
    ^anElement
!!

This works, but is probably not the best way of implementing this.

Mark