Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Thanks On Thu, Apr 12, 2018 at 5:06 PM, Alistair Grant wrote: > On 11 April 2018 at 20:47, Sven Van Caekenberghe wrote: >> >> But there is something wrong with what is returned by Stdio stdin >> > > I've opened >

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

On 11 April 2018 at 20:47, Sven Van Caekenberghe wrote: > > But there is something wrong with what is returned by Stdio stdin > I've opened https://pharo.fogbugz.com/f/cases/21692/StdioStream-incorrectly-delegates-atEnd-and-position-to-file PR in progress. Cheers, Alistair

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

On 12 April 2018 at 10:48, Alistair Grant wrote: > > So I'm going to respectfully disagree and say that I think to raise a > MNU instead of returning nil is wrong, and that changing the Zinc > streams isn't such a big deal. Sorry Sven, this sounds like I'm suggesting that

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Sven, On Thu, Apr 12, 2018 at 09:23:21AM +0200, Sven Van Caekenberghe wrote: > > > > On 12 Apr 2018, at 08:33, Alistair Grant wrote: > > > > ... > > > > In your example you've carefully exited by some other means than > > signalling end-of-file (Ctrl-D). > > > > I don't

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

> On 12 Apr 2018, at 03:15, Eliot Miranda wrote: > > Hi Sven, > > On Wed, Apr 11, 2018 at 1:25 PM, Sven Van Caekenberghe wrote: > > > > On 11 Apr 2018, at 21:44, Stephane Ducasse wrote: > > > > I did not know about the

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

> On 12 Apr 2018, at 04:07, Ben Coman wrote: > > > > On 12 April 2018 at 04:25, Sven Van Caekenberghe wrote: > > > > On 11 Apr 2018, at 21:44, Stephane Ducasse wrote: > > > > I did not know about the NeoConsole. Nice because I

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

> On 12 Apr 2018, at 08:33, Alistair Grant wrote: > > Hi Sven, > > On 11 April 2018 at 20:47, Sven Van Caekenberghe wrote: >> Alistair, >> >>> On 11 Apr 2018, at 19:42, Sven Van Caekenberghe wrote: >>> >>> I will send you some code later

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Sven, On 11 April 2018 at 20:47, Sven Van Caekenberghe wrote: > Alistair, > >> On 11 Apr 2018, at 19:42, Sven Van Caekenberghe wrote: >> >> I will send you some code later on. > > Today I arranged for my NeoConsole code (that normally works over a network >

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

On Wednesday 11 April 2018 10:38 PM, Alistair Grant wrote: StandardFileStream>>readInto:startingAt:count: assumes that primitiveFileRead will always attempt to read count bytes, but it actually only attempts to read 1. StandardFileStream>>#basicNext uses position < readLimit ifFalse: and

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

On 11 April 2018 at 19:42, Nicolas Cellier wrote: > > > 2018-04-11 19:08 GMT+02:00 Alistair Grant : >> >> Hi Sven, >> >> On 11 April 2018 at 18:53, Sven Van Caekenberghe wrote: >> > Something is off (and/or I am getting

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

On 12 April 2018 at 04:25, Sven Van Caekenberghe wrote: > > > > On 11 Apr 2018, at 21:44, Stephane Ducasse > wrote: > > > > I did not know about the NeoConsole. Nice because I wanted to build a > > little REPL for my minilanguage implementation. > > You

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Sven, On Wed, Apr 11, 2018 at 1:25 PM, Sven Van Caekenberghe wrote: > > > > On 11 Apr 2018, at 21:44, Stephane Ducasse > wrote: > > > > I did not know about the NeoConsole. Nice because I wanted to build a > > little REPL for my minilanguage

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

> On 11 Apr 2018, at 21:44, Stephane Ducasse wrote: > > I did not know about the NeoConsole. Nice because I wanted to build a > little REPL for my minilanguage implementation. You are of course welcome to look at it. But it is Pharo specific. I use it to be able to

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

I did not know about the NeoConsole. Nice because I wanted to build a little REPL for my minilanguage implementation. Stef On Wed, Apr 11, 2018 at 8:47 PM, Sven Van Caekenberghe wrote: > Alistair, > >> On 11 Apr 2018, at 19:42, Sven Van Caekenberghe wrote: >> >> I

