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

Re: [Pharo-users] Zinc - multipart forms query

by Sven Van Caekenberghe

Hi Ben, Try: ZnClient new systemPolicy; beOneShot; url: 'http://dpaste.com/api/v2/'; addPart: (ZnMimePart fieldName: 'syntax' value: 'smalltalk'); addPart: (ZnMimePart fieldName: 'content' value: 'hello; world'); post. Although curl is powerful, well known and well supported, I would not say it is a great standard for interface design, it is way too complex. Zn tries to approach HTTP from an object design standpoint. You pass along a ZnMultiPartFormDataEntity object that contains ZnMimeParts as entity to your POST request. Sven > On 17 May 2019, at 05:26, Ben Coman <btc(a)openinworld.com> wrote: > > We are trying to replicate the following in Pharo... > $ echo "hello; world" | curl -s -F "syntax=smalltalk" -F "content=<-" http://dpaste.com/api/v2/ > > like this... > url := ZnClient new > logToTranscript; > systemPolicy; > beOneShot; > url: 'http://dpaste.com/api/v2/'; > formAt: 'syntax' put: 'smalltalk'; > formAt: 'content' put: 'hello; world'; > post. > > Curl produces... "hello; world" > http://dpaste.com/2Y15WGY > but Zinc produces only... "hello" > http://dpaste.com/28E974Y > > The difference is apparent on the wire... > With curl... > <image.png> > > With Zinc... > <image.png> > > The curl manpage says... > -F, --form <name=content> > For HTTP protocol family, this lets curl emulate a filled-in form in which > a user has pressed the submit button. This causes curl to POST data > using the Content-Type multipart/form-data according to RFC 2388. > > So we've used multipart forms elsewhere already... > https://github.com/exercism/pharo-smalltalk/blob/4a88c397/dev/src/ExercismT… > https://github.com/exercism/pharo-smalltalk/blob/4a88c397/dev/src/ExercismT… > https://github.com/exercism/pharo-smalltalk/blob/9c6b91aaf/dev/src/Exercism… > https://github.com/exercism/pharo-smalltalk/blob/0e0bd82ed/dev/src/Exercism… > > so I'm sure we can achieve what we want, just curious if there might be > any convenience methods that could be used similar to the examples > given on the rest of curl's "-F" description. > Or if there could be? Curl examples are often used for reference by APIs (http://dpaste.com/api/v2/) > and a close map between curl and Zinc would be really great. > > cheers -ben > > P.S. I even wonder if a ZnCurl would be useful that parsed curl strings. > This would firstly provide ease of use for newcomers, > and secondly define how to map through to native Zinc methods.

May 17, 2019

Pharo Launcher could select newly created image (to be played) by default

by Christopher Fuhrman

I posted a feature request at https://github.com/pharo-project/pharo-launcher/issues/339

May 17, 2019

Re: [Pharo-users] Bloc of code in tiers programming language

by Richard O'Keefe

I did not mean "course of instruction on the topic of continuations", I meant "that class whose name is Continuation in the Smalltalk image." In a Playground, type Continuation and then Control-B. On Fri, 17 May 2019 at 14:03, Brainstorms <wild.ideas(a)gmail.com> wrote: > Richard O'Keefe wrote > > Blocks in current Smalltalk system are just like lambdas in Scheme. > > Pharo even has continuations (see the Continuation class). > > I was going to ask about coroutines and continuations, but I thought maybe > bringing these subjects up in another thread would be more appropriate. > (This forum is also new to me. More so than Smalltalk & Pharo.) > > Is the "Continuation class" part of the MOOC series? Or a class held at > the > ESUG conference? I don't recall running across anything referring to the > subject. > > -t > > > > > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > >

