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Re: Reading command line in Pascal

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On 2021-04-26 08:33, David Brown wrote:
> On 26/04/2021 07:50, Dmitry A. Kazakov wrote:
>> On 2021-04-25 17:52, David Brown wrote:
>>> On 25/04/2021 16:33, Peter wrote:
>>>> Öö Tiib wrote:
>>>>> On Sunday, 25 April 2021 at 15:47:04 UTC+3, Peter wrote:
>>>>>> How, in standard Pascal (ISO/IEC 7185:1990), does one read the
>>>>>> command line?
>>>>>
>>>>> One does not as that standard does not have concept of command line.
>>>>
>>>> Yet another example of the language's silliness!
>>>
>>> It is not an "example of silliness".  It is simply not something covered
>>> in the standard, because different Pascal implementations need
>>> significantly different ways of getting command line information (and
>>> there are plenty of Pascal implementations for which "command line"
>>> doesn't even make sense).  A language standard is never intended to
>>> cover everything about particular implementations, or cover everything
>>> that is needed for all coding in the language.
>>
>> That would be a great SILLINESS, as the language must be capable of
>> abstraction an implementation.
>>
>> I do not remember Pascal well, but I think it was not that silly. (Maybe
>> the original Wirth's one was)
>>
>> Thus it is rather a lesser kind of silliness: not to provide a standard
>> library to access the program environment.
>>
> 
> Again, this is confusing language standards and language implementation.

To clarify:

#1. A language design concept of having modules with a defined interface.

IF the language has modules THEN the client is dependent on the module 
specification only and the concrete implementation of becomes irrelevant.

#2. Provided #1 the language standard library can contain a module to 
access the process environment.

Not having #1 is a great silliness. Not having #2 is a lesser silliness.

>   And it is dependent on the language, its aims, and its portability.
> Based on my memory of the history, Pascal was designed to be a language
> that was useful, but easy to learn - which meant keeping it small.  It
> was intended that Pascal implementations could be made on a very wide
> variety of systems - but not that Pascal programs should be portable
> between such systems.  Parts of Pascal /code/ could be portable, but it
> was more important that the knowledge and understanding was portable.

That would not preclude either #1 or #2.

I think you conflate code portability with language completeness. 
Wirth's Pascal was greatly portable, but very incomplete. C was 
extremely non-portable, but complete, at least under UNIX.

Pascal incompleteness led to countless substandard implementations 
stuffing the holes. Programs relying on substandard extensions weren't 
non-portable, they were no Pascal.

> Compare this to C, where the intention was that real programs could be
> written in C and compiled directly on a range of systems (as well as
> supporting system-specific programs).  Thus the C standard had to cover
> a good deal more than the Pascal standard.

C failed miserably on both.

> Or at a greater extreme, Java defines things in far more detail with the
> aim of "right once, run everywhere" - meaning it is only useable on a
> smaller subset of systems, but programs are more portable.

Java moved implementation down to the byte code, a very crude approach, 
they tried to correct it later.

> There is no question of "silliness" here - it's just a matter of the
> level of detail that you specify in the standard, and what you leave up
> to particular implementations.

It is not a level of detail, it is functionality (access to the 
environment) provided or not.

A detail would be providing individual command line arguments, but not 
the whole command line [easy under Windows, problematic under UNIX].

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de

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Thread

Reading command line in Pascal Peter <peterxpercival@hotmail.com> - 2021-04-25 13:47 +0100
  Re: Reading command line in Pascal Öö Tiib <ootiib@hot.ee> - 2021-04-25 07:23 -0700
    Re: Reading command line in Pascal Peter <peterxpercival@hotmail.com> - 2021-04-25 15:33 +0100
      Re: Reading command line in Pascal David Brown <david.brown@hesbynett.no> - 2021-04-25 17:52 +0200
        Re: Reading command line in Pascal "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2021-04-26 07:50 +0200
          Re: Reading command line in Pascal David Brown <david.brown@hesbynett.no> - 2021-04-26 08:33 +0200
            Re: Reading command line in Pascal "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2021-04-26 10:21 +0200
              Re: Reading command line in Pascal David Brown <david.brown@hesbynett.no> - 2021-04-26 10:46 +0200
            Re: Reading command line in Pascal Peter <peterxpercival@hotmail.com> - 2021-04-29 17:54 +0100
          Re: Reading command line in Pascal Peter <peterxpercival@hotmail.com> - 2021-04-29 17:52 +0100
            Re: Reading command line in Pascal Peter <peterxpercival@hotmail.com> - 2021-04-29 18:44 +0100
        Re: Reading command line in Pascal Peter <peterxpercival@hotmail.com> - 2021-04-29 17:55 +0100
          Re: Reading command line in Pascal "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com> - 2021-05-05 20:20 +0200
            Re: Reading command line in Pascal Melzzzzz <Melzzzzz@zzzzz.com> - 2021-05-06 08:46 +0000
              Re: Reading command line in Pascal "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2021-05-06 11:55 +0200
                Re: Reading command line in Pascal Melzzzzz <Melzzzzz@zzzzz.com> - 2021-05-06 10:06 +0000
                Re: Reading command line in Pascal An iM <uavyuayve@hotmail.com> - 2021-08-27 11:27 -0700

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