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Re: [Pharo-project] 'foo' asTime

by Guillermo Polito

And now, because of fixing Integer>>readFrom:, 'foo' asTime throws an exception and we all are a bit happier :D. On Wed, Aug 25, 2010 at 7:55 PM, Schwab,Wilhelm K <bschwab(a)anest.ufl.edu>wrote: > I would like to be *able* to use a read method to pull from a stream with > other data in it. Whether it needs to be at the end when that is over is > open for debate, perhaps left to the caller?? It is an important question. > Off the top of my head, it seems that Dolphin somewhat dodges it for dates > and times by taking strings. I can check on whether they raise errors if > there is "stuff left over." > > Again, I am fully supportive of raising errors by default. They help to > fix a lot more trouble than they cause. > > > ________________________________________ > From: pharo-project-bounces(a)lists.gforge.inria.fr [ > pharo-project-bounces(a)lists.gforge.inria.fr] On Behalf Of Nicolas Cellier > [nicolas.cellier.aka.nice(a)gmail.com] > Sent: Wednesday, August 25, 2010 4:50 PM > To: Pharo-project(a)lists.gforge.inria.fr > Subject: Re: [Pharo-project] 'foo' asTime > > 2010/8/25 StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>: > > Hi nicolas > > > > If I understand you correctly we are in sync. > > Yes readFrom: should read or fails raising an Error > > and we should use Integer readFrom: 'foo' ifFail: [the default value that > the client knows that he wants] > > > > Now we integrated your number parsers so this is strange that the > behavior is not like you mention > > did you make them backwards compatible? > > > > So I would give a try to get readFrom: clean. > > Johan please give a try > > > > Stef > > > > Yes, all the infrastructure is there, just change the top message to > be awkward-uncompatible ;) like Guillermo is suggesting. > > See also my other suggestion: implement #readFrom:ifFail: in every > class instead of #readFrom: and let readFrom default implementation to > just be > ^self readFrom: aStream ifFail: [self error: 'invalid format'] > > One question I'm not sure about is whether we should distinguish 2 API's: > - one for reading a single object and bark on extra-characters - IMO, > this would be the correct Behaviour of #readFromString: > - one for reading an object in a longer sequence of objects (just keep > the stream positionned after last character read) - this would be > readFrom: aStream > > Nicolas > > > > > > > >> In squeak, (Integer readFromString: 'foo') ->Error > >> > >> Use: > >> - Integer readFrom: 'foo' ifFail: [0], tp get backward compatibility, > >> - (Integer readFrom: 'foo' ifFail: []), to get nil > >> > >> Though it is possible, I dislike anwsering nil, because it would mean > >> a bunch of #readFrom: send should be protected by #ifNil: Blocks... > >> 1) That's nonsense, readFrom:ifFail: already does the work. > >> 2) you cripple the code with Error conditions and end up with > >> unreadable C-looking like code > >> (3 lines of Error condition crap for 1 line of underlying algorithm > >> at every function call) > >> 3) Exception handling can avoid long chains of ifFail: / ifNil: tests > >> > >> But that conversation already took place many times... > >> > >> I'd like the readFrom:ifFail: form to be generalized to other objects, > >> with default behaviour raising an Error. What do you think ? > >> > >> Nicolas > >> > >> 2010/8/24 Johan Brichau <johan(a)inceptive.be>: > >>> > >>> On 24 Aug 2010, at 15:19, StÃ©phane Ducasse wrote: > >>> > >>>> I thought that readFromString: was raising an error and that > guessNumber* was returning zero > >>> > >>> I thought that too. I even have application code that shows that this > used to return nil in some version of Pharo... > >>> But: > >>> > >>> 'foo' asInteger = nil > >>> Integer readFromString: 'foo' = 0 > >>> 'foo' asNumber -> Error > >>> > >>> aargh :-( > >>> > >>> disclaimer: currently testing this in pharo1.1 > >>> > >>> Johan > >>> _______________________________________________ > >>> Pharo-project mailing list > >>> Pharo-project(a)lists.gforge.inria.fr > >>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > >>> > >> > >> _______________________________________________ > >> Pharo-project mailing list > >> Pharo-project(a)lists.gforge.inria.fr > >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > > > > > _______________________________________________ > > Pharo-project mailing list > > Pharo-project(a)lists.gforge.inria.fr > > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >

