Le lun. 30 mars 2020 à 23:04, Levente Uzonyi <leves at caesar.elte.hu> a
écrit :

> Hi Christoph,
>
> On Mon, 30 Mar 2020, Thiede, Christoph wrote:
>
> >
> > Hi Nicolas,
> >
> >
> > I don't see your point of #doWhileTrue: being not idiomatic. What
> exactly do you mean by that except for "unfamiliar"?
> >
>

idiomatic: using, containing, or denoting expressions that are natural to a
native speaker.
So whileTrue: is natural for a native Smalltalker
(I don't know a lot of natives, it's not my first programming language
neither, but you get it).

#whileTrue should not be considered independently of the more powerful
#whileTrue:
This later construct is not easily found in other languages where I often
have to insert a if/break/continue/cycle which is much less expressive.
Normally, you learn #whileTrue: which has many more senders, then once
learned, #whileTrue. shouldn't sound un-natural.

I didn't even notice the presence of doWhileTrue: until today!
I just stumbled upon it while searching for #cacheDuring:.
I think that it's not part of other Smalltalk dialects, never saw it used
in Visualworks, Dolphin.
A vast majority of us should agree that it does not qualify as idiomatic.
IMO it does not add enough value to whileTrue.

>
> > However, I agree that the names are confusing, compared to #whileTrue:
> etc.
> >
> > +1 for naming them #repeatWhile: and #repeatUntil: instead!
> >
> >
> > > But that still means that we have two ways to express exactly the same
> thing, which by first principle should not be
> >
> > > (economy of implementation, of tests, of documentation, etc... small
> is beautiful !).
> >
> > Well, that's another a question of semantics, again. :) Remember my
> examples about #ifNotNil:/#==> etc.? Convenience methods support ease
> of writing and reading.
> >
> > > Really, not kidding?
> > The example is taken from BookMorph >> #saveOnUrlPage:. I did not read
> it in context, too ^^
> >
> > > Is the following better? >
> > > [newPlace := self getNewPlace.
> > > file:= ServerFile new fullPath: newPlace.
> > > file exists] whileTrue
> >
> > In my opinion, #repeatUntil: would still be better :)
> >
> > > Note that I did not add non local block return in the middle of the
> block... > It was in the original method, doWhileTrue did not solve it.
> >
> > I was referring to blockReturn in the bytecode sense. Here is another
> example of confusing blockReturns:
> >
> > (foo satisfiesSomeCondition or: [|baz|
> >     baz := bar asBaz.
> >     foo cacheDuring: [
> >         baz satisfiesSomeOtherCondition]])
> >             ifTrue: [...]
> >
> > Hard to follow the control flow, isn't it? If I have the choice, I avoid
> these statements and use blocks,
>
> Whether or not the above example is okay or not depends on what [...] is.
> For example, if it's simply ^self, then the use of #or: is unnecessary and
> the computation which reduces legibility can be moved out to the main flow
> of the method.
>
> > either) to pass a piece of code to another object and compose control
> flows,
> > or) to explicitly pass a value to be evaluated lazily.
> > Both at once can be confusing. I think there is a good reason why there
> is no syntax for blockReturn like we have one for methodReturn (^).
>
> There is no syntax for blockReturn because it wouldn't be possible to use
> it.
>
>
> Levente
>
> >
> > Best,
> > Christoph
> >
> >
> _________________________________________________________________________________________________________________________________________________________________________________________________________________________________
> > Von: Squeak-dev <squeak-dev-bounces at lists.squeakfoundation.org> im
> Auftrag von Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>
> > Gesendet: Montag, 30. März 2020 20:56:43
> > An: The general-purpose Squeak developers list
> > Betreff: Re: [squeak-dev] #doWhileTrue: (was: The Trunk:
> System-nice.1149.mcz)
> >
> >
> > Le lun. 30 mars 2020 à 19:58, Thiede, Christoph <
> Christoph.Thiede at student.hpi.uni-potsdam.de> a écrit :
> >
> >       Hi Nicolas,
> >
> >
> >       > There is no other sender of doWhileFalse: doWhileTrue: and my
> advice would be to deprecate them. YAGNI.
> >
> >
> > So my image actually contains around two dozen senders of #doWhileTrue:
> and #doWhileFalse: (Squot, Pheno and some of my own code). As mentioned
> somewhere else in the past, I actually like them and find them very useful.
> >
> > In my opinion, many senders of #whileTrue and #whileFalse should be
> refactored to use #doWhileTrue:/#doWhileFalse:. Here is a random example:
> >
> > [newPlace := self getNewPlace.
> > dir := ServerFile new fullPath: newPlace.
> > (dir includesKey: dir fileName)] whileTrue.
> >
> > I find that's ugly and counter-intuitive! I would rewrite this in the
> following way:
> >
