Hi Nicolas,
in any case the comment needs to specify that behavior, e.g.
Collection>>ifNotEmpty: aBlock
"Evaluate the given block with the receiver as argument, answering its
value
unless the receiver is empty, in which case answer the receiver."
^self isEmpty
ifTrue: [self]
ifFalse: [aBlock valueWithPossibleArgument: self]
and in this case IMO the explicit return self is better than the implicit
one.
On Fri, Jul 2, 2010 at 2:34 PM, Nicolas Cellier <
[email protected]> wrote:
> 2010/7/2 Simon Denier <[email protected]>:
> > I just noticed that the semantic of Collection>>ifNotEmpty: has changed
> in subtle ways between Pharo 1.0 and 1.1
> >
> > In 1.0
> > Collection>>ifNotEmpty: aBlock
> > "Evaluate the given block unless the receiver is empty.
> >
> > If the block has an argument, eval with the receiver as its argument,
> > but it might be better to use ifNotEmptyDo: to make the code easier
> to
> > understand"
> >
> > ^self isEmpty ifFalse: [aBlock valueWithPossibleArgument: self].
> >
> > -----> it returns nil if collection is empty
> >
> >
> > in 1.1
> > Collection>>ifNotEmpty: aBlock
> > "Evaluate the given block unless the receiver is empty.
> >
> > If the block has an argument, eval with the receiver as its argument,
> > but it might be better to use ifNotEmptyDo: to make the code easier
> to
> > understand"
> >
> > self isEmpty ifFalse: [^ aBlock valueWithPossibleArgument: self].
> >
> > ----> the return is inside the block, now it returns the collection if
> collection is empty
> >
> >
> > Apparently all similar code (#ifEmpty:....) has been adapted in the same
> way.
> >
> > Of course I would not have stumbled upon this change if it didn't break
> some of my code which rely on the previous assumption.
> >
> > Now I would like to understand before making some change in my code. Is
> it considered bad practice to return nil in such cases? What is the
> rationale to return yourself instead of nil?
> >
>
> The new version is better because:
> - it is homogeneous with ifNil: behaviour
> - it enables writing: self classifyMethodAs: (myProtocol ifEmpty:
> ['As yet unclassified'])
>
> Nicolas
>
> > --
> > Simon
> >
> >
> >
> > _______________________________________________
> > Pharo-project mailing list
> > [email protected]
> > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
> >
>
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