Aug. 26, 2010

Re: [Pharo-project] 'foo' asTime

by Schwab,Wilhelm K

I would like to be *able* to use a read method to pull from a stream with other data in it. Whether it needs to be at the end when that is over is open for debate, perhaps left to the caller?? It is an important question. Off the top of my head, it seems that Dolphin somewhat dodges it for dates and times by taking strings. I can check on whether they raise errors if there is "stuff left over." Again, I am fully supportive of raising errors by default. They help to fix a lot more trouble than they cause. ________________________________________ From: pharo-project-bounces(a)lists.gforge.inria.fr [pharo-project-bounces(a)lists.gforge.inria.fr] On Behalf Of Nicolas Cellier [nicolas.cellier.aka.nice(a)gmail.com] Sent: Wednesday, August 25, 2010 4:50 PM To: Pharo-project(a)lists.gforge.inria.fr Subject: Re: [Pharo-project] 'foo' asTime 2010/8/25 StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>: > Hi nicolas > > If I understand you correctly we are in sync. > Yes readFrom: should read or fails raising an Error > and we should use Integer readFrom: 'foo' ifFail: [the default value that the client knows that he wants] > > Now we integrated your number parsers so this is strange that the behavior is not like you mention > did you make them backwards compatible? > > So I would give a try to get readFrom: clean. > Johan please give a try > > Stef > Yes, all the infrastructure is there, just change the top message to be awkward-uncompatible ;) like Guillermo is suggesting. See also my other suggestion: implement #readFrom:ifFail: in every class instead of #readFrom: and let readFrom default implementation to just be ^self readFrom: aStream ifFail: [self error: 'invalid format'] One question I'm not sure about is whether we should distinguish 2 API's: - one for reading a single object and bark on extra-characters - IMO, this would be the correct Behaviour of #readFromString: - one for reading an object in a longer sequence of objects (just keep the stream positionned after last character read) - this would be readFrom: aStream Nicolas > > >> In squeak, (Integer readFromString: 'foo') ->Error >> >> Use: >> - Integer readFrom: 'foo' ifFail: [0], tp get backward compatibility, >> - (Integer readFrom: 'foo' ifFail: []), to get nil >> >> Though it is possible, I dislike anwsering nil, because it would mean >> a bunch of #readFrom: send should be protected by #ifNil: Blocks... >> 1) That's nonsense, readFrom:ifFail: already does the work. >> 2) you cripple the code with Error conditions and end up with >> unreadable C-looking like code >> (3 lines of Error condition crap for 1 line of underlying algorithm >> at every function call) >> 3) Exception handling can avoid long chains of ifFail: / ifNil: tests >> >> But that conversation already took place many times... >> >> I'd like the readFrom:ifFail: form to be generalized to other objects, >> with default behaviour raising an Error. What do you think ? >> >> Nicolas >> >> 2010/8/24 Johan Brichau <johan(a)inceptive.be>: >>> >>> On 24 Aug 2010, at 15:19, StÃ©phane Ducasse wrote: >>> >>>> I thought that readFromString: was raising an error and that guessNumber* was returning zero >>> >>> I thought that too. I even have application code that shows that this used to return nil in some version of Pharo... >>> But: >>> >>> 'foo' asInteger = nil >>> Integer readFromString: 'foo' = 0 >>> 'foo' asNumber -> Error >>> >>> aargh :-( >>> >>> disclaimer: currently testing this in pharo1.1 >>> >>> Johan >>> _______________________________________________ >>> Pharo-project mailing list >>> Pharo-project(a)lists.gforge.inria.fr >>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >>> >> >> _______________________________________________ >> Pharo-project mailing list >> Pharo-project(a)lists.gforge.inria.fr >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > _______________________________________________ Pharo-project mailing list Pharo-project(a)lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project

Aug. 25, 2010

[Pharo-project] Experimental Cocoa OS-X based Squeak Cog JIT VM 5.8b3.

