January 2017 - Pharo-dev - lists.pharo.org

Re: [Pharo-dev] memoized vs once

by phil＠highoctane.be

If one is doing any dynamic programming, the memoization term is pretty natural. https://youtu.be/OQ5jsbhAv_M?t=3m11s Phil On Wed, Jan 25, 2017 at 10:30 PM, Igor Stasenko <siguctua(a)gmail.com> wrote: > #once can be interpreted as 'evaluate it once', > > but i don't like the #memoized .. it sounds painful to my ears. > It sounds like something stinking smeared across my face.. and i always > got stuck,confused and lost as the meaning of it always > escaping my mind, since it naturally defends itself from any unpleasant > thoughts. > > IMHO, maybe #once is not the best wording for what it does , but > #memoizing... yuck.. pardon me. > > :) > > > -- > Best regards, > Igor Stasenko. >

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by phil＠highoctane.be

All that is nice but I only found about it because I searched for "memoize"... Which is what it does. Phil On Wed, Jan 25, 2017 at 9:29 PM, Nicolas Cellier < nicolas.cellier.aka.nice(a)gmail.com> wrote: > Hi Eliot, > you should have named the thread "once for all!" > +1 in any case > > 2017-01-25 19:56 GMT+01:00 Eliot Miranda <eliot.miranda(a)gmail.com>: > >> Hi Ben, >> >> via FaceBook via twitter I hear you've coined >> BlockClosure>>#memoized. Allow me to beg you to rename it to >> BlockClosure>>#once. There's a preexisting implementation of this in >> VisualWorks by Travis Griggs called once. I hope you agree that it's good >> to eliminate gratuitous incompatibilities between dialects and that "once" >> is an elegant name. >> _,,,^..^,,,_ >> best, Eliot >> > >

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by Torsten Bergmann

Hi, >From my perspective: - I agree with Igor that "once" can be interpreted as "evaluate it only once" as inÂ Â Â "Halt once". - I'm not sure but from the (now very distributed) discussion it is not clear to me if the #once mentioned by Eliot really has exactly the same behavior as #memoized in Pharo. Does it also return a block that is caching the results and avoids a second evalution of the original block when having similar inputs? Also is there a similar possibility to give an own cache as in #memoizedUsing: for further tuning? - #memoizing is really not well explaining what it does but this seems to be the official Â term (also in other languages like Python, Java, JS, ...):Â https://en.wikipedia.org/wiki/Memoization -Â maybeÂ #withMemo(r)izingResults or #withCachingResults,Â #withReusedResults, ... or something along that line Â Â would be more intention revealing selectors Side note: ========= - For license reason it would not make much sense to look into non-open Smalltalks - I have no idea about the VW version (and for obvious reasons dont want to have a look) - also dont know about other dialects if they have built in support for memoization but it would be good if Squeak, Pharo, Cuis, ... could align for such a case - IMHO if #once and Pharos #memoization really have the same behavior then compatibility for VW users Â Â could be easily retained by adding #once to existing compatibility layers (like "Grease") Bye T. Gesendet:Â Mittwoch, 25. Januar 2017 um 22:30 Uhr Von:Â "Igor Stasenko" <siguctua(a)gmail.com> An:Â "Pharo Development List" <pharo-dev(a)lists.pharo.org> Betreff:Â Re: [Pharo-dev] memoized vs once #once can be interpreted as 'evaluate it once', Â but i don't like the #memoized .. it sounds painful to my ears. It sounds like something stinking smeared across my face.. and i always got stuck,confused and lost as the meaning of it alwaysÂ escaping my mind, since it naturally defends itself from any unpleasant thoughts. IMHO, maybe #once is not the best wording for what it does , but #memoizing... yuck.. pardon me. Â Â :) Â Â -- Best regards, Igor Stasenko.