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

On Wed, Apr 11, 2018 at 5:33 PM, Sven Van Caekenberghe wrote: > I think we have to reset this whole discussion. > > FileStream stdin > > and > > Stdio stdin > > are completely different ! Could you explain the difference because I'm dead tired and got confused :) > > We'll

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

On Wed, Apr 11, 2018 at 12:04 PM, Denis Kudriashov wrote: > Hi Alistair. > > I don't think anybody is annoyed by you. You are doing really good job. And > nice thing that you are super patient to continue :) +10 > > What I try to understand is why blocking atEnd is

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Alistair, > On 11 Apr 2018, at 19:42, Sven Van Caekenberghe wrote: > > I will send you some code later on. Today I arranged for my NeoConsole code (that normally works over a network connection) to work over stdio. Although I am not yet happy with every aspect of the

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

2018-04-11 19:08 GMT+02:00 Alistair Grant : > Hi Sven, > > On 11 April 2018 at 18:53, Sven Van Caekenberghe wrote: > > Something is off (and/or I am getting crazy, probably both). > > > > $ ./pharo --headless Pharo.image eval '(FileStream stdin binary; next:

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hmm, but why does the following work then ? $ ./pharo --headless Pharo.image eval '(FileStream stdin next: 3)' 123 '123' The binary case is an error though, for sure. And Zn character decoding works on binary streams, while the buffering streams read in blocks. And it always comes back to

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Sven, On 11 April 2018 at 18:53, Sven Van Caekenberghe wrote: > Something is off (and/or I am getting crazy, probably both). > > $ ./pharo --headless Pharo.image eval '(FileStream stdin binary; next: 3)' > 123 > #[49] > > ?? > > This should return #[49 50 51] AFAIK. I haven't

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Something is off (and/or I am getting crazy, probably both). $ ./pharo --headless Pharo.image eval '(FileStream stdin binary; next: 3)' 123 #[49] ?? This should return #[49 50 51] AFAIK. > On 11 Apr 2018, at 18:26, Alistair Grant wrote: > > Hi Sven, > > On 11 April

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Sven, On 11 April 2018 at 17:33, Sven Van Caekenberghe wrote: > I think we have to reset this whole discussion. > > FileStream stdin > > and > > Stdio stdin > > are completely different ! > > We'll have to check that first, before talking about the issues raised in > this

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Denis, On 11 April 2018 at 17:16, Denis Kudriashov wrote: > > 2018-04-11 17:02 GMT+02:00 Sven Van Caekenberghe : >> >> >> >> > On 11 Apr 2018, at 16:36, Sven Van Caekenberghe wrote: >> > >> > I can make your example, using the Zn variants,

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

I think we have to reset this whole discussion. FileStream stdin and Stdio stdin are completely different ! We'll have to check that first, before talking about the issues raised in this thread. And BTW these terminal streams are a real pain to test ;-) > On 11 Apr 2018, at 17:20,

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

> On 11 Apr 2018, at 17:16, Denis Kudriashov wrote: > > > 2018-04-11 17:02 GMT+02:00 Sven Van Caekenberghe : > > > > On 11 Apr 2018, at 16:36, Sven Van Caekenberghe wrote: > > > > I can make your example, using the Zn variants, work with

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

2018-04-11 17:02 GMT+02:00 Sven Van Caekenberghe : > > > > On 11 Apr 2018, at 16:36, Sven Van Caekenberghe wrote: > > > > I can make your example, using the Zn variants, work with the following > change: > > > > StdioStream>>#atEnd > > ^ peekBuffer isNil or: [

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

> On 11 Apr 2018, at 16:36, Sven Van Caekenberghe wrote: > > I can make your example, using the Zn variants, work with the following > change: > > StdioStream>>#atEnd > ^ peekBuffer isNil or: [ (peekBuffer := self next) isNil ] Argh, make that atEnd ^ peekBuffer isNil and:

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

I can make your example, using the Zn variants, work with the following change: StdioStream>>#atEnd ^ peekBuffer isNil or: [ (peekBuffer := self next) isNil ] Which is a literal implementation of your statement that you can only know that you are atEnd by reading (and thus waiting/blocking)

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

On 11 April 2018 at 15:11, Sven Van Caekenberghe wrote: > > >> On 11 Apr 2018, at 11:12, Sven Van Caekenberghe wrote: >> >> How does one modify #atEnd to block ? I suppose you are talking about >> StdioStream>>#atEnd ? >> >> ^ self peek isNil >> >> ? > > Still the

