March 2019 - Pharo-users - lists.pharo.org

Re: [Pharo-users] Noob Question - slicing

by Tim Mackinnon

Nice reply Richard - do you ever post any of these in a blog - the one below would be a great one to point to from Exercism... > On 6 Mar 2019, at 12:48, Richard O'Keefe <raoknz(a)gmail.com> wrote: > > As someone else already pointed out, the standard way to copy > part of any array-like sequence is > aSequence copyFrom: firstIncludedIndex to: lastIncludedIndex > > How could you have found this by yourself? > > From the background, either > Click-select Tools-select Playground > or hold Ctrl down while typing OW (for Open Workspace). > In the new Playground/workspace, type > String > then Ctrl-B. You now have a five-pane browser open on > String. > > About half way down the third panel on the top you will see > converting > copying > displaying > Click on copying. > > Guess what? You WON'T see anything that looks relevant! > Maybe it's in an ancestral class. So look at the buttons > under the top row of panes: > All packages Scoped view | Flat Hier | Inst side Class side | ... > Hier looks promising. Click it. > > Now in the second pane you will see > ProtoObject > Object > Collection > SequenceableCollection > ArrayedCollection > String > ... > Select the parent class, ArrayedCollection. > Nope, nothing promising there either! > Select the grandparent class, SequenceableCollection. > And now the 'copying' method category has quite a few > potentially interesting methods, including #copyFrom:to:. > > There are four other related methods that I would argue > are in the wrong category: > allButFirst > allButFirst: count > allButLast > allButLast: count > are in the 'accessing' category. > > If you want something a bit more flexible, > you could add > drop: d take: t > "Discard the first |d| elements of the receiver if d >= 0. > Discard the last |d| elements of the receiver if d <= 0. > Return the first |t| elements of the result if t >= 0. > Return the last |t| elements of the result if t <= 0. > The result is the same kind of collection as the receiver." > |lb ub n| > n := self size. > d abs >= n ifTrue: [^self copyEmpty]. > d < 0 > ifTrue: [lb := 1. ub := n + d] > ifFalse: [lb := d+1. ub := n]. > ub - lb + 1 <= t abs ifFalse: [ > t < 0 > ifTrue: [lb := ub + t + 1] > ifFalse: [ub := lb + t - 1]]. > ^self copyFrom: lb to: ub > > Now I would like to suggest that you not use anything like this > *directly*. Go back to the Playground, and evaluate > > String with: (Character codePoint: 256) <Ctrl-P> > > The answer is 'Ä'. Pharo supports Unicode. Now try > > String with: $A with: (Character codePoint: 16r0304) > > In Pharo, the result looks like A followed by a separate > macron, but when it's pasted into HTML it displays > correctly as 'AÌ'. Pharo doesn't *quite* support Unicode. > If it did, the two strings with different lengths and no > codepoint in common would display exactly the same. > > The Unicode standard finds it necessary to distinguish > between characters, glyphs, graphemes, grapheme clusters, > codepoints, and a couple of other things. A Smalltalk > String is a sequence of *codepoints*, not a sequence of > "characters". There is no upper bound on the number of > codepoints that may be needed to encode one "character" > as the end user sees it, and from there on it gets > *complicated*. > > For over 20 years, it hasn't really made sense to think > of a string as a simply indexed sequence of characters. > Integer indices are a useful implementation-level detail > for remembering bounds from some "higher level" matching > technique, but are much less useful than you might expect. > > > > > > > > On Wed, 6 Mar 2019 at 12:00, Craig Johnson <craig(a)hivemind.net <mailto:craig@hivemind.net>> wrote: > Hi All, > > > > I was trying to figure an elegant way to slice strings (Python style), and came up empty. > > > > What is the simplest way to copy characters between positions 4 and 8 from a string in Pharo? > > > > Craig >

March 6, 2019

Why can't a Bag answer as a dictionary?

by Tim Mackinnon

I was surprised to find that a Bag canât convert to a dictionary - e.g. Bag new addAll: 'aabbbbcdddâ; asDictionary Gives an error - Dnu #key It looks to me like Bag is inheriting a bad version of #associationsDo: and instead could simply forward it to #doWithOccurences: instead? I know Bag is not used that much - but it comes up a lot in programming exercises. Tim

March 6, 2019

Re: [Pharo-users] A "with" construct like Pascal - easy to do, but is it terrible?