by John M McIntosh

I've stuck a version (5.8b3) of the cocoa based os-x squeak cog JIT based VM in my experimental folder. http://homepage.mac.com/johnmci/.Public/experimental/Squeak%205.8b3.app.zip This VM is built from the Cog sources (with some minor changes for the iPhone) & revised & fixed Socket Plugin. It currently does NOT contain any external plugins. I did check in the changes to squeakvm.org that are required to build this VM excluding the required Cog changes... People are invited to take it for a whirl, report any performance gains, issues and especially crashes. PS (a) yes shortly we'll get the iPhone changes folded back into the source tree so you can build the VM. (b) yes when resizing a window you get neat graphic effects (fixing that issue is non-trival). (c) As time permits we'll look into rebuild this rather long list of plugins. ClipboardExtendedPlugin.bundle CroquetPlugin.bundle CurlPlugin.bundle FloatMathPlugin.bundle FT2Plugin.bundle IA32ABI.bundle KedamaPlugin.bundle KedamaPlugin2.bundle LocalePlugin.bundle mpeg3Plugin.bundle ObjectiveCPlugin.bundle OggPlugin.bundle PrintJobPlugin.bundle QuicktimePlugin.bundle RomePlugin.bundle SerialExtendedUnixPlugin.bundle ServicesPlugin.bundle SpellingPlugin.bundle SqueakFFIPrims.bundle TestOSAPlugin.bundle UnixOSProcessPlugin.bundle -- =========================================================================== John M. McIntosh <johnmci(a)smalltalkconsulting.com> Twitter: squeaker68882 Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com ===========================================================================

Aug. 25, 2010

Re: [Pharo-project] 'foo' asTime

by Schwab,Wilhelm K

Stef, I was so happy to see somebody ringing the "don't return nil; raise an exception" alram that I completely missed the time (and date?) connection. Any #readFrom:* method will be inadequate due to formats. Dolphin tackles thiat with type converters, and I have a minimal set that I fully intend to grow. See http://squeaksource.com/PharoInbox/DolphinCompatibility-ValueAdapters-BillS… and repeat after me: Caveat Emptor. Beyond that, if the code runs w/o my streams enhancements installed, please let me know - I would consider that a horrible bug. Bill ________________________________________ From: pharo-project-bounces(a)lists.gforge.inria.fr [pharo-project-bounces(a)lists.gforge.inria.fr] On Behalf Of StÃ©phane Ducasse [stephane.ducasse(a)inria.fr] Sent: Wednesday, August 25, 2010 5:00 PM To: Pharo-project(a)lists.gforge.inria.fr Subject: Re: [Pharo-project] 'foo' asTime http://code.google.com/p/pharo/issues/detail?id=2859 Stef _______________________________________________ Pharo-project mailing list Pharo-project(a)lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project