May 17, 2019

Zinc - multipart forms query

by Ben Coman

We are trying to replicate the following in Pharo... $ echo "hello; world" | curl -s -F "syntax=smalltalk" -F "content=<-" http://dpaste.com/api/v2/ like this... url := ZnClient new logToTranscript; systemPolicy; beOneShot; url: 'http://dpaste.com/api/v2/'; formAt: 'syntax' put: 'smalltalk'; formAt: 'content' put: 'hello; world'; post. Curl produces... "hello; world" http://dpaste.com/2Y15WGY but Zinc produces only... "hello" http://dpaste.com/28E974Y The difference is apparent on the wire... With curl... [image: image.png] With Zinc... [image: image.png] The curl manpage says... -F, --form <name=content> For HTTP protocol family, this lets curl emulate a filled-in form in which a user has pressed the submit button. This causes curl to POST data using the Content-Type multipart/form-data according to RFC 2388. So we've used multipart forms elsewhere already... https://github.com/exercism/pharo-smalltalk/blob/4a88c397/dev/src/ExercismT… <https://github.com/exercism/pharo-smalltalk/blob/4a88c397e550f1319b7be4dbff…> https://github.com/exercism/pharo-smalltalk/blob/4a88c397/dev/src/ExercismT… <https://github.com/exercism/pharo-smalltalk/blob/4a88c397e550f1319b7be4dbff…> https://github.com/exercism/pharo-smalltalk/blob/9c6b91aaf/dev/src/Exercism… <https://github.com/exercism/pharo-smalltalk/blob/9c6b91aa9fd10ae1efdfa779e0…> https://github.com/exercism/pharo-smalltalk/blob/0e0bd82ed/dev/src/Exercism… <https://github.com/exercism/pharo-smalltalk/blob/0e0bd82ed74c9966d2375d9392…> so I'm sure we can achieve what we want, just curious if there might be any convenience methods that could be used similar to the examples given on the rest of curl's "-F" description. Or if there could be? Curl examples are often used for reference by APIs ( http://dpaste.com/api/v2/) and a close map between curl and Zinc would be really great. cheers -ben P.S. I even wonder if a ZnCurl would be useful that parsed curl strings. This would firstly provide ease of use for newcomers, and secondly define how to map through to native Zinc methods.

May 17, 2019

Re: [Pharo-users] Bloc of code in tiers programming language

by Brainstorms

Richard O'Keefe wrote > Blocks in current Smalltalk system are just like lambdas in Scheme. > Pharo even has continuations (see the Continuation class). I was going to ask about coroutines and continuations, but I thought maybe bringing these subjects up in another thread would be more appropriate. (This forum is also new to me. More so than Smalltalk & Pharo.) Is the "Continuation class" part of the MOOC series? Or a class held at the ESUG conference? I don't recall running across anything referring to the subject. -t -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

May 17, 2019

Re: [Pharo-users] Bloc of code in tiers programming language

by Richard O'Keefe

Blocks in current Smalltalk system are just like lambdas in Scheme. Pharo even has continuations (see the Continuation class). On Fri, 17 May 2019 at 05:21, Brainstorms <wild.ideas(a)gmail.com> wrote: > I beg your pardon.. and thank you for being the first to draw my attention > to > the fact that the phrase (a common enough American colloquialism) is > actually a logical fallacy. Until now, it's been strictly idiomatic to me. > > And thank you for your prompt reply. > > Am I safe to assume that blocks in Smalltalk, as with Lua, capture their > locally-scoped variables (referred to in Lua as "non-local variables") for > correct evaluation in other contexts, such as when blocks are passed as > arguments and return values? I.e., cases where the local variables of a > method have gone out of scope and no longer exist, yet are referenced > within > the block at some future time when evaluated. I expect so; I just haven't > seen it described in this detail. > > -t > > > > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > >

May 17, 2019

Small query about ZnClient post - with "; " form values

by Tim Mackinnon

I was trying to automate posting some values to a website (I would use Stfx.eu but it doesnât do syntax highlighting and only seems to work for quite small amounts). Anyway the following code always seems to trim values that have a ; in them - and Iâm wondering if Iâm missing something - or if its the endpoint that has an issue (although curl seems to work fine). content := 'hello world; hello'. ZnClient new systemPolicy; beOneShot; url: 'http://dpaste.com/api/v2/'; formAt: 'title' put: 'my; title'; formAt: 'syntax' put: 'smalltalk'; formAt: 'expiry_days' put: '5'; formAt: 'content' put: content; post. Tim

