What about?

   20 timesCollect: [ 100 atRandom ] as: OrderedCollection

It could use cull: to accept the :index argument, or not.

It does seem that this (1 to: n) collect: [ :n| ...] has come up several
times over the years, but not always in the context of instantiating a
collection.

Let's take a side-by-side look:

OrderedCollection new: 20 filledWith: [100 atRandom].
>
>            20 timesCollect: [ 100 atRandom ] as: OrderedCollection

Hmm.  Although the number of words and elements seems about the same, the
order is different because the receiver is different.  Even though I like
the flexibility of #timesCollect:as: over #new:filledWith:, and also how it
echoes #collect:as:, object construction is typically the responsibility of
Classes, so, idiomatically, I think #new:filledWith: probably WOULD be
found afterall (even if not by me because of my habits).  I retract my -1.

I do still like #timesCollect: for those other cases though, since it saves
from needing to allocate the (1 to: n) Interval.  Hm.

Best,
  Chris


On Wed, Nov 20, 2019 at 1:48 AM Marcel Taeumel <marcel.taeumel at hpi.de>
wrote:

> Hi, all.
>
> What's the "most idiomatic" way to create an array with 100 random numbers
> > 0 < 100?
>
> (1 to: 100) collect: [:ea | 100 atRandom]
> Array streamContents: [:s | 100 timesRepeat: [s nextPut: 100 atRandom]].
> ...
>
> Best,
> Marcel
>
> Am 20.11.2019 07:08:34 schrieb Chris Muller <asqueaker at gmail.com>:
> On Tue, Nov 19, 2019 at 10:58 PM Chris Muller <asqueaker at gmail.com> wrote:
>
>> They share the same selector API, but for ArrayedCollection's, it culls
>> integers 1 to: n, while for non-Arrayed, it culls nil over and over.
>>
>
> Woops, I got that wrong, sorry.  It is the index in both cases, not nil.
> That's better but, still, I'm sure I would just write collect:as: without
> remembering this.
>
>  - Chris
>
>
>
>>   This means the sender will have to know whether it's Arrayed or not
>> anyway (otherwise you'd need a nil check inside the loop).  And so, if you
>> have to know that, one could just write classic Smalltalk.
>>
>>    (1 to: 20) collect: [ :i | ... ]
>>
>> (with or without an "as:" converter on the end).
>>
>> OTOH, if you were expecting a non-arrayed collection, then simply:
>>
>>     Array streamContents: [ : stream | ... ]
>>
>> I do appreciate the readability for people less experienced with
>> Smalltalk, but for the long run, classic, readable, portable Smalltalk may
>> actually be the better way for them to read it.
>>
>> Collecting nil over and over could be a sign of something not fully
>> optimized here.
>>
>> -1 on this one, even though I'm really enjoying many of your other
>> contributions, Christoph.
>>
>> Best,
>>   Chris
>>
>> On Fri, Sep 6, 2019 at 9:57 AM <commits at source.squeak.org> wrote:
>>
>>> A new version of Collections was added to project The Inbox:
>>> http://source.squeak.org/inbox/Collections-mt.852.mcz
>>>
>>> ==================== Summary ====================
>>>
>>> Name: Collections-mt.852
>>> Author: mt
>>> Time: 6 September 2019, 4:57:45.245608 pm
>>> UUID: 3582be1c-a006-ed46-a517-3d2d570db6cc
>>> Ancestors: Collections-mt.851
>>>
>>> Proposal: Initialize a new collection with a computation block without
>>> needing an existing collection to #collect: from.
>>>
>>> OrderedCollection new: 20 filledWith: [100 atRandom].
>>>
>>> Thanks to Christoph (ct) for the idea.
>>>
>>> If we want this in Trunk, there will be tests. :-)
>>>
>>> =============== Diff against Collections-mt.851 ===============
>>>
>>> Item was added:
>>> + ----- Method: ArrayedCollection class>>new:filledWith: (in category
>>> 'instance creation') -----
>>> + new: size filledWith: aBlock
>>> +       "Similar to #collect:as: and #fillFrom:with: but uses only the
>>> interval (1 to: size) to fill the collection. Different compared to
>>> #new:withAll: because aBlock can return different values for each index."
>>> +
>>> +       | result |
>>> +       result := self new: size.
>>> +       1 to: size do: [:each | result at: each put: (aBlock cull:
>>> each)].
>>> +       ^ result!
>>>
>>> Item was added:
>>> + ----- Method: Collection class>>new:filledWith: (in category 'instance
>>> creation') -----
>>> + new: size filledWith: aBlock
>>> +       "Similar to #collect:as: and #fillFrom:with: but uses only the
>>> interval (1 to: size) to fill the collection. Different compared to
>>> #new:withAll: because aBlock can return different values for each index."
>>> +
>>> +       | result |
>>> +       result := self new: size.
>>> +       1 to: size do: [:each | result add: (aBlock cull: each)].
>>> +       ^ result!
>>>
>>>
>>>
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