> On 20 Feb 2015, at 06:23, S Krish <krishnamachari.sudha...@gmail.com> wrote: > > > I presumed shallowCopy for literal arrays / OrderedCollection should have > been a true copy. Perhaps need to understand this.. >
OrderdCollection is not just one object, but it holds on to an Array that has it’s content. You copy the outside collection object, but share the Array. > shallowCopy > "Answer a copy of the receiver which shares the receiver's instance > variables. It should never be overridden. I'm invoked from the copy template > method. Subclasses that need to specialize the copy should specialize the > postCopy hook method." > ... > <primitive: 148> > class := self class. > class isVariable > ifTrue: > [... newObject := class basicNew: index. ....] > ifFalse: [newObject := class basicNew]. > .. > whileTrue: > [newObject instVarAt: index put: (self instVarAt: index). > ... > ^ newObject > > On Wed, Feb 18, 2015 at 10:52 PM, Marcus Denker <marcus.den...@inria.fr > <mailto:marcus.den...@inria.fr>> wrote: > >> On 18 Feb 2015, at 18:13, Cameron Sanders via Pharo-users >> <pharo-users@lists.pharo.org <mailto:pharo-users@lists.pharo.org>> wrote: >> >> >> Date: 18 Feb 2015 18:12:33 CET >> Subject: i feel dumb / Pharo3 > OrderedCollection >> do: >> From: Cameron Sanders <camsand...@aol.com <mailto:camsand...@aol.com>> >> To: Any question about pharo is welcome <pharo-users@lists.pharo.org >> <mailto:pharo-users@lists.pharo.org>> >> >> >> I must be making some silly error here that i cannot see clearly. Why does >> the following leave anything in the list 'a'? Run it in a workspace. With or >> without the shallowCopy, i am left with a list with half of the elements in >> it. Always half. >> >> This version of Pharo3 (21.0) was downloaded last week. I am running on a >> Mac. >> >> Thanks in advance. ... Maybe I just need more coffee. >> -Cam >> >> | a | >> a := { #a. #b. #c. #d. } asOrderedCollection. >> a shallowCopy do: [ :item | (a includes: item) ifTrue: [ a remove: item ]]. >> a size >> > > shallowCopy is not enough… OrderedCollection is made up of an internal array. > > #copy does the right thing, just copies the array: > > postCopy > array := array copy > > and for Array, copy is a shallowCopy. > > Marcus > > > >
