Re: just for fun: pop quiz

[Mark Wieder]

Jerry Jensen  writes:

> >> On 2/3/13 3:08 PM, Mark Wieder wrote:
> > Yeah, interesting point. I'm not sure what EOF means in that case
> > either. Is that "I received an EOF char from the port"?
> 
> I don't think EOF is meaningful with a serial driver. The closest character is
Ctrl-D, EOT, end of transmission.

Thanks. Yes, I meant EOT. If EOF for a file stream means you've gotten to the
end then possibly EOF for a serial stream could mean you've received an EOT 
char.

-- 
 Mark Wieder
 mwie...@ahsoftware.net





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Re: just for fun: pop quiz

[Jerry Jensen]

On Feb 3, 2013, at 2:49 PM, Mark Wieder  wrote:

> Jacque-
> 
> Sunday, February 3, 2013, 1:51:24 PM, you wrote:
> 
>> On 2/3/13 3:08 PM, Mark Wieder wrote:
>>> Jacque-
>>> 
>>> Sunday, February 3, 2013, 12:40:43 PM, you wrote:
>>> 
 In the case of sockets and drivers it is possible to read without error
 but not receive all the data due to communication issues. In that case
 you'd want to know if the read had paused or had really finished.
>>> 
>>> I was about to post the same, but then Bob would be on my case
>>> instead , so I'm glad you beat me to it. I'd be happier if the read
>>> command had been written to return the number of characters read, in
>>> which case 0 or -1 would be an error, but we're stuck with what we've
>>> got.
>>> 
> 
>> If you're reading a serial port, you don't always know how many 
>> characters to expect. I'm not sure if that's still the same thing though.
> 
> Yeah, interesting point. I'm not sure what EOF means in that case
> either. Is that "I received an EOF char from the port"?

I don't think EOF is meaningful with a serial driver. The closest character is 
Ctrl-D, EOT, end of transmission.

I've always had to use 
read from driver tPort until empty in tTimeout milliseconds
and put that in a timed repeating loop, buffering until a "real" return char 
comes in.
.Jerry


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Re: just for fun: pop quiz

[Mark Wieder]

Jacque-

Sunday, February 3, 2013, 1:51:24 PM, you wrote:

> On 2/3/13 3:08 PM, Mark Wieder wrote:
>> Jacque-
>>
>> Sunday, February 3, 2013, 12:40:43 PM, you wrote:
>>
>>> In the case of sockets and drivers it is possible to read without error
>>> but not receive all the data due to communication issues. In that case
>>> you'd want to know if the read had paused or had really finished.
>>
>> I was about to post the same, but then Bob would be on my case
>> instead , so I'm glad you beat me to it. I'd be happier if the read
>> command had been written to return the number of characters read, in
>> which case 0 or -1 would be an error, but we're stuck with what we've
>> got.
>>

> If you're reading a serial port, you don't always know how many 
> characters to expect. I'm not sure if that's still the same thing though.

Yeah, interesting point. I'm not sure what EOF means in that case
either. Is that "I received an EOF char from the port"?

-- 
-Mark Wieder
 mwie...@ahsoftware.net


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Re: just for fun: pop quiz

[J. Landman Gay]

On 2/3/13 3:08 PM, Mark Wieder wrote:

Jacque-

Sunday, February 3, 2013, 12:40:43 PM, you wrote:


In the case of sockets and drivers it is possible to read without error
but not receive all the data due to communication issues. In that case
you'd want to know if the read had paused or had really finished.


I was about to post the same, but then Bob would be on my case
instead , so I'm glad you beat me to it. I'd be happier if the read
command had been written to return the number of characters read, in
which case 0 or -1 would be an error, but we're stuck with what we've
got.



If you're reading a serial port, you don't always know how many 
characters to expect. I'm not sure if that's still the same thing though.


--
Jacqueline Landman Gay | jac...@hyperactivesw.com
HyperActive Software   | http://www.hyperactivesw.com

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Re: just for fun: pop quiz

[Mark Wieder]

Jacque-

Sunday, February 3, 2013, 12:40:43 PM, you wrote:

> In the case of sockets and drivers it is possible to read without error
> but not receive all the data due to communication issues. In that case
> you'd want to know if the read had paused or had really finished.

I was about to post the same, but then Bob would be on my case
instead , so I'm glad you beat me to it. I'd be happier if the read
command had been written to return the number of characters read, in
which case 0 or -1 would be an error, but we're stuck with what we've
got.