by Richard O'Keefe

The Pascal 'with' statement is among the most hated features of Pascal and was not copied in successor languages like Ada or Modula-2. It was typically replaced by record constructors, such as Book1 := Book[title : 'C Programming'; author : 'Nuha Ali '; subject : 'C Programming Tutorial'; book_id : 6495407]; which happens to be Pascal (ISO10206). In self classes do: [:class | | metaclass | metaclass := class metaclass. metaclass xxxx. mataclass yyyy. ] "metaclass" is a a block temporary, not an instance variable, and self classes do: [:each | (each metaclass) xxxx; yyyy]. suffices. We observe that [:x1 ... :xn | ...] value: e1 ... value: en is nothing other than a LET expression wearing a funny hat and should be inlined by a compiler -- mine does -- and that e1 in: [:x1 | ...] is just a "flipped" version of [:x1 | ...] value: e1, so there's no reason why a compiler shouldn't inline that. We also observe that e0 m1; ... ; mn can -- at least in my experience -- be most simply implemented as [:t | t m1. ... t mn] value: e0 followed by the usual inlining of that. So we might expect that some day self classes do: [:each | each metaclass in: [:t | t xxxx. t yyyy]] would generate the *same* code as the cascaded version. Right now, do whichever is clearer. On Tue, 5 Mar 2019 at 02:07, Tim Mackinnon <tim(a)testit.works> wrote: > Iâve noticed that as weâve progressed there has been a move to more > concise and fluid code - e.g. I quite like the new String streaming stuff > > e.g. > > ^ String > streamContents: [ :stream | > stream nextPut: â¦. ] > > > So I was wondering why we donât have a construct like Pascals with to > avoid Book1.title, Book1.author etc. > > (* book 1 specification *)With Book1 dobegin > title := 'C Programming'; > author := 'Nuha Ali '; > subject := 'C Programming Tutorial'; > book_id := 6495407;end; > > > I often find it a bit tedious with code like the following which then > needs an instvar... > > self classes do: [ :class | > | metaclass | > metaclass := class metaclass. > metaclass xxxx. > mataclass yyyy. > ] > > > Iâm wondering why we donât have #with:do: > > class with: class metaclass do: [:metaclass | > metaclass xxx. > ] > > > But when such things arenât there - there is usually a good reason and Iâm > curious â¦ this said, there are all kinds of other such tricks (which I > rarely use that I keep coming across). > > Tim > >

March 6, 2019

Re: [Pharo-users] [Pharo-dev] [ANN] Pharo 7.0.2 released!

by Norbert Hartl

yeah, bright future we come! Norbert > Am 06.03.2019 um 13:01 schrieb Esteban Lorenzano <estebanlm(a)gmail.com>: > > > >> On 6 Mar 2019, at 12:38, Norbert Hartl <norbert(a)hartl.name <mailto:norbert@hartl.name>> wrote: >> >> How wonderful is that? How much effort it was compared to the old process? > > zero. > Bah, I needed to restart the CI because of the freetype random welcome problem. > > Esteban > >> >> Norbert >> >> >>> Am 06.03.2019 um 11:32 schrieb Esteban Lorenzano <estebanlm(a)gmail.com <mailto:estebanlm@gmail.com>>: >>> >>> Hi, >>> >>> I just made a bugfix release of Pharo: >>> >>> v7.0.2 <https://github.com/pharo-project/pharo/releases/tag/v7.0.2> >>> <513630.jpeg> <https://github.com/estebanlm> estebanlm <https://github.com/estebanlm> released this 22 hours ago >>> >>> Bugfix release >>> >>> #2303 <https://github.com/pharo-project/pharo/issues/2303> Deprecation fixes in TEasilyThemed >>> #2120 <https://github.com/pharo-project/pharo/pull/2120> Object-centric MetaLink integration >>> #2376 <https://github.com/pharo-project/pharo/pull/2376> Ensure subMenu is opened (backport) >>> #2428 <https://github.com/pharo-project/pharo/pull/2428> Add scrollSelectionIntoView >>> #2700 <https://github.com/pharo-project/pharo/pull/2700> Tonel test is failing (backport) >>> >>> Enjoy :) >>> >>> Esteban >> >