Jan. 25, 2017

Re: [Pharo-dev] Pharo by Example 50 released!

by Stephan Eggermont

On 22/01/17 16:53, stepharong wrote: > https://pharoweekly.wordpress.com/2017/01/22/pharo-by-example-50-released/ > > Super special thanks to Nicolai Hess that pushed me to do the last steps > to release. > Thanks Nicolai your steady commits pushed me! Great. Having an up to date introduction like this is crucial to attracting new people to the community. Well done! Stephan

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by Igor Stasenko

#once can be interpreted as 'evaluate it once', but i don't like the #memoized .. it sounds painful to my ears. It sounds like something stinking smeared across my face.. and i always got stuck,confused and lost as the meaning of it always escaping my mind, since it naturally defends itself from any unpleasant thoughts. IMHO, maybe #once is not the best wording for what it does , but #memoizing... yuck.. pardon me. :) -- Best regards, Igor Stasenko.

Jan. 25, 2017

Re: [Pharo-dev] Immutability support

by Denis Kudriashov

2017-01-25 22:24 GMT+01:00 Denis Kudriashov <dionisiydk(a)gmail.com>: > For the Process hack, it's because the call-back was designed to return no >> value. > > > Now I am confused. > Why anybody needs to return value from this method? > And why there is "CAN'T REACH" comment at the end of method? > Do you mean that method should never return? > > >> It may look like it works when returning a value but you will have >> uncommon crashes. > > And is it safe to just signal error?

Jan. 25, 2017

Re: [Pharo-dev] Immutability support

by Denis Kudriashov

2017-01-25 18:23 GMT+01:00 ClÃ©ment Bera <bera.clement(a)gmail.com>: > For the Process hack, it's because the call-back was designed to return no > value. Now I am confused. Why anybody needs to return value from this method? And why there is "CAN'T REACH" comment at the end of method? Do you mean that method should never return? > It may look like it works when returning a value but you will have > uncommon crashes. That's fun :)

Jan. 25, 2017

Re: [Pharo-dev] Pharo by Example 50 released!

by monty

This is great news. An up to date PBE is one of the best ways to get people into Pharo. > Sent: Sunday, January 22, 2017 at 10:53 AM > From: stepharong <stepharong(a)free.fr> > To: pharo-dev(a)lists.pharo.org > Cc: pharo-users(a)lists.pharo.org > Subject: [Pharo-dev] Pharo by Example 50 released! > > https://pharoweekly.wordpress.com/2017/01/22/pharo-by-example-50-released/ > > Super special thanks to Nicolai Hess that pushed me to do the last steps > to release. > Thanks Nicolai your steady commits pushed me! > > Stef > >

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by Denis Kudriashov

Hi Eliot. 2017-01-25 19:56 GMT+01:00 Eliot Miranda <eliot.miranda(a)gmail.com>: > Hi Ben, > > via FaceBook via twitter I hear you've coined > BlockClosure>>#memoized. Allow me to beg you to rename it to > BlockClosure>>#once. There's a preexisting implementation of this in > VisualWorks by Travis Griggs called once. I hope you agree that it's good > to eliminate gratuitous incompatibilities between dialects and that "once" > is an elegant name. > #once is not the same as #memoized. #memoized returns another block which wrap original one to perform some caching. Actually I not understand logic behind it. But #once supposed to evaluate receiver while #memoized creates new block. In Pharo 6 I pushed new method #asMethodConst. Unfortunately I was not aware about #once from VisualWorks at this time and reviewers too. But #asMethodConst is a bit different. It is Object method instead of Block. And it is based on AST modification. When asMethodConst is executed it replace executing AST-node of sender with receiver which produce new method where full message node is replaced by result as literal. I put mode details here http://dionisiydk.blogspot.fr/2016/07/magic-with-pharo-reflectivity.html. In short you can write expressions like: 10 factorial asMethodConst

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by Nicolas Cellier

Hi Eliot, you should have named the thread "once for all!" +1 in any case 2017-01-25 19:56 GMT+01:00 Eliot Miranda <eliot.miranda(a)gmail.com>: > Hi Ben, > > via FaceBook via twitter I hear you've coined > BlockClosure>>#memoized. Allow me to beg you to rename it to > BlockClosure>>#once. There's a preexisting implementation of this in > VisualWorks by Travis Griggs called once. I hope you agree that it's good > to eliminate gratuitous incompatibilities between dialects and that "once" > is an elegant name. > _,,,^..^,,,_ > best, Eliot >

Jan. 25, 2017