-- 
-Mark Wieder
 mwie...@ahsoftware.net


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Re: just for fun: pop quiz

[Robert Sneidar]

Once again, Jacque puts the kibosh on our "it's a bug!" session by injecting 
facts!  You can't have any fun around here anymore. ;-)

Bob


On Feb 3, 2013, at 12:40 PM, J. Landman Gay wrote:

> On 2/3/13 1:08 PM, Richard Gaskin wrote:
> 
>> Can you think of a circumstance in which you've already specified to
>> read until EOF, and the command executes flawlessly just as you've asked
>> it to, yet you still need to be notified that it reached EOF?
> 
> The "read from file" command is a subset of the generic "read" command which 
> also includes reading from sockets and drivers (and by extension, reading 
> from servers.) They all have the same syntax, and in the MC dictionary 
> there's only one listing for them all. Because they are the same command 
> internally, they all share the same values in the result.
> 
> In the case of sockets and drivers it is possible to read without error but 
> not receive all the data due to communication issues. In that case you'd want 
> to know if the read had paused or had really finished.
> 
> -- 
> Jacqueline Landman Gay

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Re: just for fun: pop quiz

[J. Landman Gay]

On 2/3/13 1:08 PM, Richard Gaskin wrote:


Can you think of a circumstance in which you've already specified to
read until EOF, and the command executes flawlessly just as you've asked
it to, yet you still need to be notified that it reached EOF?


The "read from file" command is a subset of the generic "read" command 
which also includes reading from sockets and drivers (and by extension, 
reading from servers.) They all have the same syntax, and in the MC 
dictionary there's only one listing for them all. Because they are the 
same command internally, they all share the same values in the result.


In the case of sockets and drivers it is possible to read without error 
but not receive all the data due to communication issues. In that case 
you'd want to know if the read had paused or had really finished.


--
Jacqueline Landman Gay | jac...@hyperactivesw.com
HyperActive Software   | http://www.hyperactivesw.com

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Re: just for fun: pop quiz

[Peter Haworth]

I ran into this a few weeks ago when I was having problems reading a file.
 Turned out it was because I should have been doing a binary read, but
seeing EOF in the result made me think I'd run into some sort of error like
an unexpected EOF or something - wasted a couple of hours trying to track
that down.

On Sun, Feb 3, 2013 at 11:08 AM, Richard Gaskin
wrote:

> It's been around so long that they're not likely to change it, so I won't
> be littering the RQCC with yet another unactionable request.
>
> Still, does seem odd.
>
> Can you think of a circumstance in which you've already specified to read
> until EOF, and the command executes flawlessly just as you've asked it to,
> yet you still need to be notified that it reached EOF?
>



Pete
lcSQL Software 
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Re: just for fun: pop quiz

[Robert Sneidar]

I think one of my guesses would have actually made more sense. Have the result 
return the number of characters read. That way you could check for zero in the 
result, and if not, you have the size of your chunk ready to go. But EOF in the 
result is surprising. It's hard to imagine the developer logic that drove them 
to this conclusion.

Bob


On Feb 3, 2013, at 11:08 AM, Richard Gaskin wrote:

> Jerry Jensen wrote:
> 
> >>> On 03/02/2013, at 11:36 AM, Richard Gaskin wrote:
> >>>
>  Without looking in the Dictionary, what would you expect the value
>  of tResult to be after successful execution of:
> 
>  open file tValidFilePath for read
>  read from file tValidFilePath until EOF
>  put the result into tResult
>  close file tValidFilePath
> 
> 
> >> On 03/02/2013, at 11:38 AM, Monte Goulding wrote:
> >>
> >>> empty?
> >>>
> > On Feb 2, 2013, at 4:39 PM, Monte Goulding wrote:
> >
> >> :-(
> >>
> > Me too. ;-(
> >
> 
> Curious, isn't it?
> 
> In my informal survey among people I've talked with the results were the same 
> as here, with nearly everyone guessing that a read command which executes 
> without error would have empty in "the result".
> 
> Instead, in the case of using specifically "...until EOF" or "...until end", 
> the result contains "eof".
> 
> This turns out to be documented (down in the fine print toward the bottom of 
> the Dictionary entry for "read from file", but not above in the section that 
> describes what "EOF" does), yet it's such a departure from the rest of the 
> language that I was tempted to flag it as a bug.
> 
> It's been around so long that they're not likely to change it, so I won't be 
> littering the RQCC with yet another unactionable request.
> 
> Still, does seem odd.
> 
> Can you think of a circumstance in which you've already specified to read 
> until EOF, and the command executes flawlessly just as you've asked it to, 
> yet you still need to be notified that it reached EOF?
> 
> --
> Richard Gaskin
> Fourth World
> LiveCode training and consulting: http://www.fourthworld.com
> Webzine for LiveCode developers: http://www.LiveCodeJournal.com
> Follow me on Twitter:  http://twitter.com/FourthWorldSys
> 
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Re: just for fun: pop quiz

[Monte Goulding]

On 04/02/2013, at 6:08 AM, Richard Gaskin  wrote:

> Can you think of a circumstance in which you've already specified to read 
> until EOF, and the command executes flawlessly just as you've asked it to, 
> yet you still need to be notified that it reached EOF?