March 6, 2019

Re: [Pharo-users] Noob Question - slicing

by Richard O'Keefe

As someone else already pointed out, the standard way to copy part of any array-like sequence is aSequence copyFrom: firstIncludedIndex to: lastIncludedIndex How could you have found this by yourself? >From the background, either Click-select Tools-select Playground or hold Ctrl down while typing OW (for Open Workspace). In the new Playground/workspace, type String then Ctrl-B. You now have a five-pane browser open on String. About half way down the third panel on the top you will see converting copying displaying Click on copying. Guess what? You WON'T see anything that looks relevant! Maybe it's in an ancestral class. So look at the buttons under the top row of panes: All packages Scoped view | Flat Hier | Inst side Class side | ... Hier looks promising. Click it. Now in the second pane you will see ProtoObject Object Collection SequenceableCollection ArrayedCollection String ... Select the parent class, ArrayedCollection. Nope, nothing promising there either! Select the grandparent class, SequenceableCollection. And now the 'copying' method category has quite a few potentially interesting methods, including #copyFrom:to:. There are four other related methods that I would argue are in the wrong category: allButFirst allButFirst: count allButLast allButLast: count are in the 'accessing' category. If you want something a bit more flexible, you could add drop: d take: t "Discard the first |d| elements of the receiver if d >= 0. Discard the last |d| elements of the receiver if d <= 0. Return the first |t| elements of the result if t >= 0. Return the last |t| elements of the result if t <= 0. The result is the same kind of collection as the receiver." |lb ub n| n := self size. d abs >= n ifTrue: [^self copyEmpty]. d < 0 ifTrue: [lb := 1. ub := n + d] ifFalse: [lb := d+1. ub := n]. ub - lb + 1 <= t abs ifFalse: [ t < 0 ifTrue: [lb := ub + t + 1] ifFalse: [ub := lb + t - 1]]. ^self copyFrom: lb to: ub Now I would like to suggest that you not use anything like this *directly*. Go back to the Playground, and evaluate String with: (Character codePoint: 256) <Ctrl-P> The answer is 'Ä'. Pharo supports Unicode. Now try String with: $A with: (Character codePoint: 16r0304) In Pharo, the result looks like A followed by a separate macron, but when it's pasted into HTML it displays correctly as 'AÌ'. Pharo doesn't *quite* support Unicode. If it did, the two strings with different lengths and no codepoint in common would display exactly the same. The Unicode standard finds it necessary to distinguish between characters, glyphs, graphemes, grapheme clusters, codepoints, and a couple of other things. A Smalltalk String is a sequence of *codepoints*, not a sequence of "characters". There is no upper bound on the number of codepoints that may be needed to encode one "character" as the end user sees it, and from there on it gets *complicated*. For over 20 years, it hasn't really made sense to think of a string as a simply indexed sequence of characters. Integer indices are a useful implementation-level detail for remembering bounds from some "higher level" matching technique, but are much less useful than you might expect. On Wed, 6 Mar 2019 at 12:00, Craig Johnson <craig(a)hivemind.net> wrote: > Hi All, > > > > I was trying to figure an elegant way to slice strings (Python style), and > came up empty. > > > > What is the simplest way to copy characters between positions 4 and 8 from > a string in Pharo? > > > > Craig >

March 6, 2019

Re: [Pharo-users] [Pharo-dev] [ANN] Pharo 7.0.2 released!

by Esteban Lorenzano

> On 6 Mar 2019, at 12:38, Norbert Hartl <norbert(a)hartl.name> wrote: > > How wonderful is that? How much effort it was compared to the old process? zero. Bah, I needed to restart the CI because of the freetype random welcome problem. Esteban > > Norbert > > >> Am 06.03.2019 um 11:32 schrieb Esteban Lorenzano <estebanlm(a)gmail.com <mailto:estebanlm@gmail.com>>: >> >> Hi, >> >> I just made a bugfix release of Pharo: >> >> v7.0.2 <https://github.com/pharo-project/pharo/releases/tag/v7.0.2> >> <513630.jpeg> <https://github.com/estebanlm> estebanlm <https://github.com/estebanlm> released this 22 hours ago >> >> Bugfix release >> >> #2303 <https://github.com/pharo-project/pharo/issues/2303> Deprecation fixes in TEasilyThemed >> #2120 <https://github.com/pharo-project/pharo/pull/2120> Object-centric MetaLink integration >> #2376 <https://github.com/pharo-project/pharo/pull/2376> Ensure subMenu is opened (backport) >> #2428 <https://github.com/pharo-project/pharo/pull/2428> Add scrollSelectionIntoView >> #2700 <https://github.com/pharo-project/pharo/pull/2700> Tonel test is failing (backport) >> >> Enjoy :) >> >> Esteban >

March 6, 2019

Re: [Pharo-users] [Pharo-dev] [ANN] Pharo 7.0.2 released!

by Norbert Hartl

How wonderful is that? How much effort it was compared to the old process? Norbert > Am 06.03.2019 um 11:32 schrieb Esteban Lorenzano <estebanlm(a)gmail.com>: > > Hi, > > I just made a bugfix release of Pharo: > > v7.0.2 <https://github.com/pharo-project/pharo/releases/tag/v7.0.2> > <513630.jpeg> <https://github.com/estebanlm> estebanlm <https://github.com/estebanlm> released this 22 hours ago > > Bugfix release > > #2303 <https://github.com/pharo-project/pharo/issues/2303> Deprecation fixes in TEasilyThemed > #2120 <https://github.com/pharo-project/pharo/pull/2120> Object-centric MetaLink integration > #2376 <https://github.com/pharo-project/pharo/pull/2376> Ensure subMenu is opened (backport) > #2428 <https://github.com/pharo-project/pharo/pull/2428> Add scrollSelectionIntoView > #2700 <https://github.com/pharo-project/pharo/pull/2700> Tonel test is failing (backport) > > Enjoy :) > > Esteban