> > [newPlace := self getNewPlace.
> > dir := ServerFile new fullPath: newPlace]
> >     doWhileTrue: [dir includesKey: dir fileName].
> >
> >
> > The first thing that upsets me is that they are not idiomatic.
> #whileTrue: and in a lesser way #whileTrue are.
> > The second thing that upsets me is that the names are REALLY too close
> to #whileTrue:
> > So at first, I was confused by the fact that they looked like synonyms.
> > Then I wondered exactly the same, what the hell has to be true?
> > Especially when the sole sender in trunk is [] doWhileTrue: true ;)
> >
> > IMO, they might be better spelled #repeatWhile: and #repeatUntil:
> > But that still means that we have two ways to express exactly the same
> thing, which by first principle should not be
> > (economy of implementation, of tests, of documentation, etc... small is
> beautiful !).
> >
> > We might discuss which is more readable, maybe
> >
> > [newPlace := self getNewPlace.
> > dir := ServerFile new fullPath: newPlace]
> >     repeatWhile: [dir includesKey: dir fileName].
> >
> > is more revealing than:
> >
> > [newPlace := self getNewPlace.
> > dir := ServerFile new fullPath: newPlace.
> > (dir includesKey: dir fileName)] whileTrue.
> >
> > IMO, it's a biased example, because the whole snippet is
> un-comprehensible.
> > So a ServerFile behaves like a ServerDirectory (from which it
> inherits...), oh nice (???).
> > And a ServerFile which would includes some item with same name as itself
> would mean that the file already exists...
> > Really, not kidding?
> >
> > So IMO that's what makes the snippet illegible, not whileTrue.
> > Is the following better?
> >
> > [newPlace := self getNewPlace.
> > file:= ServerFile new fullPath: newPlace.
> > file exists] whileTrue
> >
> > Anyway, the second one is there for such a long time that you can't
> expunge it that easily. It's idiomatic...
> >
> > The latter just reads easier. blockReturns in multi-statement blocks are
> not really intuitive.
> >
> >
> > Note that I did not add non local block return in the middle of the
> block...
> > It was in the original method, doWhileTrue did not solve it.
> >
> >       In the first version, when scanning the method quickly, I read
> "okay, something with places and directories is done, while true ...," I
> wonder "what has to be true?" and have to look back to the end of the block
> >       and find the beginning of the last statement.
> > But in the second version, I read "okay, something with places and
> directories is done, while that directory matches this specific condition."
> This version directly draws my attention to the important condition.
> >
> > Happy to hear your counterarguments :-)
> >
> > Best,
> > Christoph
> >
> >
> _________________________________________________________________________________________________________________________________________________________________________________________________________________________________
> > Von: Squeak-dev <squeak-dev-bounces at lists.squeakfoundation.org> im
> Auftrag von commits at source.squeak.org <commits at source.squeak.org>
> > Gesendet: Montag, 30. März 2020 12:51 Uhr
> > An: squeak-dev at lists.squeakfoundation.org;
> packages at lists.squeakfoundation.org
> > Betreff: [squeak-dev] The Trunk: System-nice.1149.mcz
> > Nicolas Cellier uploaded a new version of System to project The Trunk:
> > http://source.squeak.org/trunk/System-nice.1149.mcz
> >
> > ==================== Summary ====================
> >
> > Name: System-nice.1149
> > Author: nice
> > Time: 30 March 2020, 12:50:26.196366 pm
> > UUID: ece53b0b-24d2-4d4b-bc91-6794a661f886
> > Ancestors: System-ul.1148
> >
> > avoid neuron storming [...] doWhileTrue: true, it just means [...] repeat
> >
> > There is no other sender of doWhileFalse: doWhileTrue: and my advice
> would be to deprecate them. YAGNI.
> >
> > =============== Diff against System-ul.1148 ===============
> >
> > Item was changed:
> >   ----- Method: MOFile>>searchByHash: (in category 'experimental') -----
> >   searchByHash: aString
> >          | hashValue nstr index incr key |
> >          hashValue :=  self hashPjw: aString.
> >          incr := 1 + (hashValue \\ (hashTableSize -2)).
> >          index := (hashValue \\ hashTableSize) .
> >          [        nstr := (hashTable at: index +1 ).
> >                  nstr = 0 ifTrue: [^nil].
> >                  key := self originalString: nstr.
> >                  key = aString ifTrue: [^self translatedString: nstr].
> >                  index >= (hashTableSize - incr)
> >                                  ifTrue: [index := index -
> (hashTableSize - incr)  ]
> >                                  ifFalse:[index := index + incr].
> > +        ] repeat!
> > -        ] doWhileTrue: true.!
> >
> >
> >
> >
> >
>
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