May 17, 2019

Re: [Pharo-users] can I do this with a stream or a format

by Richard O'Keefe

stream := WriteStream on: (String new: gifts size * "estimated size per gift" 10). "The number after #new: is the *initial* allocation; the stream will reallocate it as needed." gifts allButLastDo: [:each | stream nextPutAll: each; nextPutAll: ', ']. stream nextPutAll: 'and '; nextPutAll: gifts last. ^stream contents Using #allButLastDo: saves making a copy of (most of) gifts. How could you find out about these things? You want to join some strings, so you look for a "join" method in String and you will find join: aCollection ^ self class new: (aCollection size * self size) streamContents: [:stream | aCollection do: [:each | stream nextPutAll: each asString] separatedBy: [stream nextPutAll: self]] You might wonder if there is already something close to what you want, so you might enter "commas" into Spotter. If you did that, you would find Collection>>asCommaStringAnd so that the whole thing is very nearly gifts asCommaStringAnd Just as the concatenation selector #, works with most kinds of sequences, so building sequences up using a WriteStream works with most kinds of sequences. Let's work through a little example. We are just going to build up the string 'Quick' one character at a time. s := ''. s := s , 'Q'. "creates a new string holding 'Q'" s := s , 'u'. "creates a new string holding 'Qu'" s := s , 'i'. "creates a new string holding 'Qui'" s := s , 'c'. "creates a new string holding 'Quic'" s := s , 'k'. "creates a new string holding 'Quick'" You see that building a string of n characters will actually create n new strings, all but the last of which will be thrown away, taking O(n**2) time. Now let's use a stream. w := WriteStream on: (String new: 4). "Yes, I know that's too small." w nextPutAll: 'Q'. "The stream now holds 'Q...' in its buffer." w nextPutAll: 'u'. "The stream now holds 'Qu..' in its buffer." w nextPutAll: 'i'. "The stream now holds 'Qui.' in its buffer." w nextPutAll: 'c'. "The stream now holds 'Quic' in its buffer." s nextPutAll: 'k'. "There is no room left in the buffer, so the stream allocates a new buffer twice the size and copies the old one into it. Now it has 'Quic....' and it has room. The stream now holds 'Quick...' in its buffer." s := w contents. "We are asking for the defined elements of the buffer. This means s := buffer copyFrom: 1 to: w position." You see that building a string of n characters this way requires a minimum of two strings, the buffer and the final result. The buffer may be periodically resized, but growing by doubling means the average cost is still O(n). Let's time these to get an idea. Time millisecondsToRun: [ |s| s := ''. 1 to: 10000 do: [:i | s := s , i printString]. s size] => 124 Time millisecondsToRun: [ |w| w := WriteStream on: (String new: 10000). 1 to: 10000 do: [:i | w nextPutAll: i printString]. w contents size] => 7 This is exactly the reason that Java has both String and StringBuilder. The tragedy of Java (well, not the only one) is that they had the example of Smalltalk before them, showing very very clearly that the best way to handle object to text conversion is to use #printOn: as the primitive, not #printString, and they *still* went ahead and did the worse thing. (Ruby has even less excuse for privileging to_s.) There are quite a few books about Smalltalk available as free PDFs from the Pharo web site, a wonderful resource. The Blue Book (Smalltalk-80 The Language and its Implementation) describes streams in Chapter 12. On Fri, 17 May 2019 at 07:21, Roelof Wobben <r.wobben(a)home.nl> wrote: > Hello, > > Im testing all my solutions with critiz and can solve almost all problems, > > Only this one I cannot figure out. > > I have this code > > (gifts allButLast > inject: '' > into: [ :str :each | str , each , ', ' ]) , 'and ' , gifts last ] > > and critiz says I should use a stream . > > How can I make this work ? > > Roelof > > >

May 17, 2019

Re: [Pharo-users] can I do this with a stream or a format

by Roelof Wobben

May 16, 2019

Re: [Pharo-users] can I do this with a stream or a format

by Esteban Maringolo

Oh... the expected output was 'e1, e2, e3 and e4', I read "all" instead of "and". Now it makes sense. Esteban A. Maringolo On Thu, May 16, 2019 at 5:09 PM Roelof Wobben <r.wobben(a)home.nl> wrote: > and this is working > > String > streamContents: [ :stream | > gifts allButLast > do: [ :each | stream nextPutAll: each ] > separatedBy: [ stream > nextPut: $,; > space ]. > stream > nextPut: $,; > nextPutAll: ' and '; > nextPutAll: gifts last ] ] > > Thanks Estaban for the hint. > > Roelof > > > > Op 16-5-2019 om 21:51 schreef Roelof Wobben: > > I think this is better > > ^ String streamContents: [:stream | > > gifts > do: [:each | stream nextPutAll: each ] > separatedBy: [ stream nextPut: $,; space ] > stream nextputAll: 'all'; nextPut: ','; nextPut: gifts last] > > > > Op 16-5-2019 om 21:47 schreef Roelof Wobben: > > oke, and then do something like : > > stream := > > String streamContents: [:stream | gifts > do: [:each | stream nextPutAll: each ] > separatedBy: [ stream nextPut: $,; space ] > > > > stream nextputAll: 'all'; nextPut: ','; nextPut: gifts last > > ] > > stream nextputAll: 'all' > stream nextPut: ',' > stream nextPut: gifts last > > > Roelof > > > > Op 16-5-2019 om 21:30 schreef Esteban Maringolo: > > Maybe this is a better way to build what you want. > > String streamContents: [:stream | gifts > do: [:each | stream nextPutAll: each ] > separatedBy: [ stream nextPut: $,; space ] > ] > > Esteban A. Maringolo > > > On Thu, May 16, 2019 at 4:21 PM Roelof Wobben <r.wobben(a)home.nl> wrote: > >> Hello, >> >> Im testing all my solutions with critiz and can solve almost all problems, >> >> Only this one I cannot figure out. >> >> I have this code >> >> (gifts allButLast >> inject: '' >> into: [ :str :each | str , each , ', ' ]) , 'and ' , gifts last ] >> >> and critiz says I should use a stream . >> >> How can I make this work ? >> >> Roelof >> >> >> > > >

May 16, 2019