Aug. 25, 2010

Re: [Pharo-project] 'foo' asTime

by StÃ©phane Ducasse

http://code.google.com/p/pharo/issues/detail?id=2859 Stef

Aug. 25, 2010

Re: [Pharo-project] 'foo' asTime

by StÃ©phane Ducasse

On Aug 25, 2010, at 10:50 PM, Nicolas Cellier wrote: > 2010/8/25 StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>: >> Hi nicolas >> >> If I understand you correctly we are in sync. >> Yes readFrom: should read or fails raising an Error >> and we should use Integer readFrom: 'foo' ifFail: [the default value that the client knows that he wants] >> >> Now we integrated your number parsers so this is strange that the behavior is not like you mention >> did you make them backwards compatible? >> >> So I would give a try to get readFrom: clean. >> Johan please give a try >> >> Stef >> > > Yes, all the infrastructure is there, just change the top message to > be awkward-uncompatible ;) like Guillermo is suggesting. I integrated the changes of guillermo. But readFrom:ifFail: is a nice API. > See also my other suggestion: implement #readFrom:ifFail: in every > class instead of #readFrom: and let readFrom default implementation to > just be > ^self readFrom: aStream ifFail: [self error: 'invalid format'] > > One question I'm not sure about is whether we should distinguish 2 API's: > - one for reading a single object and bark on extra-characters - IMO, > this would be the correct Behaviour of #readFromString: > - one for reading an object in a longer sequence of objects (just keep > the stream positionned after last character read) - this would be > readFrom: aStream Yes. I was thinking about something in the same vein so that we could walk on the stream Now I think that we should get a concrete case to learn from. First raising an error instead of zero is a good behavior and it may break some code. Stef >> >> >>> In squeak, (Integer readFromString: 'foo') ->Error >>> >>> Use: >>> - Integer readFrom: 'foo' ifFail: [0], tp get backward compatibility, >>> - (Integer readFrom: 'foo' ifFail: []), to get nil >>> >>> Though it is possible, I dislike anwsering nil, because it would mean >>> a bunch of #readFrom: send should be protected by #ifNil: Blocks... >>> 1) That's nonsense, readFrom:ifFail: already does the work. >>> 2) you cripple the code with Error conditions and end up with >>> unreadable C-looking like code >>> (3 lines of Error condition crap for 1 line of underlying algorithm >>> at every function call) >>> 3) Exception handling can avoid long chains of ifFail: / ifNil: tests >>> >>> But that conversation already took place many times... >>> >>> I'd like the readFrom:ifFail: form to be generalized to other objects, >>> with default behaviour raising an Error. What do you think ? >>> >>> Nicolas >>> >>> 2010/8/24 Johan Brichau <johan(a)inceptive.be>: >>>> >>>> On 24 Aug 2010, at 15:19, StÃ©phane Ducasse wrote: >>>> >>>>> I thought that readFromString: was raising an error and that guessNumber* was returning zero >>>> >>>> I thought that too. I even have application code that shows that this used to return nil in some version of Pharo... >>>> But: >>>> >>>> 'foo' asInteger = nil >>>> Integer readFromString: 'foo' = 0 >>>> 'foo' asNumber -> Error >>>> >>>> aargh :-( >>>> >>>> disclaimer: currently testing this in pharo1.1 >>>> >>>> Johan >>>> _______________________________________________ >>>> Pharo-project mailing list >>>> Pharo-project(a)lists.gforge.inria.fr >>>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >>>> >>> >>> _______________________________________________ >>> Pharo-project mailing list >>> Pharo-project(a)lists.gforge.inria.fr >>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> >> >> _______________________________________________ >> Pharo-project mailing list >> Pharo-project(a)lists.gforge.inria.fr >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project

Aug. 25, 2010

[Pharo-project] [update 1.2] #12112

by stephane ducasse

- Issue 1899: MethodDictionary improvement. Part two. - Issue 2560: Convenient methods from Grease for Strings. We should get more of them. We need cool libraries. - Issue 2857: improve String to Number conversion. readFrom: now raises an error instead of silently returning 0. Thanks Guillermo Polito. Stef

Aug. 25, 2010

Re: [Pharo-project] 'foo' asTime

by Nicolas Cellier

2010/8/25 StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>: > Hi nicolas > > If I understand you correctly we are in sync. > Yes readFrom: should read or fails raising an Error > and we should use Integer readFrom: 'foo' ifFail: [the default value that the client knows that he wants] > > Now we integrated your number parsers so this is strange that the behavior is not like you mention > did you make them backwards compatible? > > So I would give a try to get readFrom: clean. > Johan please give a try > > Stef > Yes, all the infrastructure is there, just change the top message to be awkward-uncompatible ;) like Guillermo is suggesting. See also my other suggestion: implement #readFrom:ifFail: in every class instead of #readFrom: and let readFrom default implementation to just be ^self readFrom: aStream ifFail: [self error: 'invalid format'] One question I'm not sure about is whether we should distinguish 2 API's: - one for reading a single object and bark on extra-characters - IMO, this would be the correct Behaviour of #readFromString: - one for reading an object in a longer sequence of objects (just keep the stream positionned after last character read) - this would be readFrom: aStream Nicolas > > >> In squeak, (Integer readFromString: 'foo') ->Error >> >> Use: >> - Integer readFrom: 'foo' ifFail: [0], tp get backward compatibility, >> - (Integer readFrom: 'foo' ifFail: []), to get nil >> >> Though it is possible, I dislike anwsering nil, because it would mean >> a bunch of #readFrom: send should be protected by #ifNil: Blocks... >> 1) That's nonsense, readFrom:ifFail: already does the work. >> 2) you cripple the code with Error conditions and end up with >> unreadable C-looking like code >> Â (3 lines of Error condition crap for 1 line of underlying algorithm >> at every function call) >> 3) Exception handling can avoid long chains of ifFail: / ifNil: tests >> >> But that conversation already took place many times... >> >> I'd like the readFrom:ifFail: form to be generalized to other objects, >> with default behaviour raising an Error. What do you think ? >> >> Nicolas >> >> 2010/8/24 Johan Brichau <johan(a)inceptive.be>: >>> >>> On 24 Aug 2010, at 15:19, StÃ©phane Ducasse wrote: >>> >>>> I thought that readFromString: was raising an error and that guessNumber* was returning zero >>> >>> I thought that too. I even have application code that shows that this used to return nil in some version of Pharo... >>> But: >>> >>> 'foo' asInteger = nil >>> Integer readFromString: 'foo' = 0 >>> 'foo' asNumber -> Error >>> >>> aargh :-( >>> >>> disclaimer: currently testing this in pharo1.1 >>> >>> Johan >>> _______________________________________________ >>> Pharo-project mailing list >>> Pharo-project(a)lists.gforge.inria.fr >>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >>> >> >> _______________________________________________ >> Pharo-project mailing list >> Pharo-project(a)lists.gforge.inria.fr >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >

Aug. 25, 2010

[Pharo-project] Really funny bug... :(

by stephane ducasse

Hi guys I was integrated the methodDictionary enh of levente. And after I integrated the addition of some methods into String. Then it seems that I got all the packages extending String dirty. I checked the changes and nothing special. The changed methods are not logged in the changeSorter. So may be the dictionary got rehashed, changed and all the methods went to get "changed". Strange. Stef

Aug. 25, 2010

Re: [Pharo-project] String to Number conversion

by Schwab,Wilhelm K

Stef, I thought about this a little more: perhaps the conversion got started for eToys? I could see somebody adding that to make them work; the Dolphin guy in me then screams Value-Adapter!!! :) A quick look at my image does not reveal an aspect value adapter and a converter; I thought I had built them. I probably did and lost track of them due to my (for far too long) woefully incomplete understanding of package info and MC. The basic idea is that a suitable object can be "clipped" between a thing that understands #value and #value: and a consumer. With some artful use, a text editor can then be used, for example, to edit a floating point aspect of something else. Having real closures vs. Smalltalk-80 blocks will only make it easier to get it right. I will look for an existing implementation of mine or put it in the queue; we can't not have these things. Bill ________________________________________ From: pharo-project-bounces(a)lists.gforge.inria.fr [pharo-project-bounces(a)lists.gforge.inria.fr] On Behalf Of StÃ©phane Ducasse [stephane.ducasse(a)inria.fr] Sent: Wednesday, August 25, 2010 12:44 PM To: Pharo-project(a)lists.gforge.inria.fr Subject: Re: [Pharo-project] String to Number conversion +1 Stef On Aug 25, 2010, at 12:53 PM, Schwab,Wilhelm K wrote: > While I'm on rant, what happened to the good old day when men were men and 2+'2' was not 4? I *still* have bugs in my R data frame code because of that nonsense - just tell me I blew it, please?? Ceorsing integers to floats to make things like 2+Float pi is a good thing, converting strings to numbers is coddling that ultimately backfires. > > Bill > > > > > ________________________________________ > From: pharo-project-bounces(a)lists.gforge.inria.fr [pharo-project-bounces(a)lists.gforge.inria.fr] On Behalf Of Schwab,Wilhelm K [bschwab(a)anest.ufl.edu] > Sent: Wednesday, August 25, 2010 5:01 AM > To: Pharo-project(a)lists.gforge.inria.fr > Subject: Re: [Pharo-project] String to Number conversion > > Squeak has a long tradition of silent failures of all types (in the image and the vm), and IMNSHO, it is a **really** bad idea with terrible consequences and needs to be fixed. Default actions that return nil merely push problems down stream to a point where there is no context to figure out what went wrong. I think much of this goes back to the late 70's and early 80's, before structured exception handling, and has never been modernized. Dolphin, which started life in the mid 90's, is built from the ground up to do these things correctly. Once one learns that the exceptions are indeed helping to make things work reliably, it is hard to imagine making something robust without them. > > Exceptions can be expensive, both to set up handlers, and even more so when exceptions are thrown. You have identified the answer, which is to provide #readFrom:ifFail: (or #readFrom:onError: - whatever you want to call it) that evaluates a block when things go wrong, which allows one to bypass the overhead, much like #at:ifAbsent:; if error and remedy are near by, it is easy to do and skips the overhead. For the lazy<g>, or simply for frameworks that can/should use exceptions to handle exceptional conditions (big separation between the problem and anything that knows how to cope with it), #readFrom: (without the block) does the robust/correct thing, and raises an exception. As you no doubt know, it can (often should) be written in terms of #readFrom:ifFail: with the block raising the exception. > > Things will break for a while, but I hesitate to think how much stuff is just plain broken and we never notice it because things answer nil and/or ignore error conditions. The