No

--
Monte Goulding

M E R Goulding - software development services
mergExt - There's an external for that!





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Re: just for fun: pop quiz

[Richard Gaskin]

Jerry Jensen wrote:

>>> On 03/02/2013, at 11:36 AM, Richard Gaskin wrote:
>>>
 Without looking in the Dictionary, what would you expect the value
 of tResult to be after successful execution of:

 open file tValidFilePath for read
 read from file tValidFilePath until EOF
 put the result into tResult
 close file tValidFilePath


>> On 03/02/2013, at 11:38 AM, Monte Goulding wrote:
>>
>>> empty?
>>>
> On Feb 2, 2013, at 4:39 PM, Monte Goulding wrote:
>
>> :-(
>>
> Me too. ;-(
>

Curious, isn't it?

In my informal survey among people I've talked with the results were the 
same as here, with nearly everyone guessing that a read command which 
executes without error would have empty in "the result".


Instead, in the case of using specifically "...until EOF" or "...until 
end", the result contains "eof".


This turns out to be documented (down in the fine print toward the 
bottom of the Dictionary entry for "read from file", but not above in 
the section that describes what "EOF" does), yet it's such a departure 
from the rest of the language that I was tempted to flag it as a bug.


It's been around so long that they're not likely to change it, so I 
won't be littering the RQCC with yet another unactionable request.


Still, does seem odd.

Can you think of a circumstance in which you've already specified to 
read until EOF, and the command executes flawlessly just as you've asked 
it to, yet you still need to be notified that it reached EOF?


--
 Richard Gaskin
 Fourth World
 LiveCode training and consulting: http://www.fourthworld.com
 Webzine for LiveCode developers: http://www.LiveCodeJournal.com
 Follow me on Twitter:  http://twitter.com/FourthWorldSys

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Re: just for fun: pop quiz

[Dave Cragg]

I had a vague memory of this and checked in an old script and found the 
following:

read from file laFile[pUrl] for 4096
if the result <> empty and the result <> "eof" then
...


Dave

On 3 Feb 2013, at 00:36, Richard Gaskin  wrote:

> Without looking in the Dictionary, what would you expect the value of tResult 
> to be after successful execution of:
> 
> open file tValidFilePath for read
> read from file tValidFilePath until EOF
> put the result into tResult
> close file tValidFilePath
> 
> 
> --
> Richard Gaskin
> Fourth World
> LiveCode training and consulting: http://www.fourthworld.com
> Webzine for LiveCode developers: http://www.LiveCodeJournal.com
> Follow me on Twitter:  http://twitter.com/FourthWorldSys
> 
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Re: just for fun: pop quiz

[Robert Sneidar]

Wait... the number of characters read?

On Feb 2, 2013, at 4:36 PM, Richard Gaskin wrote:

> Without looking in the Dictionary, what would you expect the value of tResult 
> to be after successful execution of:
> 
> open file tValidFilePath for read
> read from file tValidFilePath until EOF
> put the result into tResult
> close file tValidFilePath


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Re: just for fun: pop quiz

[Robert Sneidar]

empty

On Feb 2, 2013, at 4:36 PM, Richard Gaskin wrote:

> Without looking in the Dictionary, what would you expect the value of tResult 
> to be after successful execution of:
> 
> open file tValidFilePath for read
> read from file tValidFilePath until EOF
> put the result into tResult
> close file tValidFilePath
> 
> 
> --
> Richard Gaskin
> Fourth World
> LiveCode training and consulting: http://www.fourthworld.com
> Webzine for LiveCode developers: http://www.LiveCodeJournal.com
> Follow me on Twitter:  http://twitter.com/FourthWorldSys
> 
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Re: just for fun: pop quiz

[Mark Schonewille]

EOF

--
Best regards,

Mark Schonewille

Economy-x-Talk Consulting and Software Engineering
Homepage: http://economy-x-talk.com
Twitter: http://twitter.com/xtalkprogrammer
KvK: 50277553

Use Color Converter to convert CMYK, RGB, RAL, XYZ, H.Lab and other colour 
spaces. http://www.color-converter.com

We have time for new software development projects. Contact me for a quote.

