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The Trunk: Collections-eem.756.mcz

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Francisco Garau-2

Re: The Trunk: Collections-eem.756.mcz

How about #addWhenAbsent: ?

- Francisco

On 15 Jun 2017, at 23:58, Chris Muller <[hidden email]> wrote:

>> And, I didn't go with #ifMissingAdd: because it confuses the return value with the linguistic semantics -- e.g., if it returns true, does that mean it was "absent" or that it was added? forcing me to look at the method implementation again anyway.
>
> I think I confused this with a different one. ifMissingAdd:
> actually seems fine in terms of the return value semantics.. "true"
> would mean, "yes", it was missing and added.
>
> From there, saying we want to stay with the "Absent" terminology in the
> API seems reasonable.
>
> +1 for ifAbsentAdd:.
>

Stéphane Rollandin

Re: The Trunk: Collections-eem.756.mcz

In reply to this post by Eliot Miranda-2

>
> Stéphane, can you live with ifMissingAdd: ? Chris?
>

Sure. Now "missing" seems to imply that something went wrong and an
element is not there while it should (which is why I would prefer
#ifAbsentAdd:).

Plus, the name does not tell that a Boolean is returned (this apply to
#ifAbsentAdd: too).

So what about #ensurePresenceOf: ?

I would expect this to return true if the element was *not* added, false
otherwise, though.

Stef

Nicolai Hess-3-2

Re: The Trunk: Collections-eem.756.mcz

2017-06-16 12:38 GMT+02:00 Stéphane Rollandin <[hidden email]>:

Stéphane, can you live with ifMissingAdd: ? Chris?

Sure. Now "missing" seems to imply that something went wrong and an element is not there while it should (which is why I would prefer #ifAbsentAdd:).

Plus, the name does not tell that a Boolean is returned (this apply to #ifAbsentAdd: too).

So what about #ensurePresenceOf: ?

I would expect this to return true if the element was *not* added, false otherwise, though.

Stef

Does this even work ?

Set does not preserve ordering.

Item was added:
+ ----- Method: SequenceableCollection>>withoutDuplicates (in category 'copying') -----
+ withoutDuplicates
+ "Answer a copy of the receiver that preserves order but eliminates any duplicates."
+ | seen |
+ seen := Set new: self size.
+ ^self select: [:each|
+ (seen includes: each)
+ ifTrue: [false]
+ ifFalse: [seen add: each. true]]!

Levente Uzonyi

Re: The Trunk: Collections-eem.756.mcz

On Fri, 16 Jun 2017, Nicolai Hess wrote:

> Does this even work ?
> Set does not preserve ordering.

The receiver is not a Set but a SequenceableCollection, so yes, it does
work:

| set |
set := Set new.
#(1 1 2 1 2 3 1 2 3 4) select: [ :each | set addNewElement: each ]

"==> #(1 2 3 4)"

Levente

>
> Item was added:
> + ----- Method: SequenceableCollection>>withoutDuplicates (in category 'copying') -----
> + withoutDuplicates
> + "Answer a copy of the receiver that preserves order but eliminates any duplicates."
> + | seen |
> + seen := Set new: self size.
> + ^self select: [:each|
> + (seen includes: each)
> + ifTrue: [false]
> + ifFalse: [seen add: each. true]]!
>
>
>

Nicolai Hess-3-2

Re: The Trunk: Collections-eem.756.mcz

2017-06-16 14:16 GMT+02:00 Levente Uzonyi <[hidden email]>:

On Fri, 16 Jun 2017, Nicolai Hess wrote:

Does this even work ?
Set does not preserve ordering.

The receiver is not a Set but a SequenceableCollection, so yes, it does work:

| set |
set := Set new.
#(1 1 2 1 2 3 1 2 3 4) select: [ :each | set addNewElement: each ]

"==> #(1 2 3 4)"

Ah, of course :)

Set is only used for the select.

Levente

Item was added:
+ ----- Method: SequenceableCollection>>withoutDuplicates (in category 'copying') -----
+ withoutDuplicates
+ "Answer a copy of the receiver that preserves order but eliminates any duplicates."
+ | seen |
+ seen := Set new: self size.
+ ^self select: [:each|
+ (seen includes: each)
+ ifTrue: [false]
+ ifFalse: [seen add: each. true]]!