industry tried to formalize such head-in-the-sand-hope-it-goes-away design under the fancy name "defensive programming." It remains a useful approach when used sparingly to keep critical systems running, but it generally failed under its own lack of merit. It was popularized as a way to cope with the dreaded UAEs of 16 bit Windows, which was in turn due to the lack of exception handling and ensured execution in the GUI, which lead to incomplete cleanup, memory leaks, and all kinds of crashes. > > YES. PLEASE DO THIS. **GREAT** IDEA. You might take a look at > > http://www.squeaksource.com/PharoInbox/DolphinCompatibility-Streams-BillSch… > > for what I consider to be very much related changes to stream I/O. Since it quickly became obvious to me that #next and #next: were not going to change any time soon, I simply stopped using them myself; instead I write code using #nextOne, #nextMany:, and #nextAvailable:. You will also find methods such as #nextDWORD to help with binary file formats, device interfacing, etc . > > It is a work in progress, but the idea is to have read streams bark when they run out of data, unless (#nextAvailable:) specifically authorized to truncate. I also have some text converters modeled after Dolphin's framework. I don't think I have released those yet, but plan to do so eventually. Because of the problem you have identified, I have added some tests (and throw exceptions when they fail) for whether the stream is or is not at the end or read an expected number of types, etc. > > Thanks for working on this! > > Bill > > > > ________________________________________ > From: pharo-project-bounces(a)lists.gforge.inria.fr [pharo-project-bounces(a)lists.gforge.inria.fr] On Behalf Of Guillermo Polito [guillermopolito(a)gmail.com] > Sent: Tuesday, August 24, 2010 4:33 PM > To: Pharo-project(a)lists.gforge.inria.fr > Subject: [Pharo-project] String to Number conversion > > http://code.google.com/p/pharo/issues/detail?id=2857 > > Which will be the impact in the system and other tools to throw an error when the conversion cannot take place? > I think an error must be thrown, but should it be in Pharo 1.2 or in next version? > > On Tue, Aug 24, 2010 at 11:45 AM, Nicolas Cellier <nicolas.cellier.aka.nice(a)gmail.com<mailto:nicolas.cellier.aka.nice@gmail.com>> wrote: > In squeak, (Integer readFromString: 'foo') ->Error > > Use: > - Integer readFrom: 'foo' ifFail: [0], tp get backward compatibility, > - (Integer readFrom: 'foo' ifFail: []), to get nil > > Though it is possible, I dislike anwsering nil, because it would mean > a bunch of #readFrom: send should be protected by #ifNil: Blocks... > 1) That's nonsense, readFrom:ifFail: already does the work. > 2) you cripple the code with Error conditions and end up with > unreadable C-looking like code > (3 lines of Error condition crap for 1 line of underlying algorithm > at every function call) > 3) Exception handling can avoid long chains of ifFail: / ifNil: tests > > But that conversation already took place many times... > > I'd like the readFrom:ifFail: form to be generalized to other objects, > with default behaviour raising an Error. What do you think ? > > Nicolas > > 2010/8/24 Johan Brichau <johan(a)inceptive.be<mailto:johan@inceptive.be>>: >> >> On 24 Aug 2010, at 15:19, StÃ©phane Ducasse wrote: >> >>> I thought that readFromString: was raising an error and that guessNumber* was returning zero >> >> I thought that too. I even have application code that shows that this used to return nil in some version of Pharo... >> But: >> >> 'foo' asInteger = nil >> Integer readFromString: 'foo' = 0 >> 'foo' asNumber -> Error >> >> aargh :-( >> >> disclaimer: currently testing this in pharo1.1 >> >> Johan >> _______________________________________________ >> Pharo-project mailing list >> Pharo-project(a)lists.gforge.inria.fr<mailto:Pharo-project@lists.gforge.inria.fr> >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr<mailto:Pharo-project@lists.gforge.inria.fr> > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project _______________________________________________ Pharo-project mailing list Pharo-project(a)lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project

Aug. 25, 2010