On 14 January, we suffered severe server problems. If you tried to send an 
e-mail between 13 and 18 January and didn't get a reply, please try again.

On 2/3/2013 01:36, Richard Gaskin wrote:
Without looking in the Dictionary, what would you expect the value of 
tResult to be after successful execution of:


open file tValidFilePath for read
read from file tValidFilePath until EOF
put the result into tResult
close file tValidFilePath



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Re: just for fun: pop quiz

[Jerry Jensen]

Me too. ;-(

On Feb 2, 2013, at 4:39 PM, Monte Goulding  wrote:

> :-(
> 
> On 03/02/2013, at 11:38 AM, Monte Goulding  
> wrote:
> 
>> empty?
>> 
>> On 03/02/2013, at 11:36 AM, Richard Gaskin  
>> wrote:
>> 
>>> Without looking in the Dictionary, what would you expect the value of 
>>> tResult to be after successful execution of:
>>> 
>>> open file tValidFilePath for read
>>> read from file tValidFilePath until EOF
>>> put the result into tResult
>>> close file tValidFilePath
>>> 
>>> 
>>> --
>>> Richard Gaskin
>>> Fourth World
>>> LiveCode training and consulting: http://www.fourthworld.com
>>> Webzine for LiveCode developers: http://www.LiveCodeJournal.com
>>> Follow me on Twitter:  http://twitter.com/FourthWorldSys
>>> 
>>> ___
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>> 
>> --
>> Monte Goulding
>> 
>> M E R Goulding - software development services
>> mergExt - There's an external for that!
>> 
>> 
>> 
>> 
>> 
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> 
> --
> Monte Goulding
> 
> M E R Goulding - software development services
> mergExt - There's an external for that!
> 
> 
> 
> 
> 
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Re: just for fun: pop quiz

[Jerry Jensen]

Me too. empty?
.Jerry

On Feb 2, 2013, at 4:38 PM, Monte Goulding  wrote:

> empty?
> 
> On 03/02/2013, at 11:36 AM, Richard Gaskin  wrote:
> 
>> Without looking in the Dictionary, what would you expect the value of 
>> tResult to be after successful execution of:
>> 
>> open file tValidFilePath for read
>> read from file tValidFilePath until EOF
>> put the result into tResult
>> close file tValidFilePath
>> 
>> 
>> --
>> Richard Gaskin
>> Fourth World
>> LiveCode training and consulting: http://www.fourthworld.com
>> Webzine for LiveCode developers: http://www.LiveCodeJournal.com
>> Follow me on Twitter:  http://twitter.com/FourthWorldSys
>> 
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> 
> --
> Monte Goulding
> 
> M E R Goulding - software development services
> mergExt - There's an external for that!
> 
> 
> 
> 
> 
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Re: just for fun: pop quiz

[Monte Goulding]

:-(

On 03/02/2013, at 11:38 AM, Monte Goulding  wrote:

> empty?
> 
> On 03/02/2013, at 11:36 AM, Richard Gaskin  wrote:
> 
>> Without looking in the Dictionary, what would you expect the value of 
>> tResult to be after successful execution of:
>> 
>> open file tValidFilePath for read
>> read from file tValidFilePath until EOF
>> put the result into tResult
>> close file tValidFilePath
>> 
>> 
>> --
>> Richard Gaskin
>> Fourth World
>> LiveCode training and consulting: http://www.fourthworld.com
>> Webzine for LiveCode developers: http://www.LiveCodeJournal.com
>> Follow me on Twitter:  http://twitter.com/FourthWorldSys
>> 
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> 
> --
> Monte Goulding
> 
> M E R Goulding - software development services
> mergExt - There's an external for that!
> 
> 
> 
> 
> 
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--
Monte Goulding

M E R Goulding - software development services
mergExt - There's an external for that!





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Re: just for fun: pop quiz

[Monte Goulding]

empty?

On 03/02/2013, at 11:36 AM, Richard Gaskin  wrote:

> Without looking in the Dictionary, what would you expect the value of tResult 
> to be after successful execution of:
> 
> open file tValidFilePath for read
> read from file tValidFilePath until EOF
> put the result into tResult
> close file tValidFilePath
> 
> 
> --
> Richard Gaskin
> Fourth World
> LiveCode training and consulting: http://www.fourthworld.com
> Webzine for LiveCode developers: http://www.LiveCodeJournal.com
> Follow me on Twitter:  http://twitter.com/FourthWorldSys
> 
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--
Monte Goulding

M E R Goulding - software development services
mergExt - There's an external for that!





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