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

OS pipes are a similar case. On Pharo, you can run CommandShellTestCase to provide some test coverage for this. Dave On Wed, Apr 11, 2018 at 03:13:35PM +0200, Denis Kudriashov wrote: > Thanks for explanation. > > I think it would be same scenario for socket stream where #atEnd is not >

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Alistair, I must take my part too: I suggested that we could use a pair of getc/ungetc to know if we are atEnd(OfData), but this obviously works well with AsyncFileIO only, else it blocks. For files, this generally isn't a problem (but maybe for network mounted partitions), the latency is

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Thanks for explanation. I think it would be same scenario for socket stream where #atEnd is not blocking. So I agree that it is expected behaviour. The example is general enough to expect it to be working for any given pair of in and out streams. So our streams should support this. 2018-04-11

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

> On 11 Apr 2018, at 11:12, Sven Van Caekenberghe wrote: > > How does one modify #atEnd to block ? I suppose you are talking about > StdioStream>>#atEnd ? > > ^ self peek isNil > > ? Still the same question, how do you implement a blocking #atEnd for stdin ? I have seen your

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Sven & Dennis, On 11 April 2018 at 12:04, Denis Kudriashov wrote: > Hi Alistair. > > I don't think anybody is annoyed by you. You are doing really good job. And > nice thing that you are super patient to continue :) > On 11 April 2018 at 12:13, Sven Van Caekenberghe

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

> On 11 Apr 2018, at 12:04, Denis Kudriashov wrote: > > I don't think anybody is annoyed by you. You are doing really good job. And > nice thing that you are super patient to continue :) Yes, Alistair, you are a top notch open source contributor ! For me, this

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Alistair. I don't think anybody is annoyed by you. You are doing really good job. And nice thing that you are super patient to continue :) What I try to understand is why blocking atEnd is bad? Here is code from VMMaker: [stdin atEnd] whileFalse: [| nextChunk | stdout nextPutAll: 'squeak> ';

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Sven, Oh dear. I feel as though I'm not getting my concerns across at all well, and I'm pushing hard enough that all I'm going to do is make people annoyed. So let me try to restate the issue one last time before answering your questions directly. Pharo & Squeak have unwritten rules about

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

> On 11 Apr 2018, at 10:29, Alistair Grant wrote: > > Hi Denis, > > On 11 April 2018 at 10:02, Denis Kudriashov wrote: >> >> 2018-04-11 8:32 GMT+02:00 Alistair Grant : >>> >> Where is it being said that #next and/or

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Denis, On 11 April 2018 at 10:02, Denis Kudriashov wrote: > > 2018-04-11 8:32 GMT+02:00 Alistair Grant : >> >> >>> Where is it being said that #next and/or #atEnd should be blocking or >> >>> non-blocking ? >> >> >> >> There is existing code that

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

2018-04-11 8:32 GMT+02:00 Alistair Grant : > >>> Where is it being said that #next and/or #atEnd should be blocking or > non-blocking ? > >> > >> There is existing code that assumes that #atEnd is non-blocking and > >> that #next is allowed block. I believe that we should

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Sven, On 10 April 2018 at 23:54, Sven Van Caekenberghe wrote: > Alistair, > > I am replying in-between, please don't take my remarks as being negative, I > just like to straighten things out as clear as possible. No problem. >> On 10 Apr 2018, at 22:14, Alistair Grant

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Alistair, I am replying in-between, please don't take my remarks as being negative, I just like to straighten things out as clear as possible. > On 10 Apr 2018, at 22:14, Alistair Grant wrote: > > Hi Sven, > > On 10 April 2018 at 19:36, Sven Van Caekenberghe

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Sven, On 10 April 2018 at 19:36, Sven Van Caekenberghe wrote: > I have trouble understanding your problem analysis, and how your proposed > solution, would solve it. The discussion started with my proposal to modify the Zinc streams to check the return value of #next for nil

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

I have trouble understanding your problem analysis, and how your proposed solution, would solve it. Where is it being said that #next and/or #atEnd should be blocking or non-blocking ? How is this related to how EOF is signalled ? It seems to me that there are quite a few classes of streams

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

First a quick update: After doing some work on primitiveFileAtEnd, #atEnd now answers correctly for files that don't report their size correctly, e.g. /dev/urandom and /proc/cpuinfo, whether the files are opened directly or redirected through stdin. However determining whether stdin from a