March 6, 2019

[ANN] Pharo 7.0.2 released!

by Esteban Lorenzano

Hi, I just made a bugfix release of Pharo: v7.0.2 <https://github.com/pharo-project/pharo/releases/tag/v7.0.2> <https://github.com/estebanlm> estebanlm <https://github.com/estebanlm> released this 22 hours ago Bugfix release #2303 <https://github.com/pharo-project/pharo/issues/2303> Deprecation fixes in TEasilyThemed #2120 <https://github.com/pharo-project/pharo/pull/2120> Object-centric MetaLink integration #2376 <https://github.com/pharo-project/pharo/pull/2376> Ensure subMenu is opened (backport) #2428 <https://github.com/pharo-project/pharo/pull/2428> Add scrollSelectionIntoView #2700 <https://github.com/pharo-project/pharo/pull/2700> Tonel test is failing (backport) Enjoy :) Esteban

March 6, 2019

Re: [Pharo-users] IMAP in Pharo

by CÃ©drick BÃ©ler

Hi Veincent ;-), > Le 6 mars 2019 Ã 10:44, <vincent.blondeau(a)polytech-lille.net> <vincent.blondeau(a)polytech-lille.net> a Ã©crit : > > Hi Cedrik, > > I started something to deal with this as side project: https://github.com/VincentBlondeau/IMAPClient <https://github.com/VincentBlondeau/IMAPClient> > It is at a very early development state. I took a SS3 project (http://smalltalkhub.com/#!/~Gotchas/IMAP-Client <http://smalltalkhub.com/#!/~Gotchas/IMAP-Client>) andbegan to improve it. Nice, I will try. > > Donât hesitate to fork and add some PRs Still havent get my head around this FORK/PR cycle but I will for sure one day :) Iâll try it for sure btw. Thx, CÃ©drick > > Cheers, > Vincent > > From: Pharo-users <pharo-users-bounces(a)lists.pharo.org <mailto:pharo-users-bounces@lists.pharo.org>> On Behalf Of CÃ©drick BÃ©ler > Sent: Wednesday, 6 March 2019 10:37 > To: Any question about pharo is welcome <pharo-users(a)lists.pharo.org <mailto:pharo-users@lists.pharo.org>> > Subject: [Pharo-users] IMAP in Pharo > > Hi all, > > Do you know if IMAP is possible in Pharo ? I havent found any implementation (quick search). > Iâd like to have it to interact/filter my email. POP3 is not really possible. > > I think it would be a nice addition and maybe a good GSOC project ? > > > Cheers, > > CÃ©drick > > http://forum.world.st/Zodiac-and-IMAP-td4741328.html <http://forum.world.st/Zodiac-and-IMAP-td4741328.html> > > It exists in GNU-Smalltalk but donât look at ti, its GPL :-) > https://github.com/gnu-smalltalk/smalltalk/blob/master/packages/net/IMAP.st <https://github.com/gnu-smalltalk/smalltalk/blob/master/packages/net/IMAP.st>

March 6, 2019

Re: [Pharo-users] IMAP in Pharo

by vincent.blondeau＠polytech-lille.net

Hi Cedrik, I started something to deal with this as side project: https://github.com/VincentBlondeau/IMAPClient It is at a very early development state. I took a SS3 project (http://smalltalkhub.com/#!/~Gotchas/IMAP-Client) andbegan to improve it. Donât hesitate to fork and add some PRs Cheers, Vincent From: Pharo-users <pharo-users-bounces(a)lists.pharo.org> On Behalf Of CÃ©drick BÃ©ler Sent: Wednesday, 6 March 2019 10:37 To: Any question about pharo is welcome <pharo-users(a)lists.pharo.org> Subject: [Pharo-users] IMAP in Pharo Hi all, Do you know if IMAP is possible in Pharo ? I havent found any implementation (quick search). Iâd like to have it to interact/filter my email. POP3 is not really possible. I think it would be a nice addition and maybe a good GSOC project ? Cheers, CÃ©drick http://forum.world.st/Zodiac-and-IMAP-td4741328.html It exists in GNU-Smalltalk but donât look at ti, its GPL :-) https://github.com/gnu-smalltalk/smalltalk/blob/master/packages/net/IMAP.st

March 6, 2019