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Thanks for this discussion. On Wed, Apr 4, 2018 at 1:37 PM, Sven Van Caekenberghe wrote: > Alistair, > > First off, thanks for the discussions and your contributions, I really > appreciate them. > > But I want to have a discussion at the high level of the definition and >

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

On Wednesday 04 April 2018 09:07 PM, Sven Van Caekenberghe wrote: Good summary, I agree. Still, what are the semantics of #next - does the caller always have to check for nil ? Do we think this is ugly (as the return value is outside the domain) ? Do we then still need #atEnd ? Senders of

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

On Wed, Apr 4, 2018 at 8:37 AM, Sven Van Caekenberghe wrote: > > > > On 4 Apr 2018, at 17:32, K K Subbu wrote: > > > > On Wednesday 04 April 2018 04:06 PM, Nicolas Cellier wrote: > >>> IIRC, someone said it is implemented as 'remaining size being zero' > >>>

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

> On 4 Apr 2018, at 17:32, K K Subbu wrote: > > On Wednesday 04 April 2018 04:06 PM, Nicolas Cellier wrote: >>> IIRC, someone said it is implemented as 'remaining size being zero' >>> and some virtual unix files like /dev/random are zero sized. >> Currently, for files

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

On Wednesday 04 April 2018 04:06 PM, Nicolas Cellier wrote: IIRC, someone said it is implemented as 'remaining size being zero' and some virtual unix files like /dev/random are zero sized. Currently, for files other than sdio (stdout, stderr, stdin) it is effectively defined as: atEnd :=

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Alistair, First off, thanks for the discussions and your contributions, I really appreciate them. But I want to have a discussion at the high level of the definition and semantics of the stream API in Pharo. > On 4 Apr 2018, at 13:20, Alistair Grant wrote: > > On 4

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

On 4 April 2018 at 12:56, Sven Van Caekenberghe wrote: > Playing a bit devil's advocate, the idea is that, in general, > > [ stream atEnd] whileFalse: [ stream next. "..." ]. > > is no longer allowed ? It hasn't been allowed "forever" [1]. It's just been misused for almost as

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Playing a bit devil's advocate, the idea is that, in general, [ stream atEnd] whileFalse: [ stream next. "..." ]. is no longer allowed ? And you want to replace it with [ stream next ifNil: [ false ] ifNotNil: [ :x | "..." true ] whileTrue. That is a pretty big change, no ? I think/feel like

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Nicolas, On 4 April 2018 at 12:36, Nicolas Cellier wrote: > > > 2018-04-04 12:18 GMT+02:00 Alistair Grant : >> >> Hi Sven, >> >> On Wed, Apr 04, 2018 at 11:32:02AM +0200, Sven Van Caekenberghe wrote: >> > Somehow, somewhere there was

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

2018-04-04 12:18 GMT+02:00 Alistair Grant : > Hi Sven, > > On Wed, Apr 04, 2018 at 11:32:02AM +0200, Sven Van Caekenberghe wrote: > > Somehow, somewhere there was a change to the implementation of the > > primitive called by some streams' #atEnd. > > That's a proposed

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Sven, On Wed, Apr 04, 2018 at 11:32:02AM +0200, Sven Van Caekenberghe wrote: > Somehow, somewhere there was a change to the implementation of the > primitive called by some streams' #atEnd. That's a proposed change by me, but it hasn't been integrated yet. So the discussion below should

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi. #next returning nil is definitely looks bad because we will always have case when nil value will not means the end: #(1 nil 2) readSteam next; next; atEnd But I understand that in many cases analysing #next for nil is much more suitable than #atEnd. I am sure that it can be always avoided

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

> On 4 Apr 2018, at 11:38, Nicolas Cellier > wrote: > > Hi Sven, > See also discussion at > https://github.com/OpenSmalltalk/opensmalltalk-vm/pull/232 Thanks Nicolas, I had already seen parts of it. Now, I still want image level changes to be based on

Re: [Pharo-dev] Changed #atEnd primitive - #atEnd vs #next returning nil

Hi Sven, See also discussion at https://github.com/OpenSmalltalk/opensmalltalk-vm/pull/232 2018-04-04 11:32 GMT+02:00 Sven Van Caekenberghe : > Somehow, somewhere there was a change to the implementation of the > primitive called by some streams' #atEnd. > > IIRC, someone said it