[fpc-pascal] Re: Porting linux to pascal, would it be possible ?

[Prince Riley]

Here is a direct reference from the Wikipedia article I referenced in my
prior post ...

In 1973, Unix was rewritten in the C programming
language<http://en.wikipedia.org/wiki/C_%28programming_language%29>,
contrary to the general notion at the time "that something as complex as an
operating system, which must deal with time-critical events, had to be
written exclusively in assembly
language".[4]<http://en.wikipedia.org/wiki/UNIX#cite_note-Stallings-3>The
migration from assembly
language <http://en.wikipedia.org/wiki/Assembly_Language> to the higher-level
language <http://en.wikipedia.org/wiki/High-level_programming_language> C
resulted in much more
portable<http://en.wikipedia.org/wiki/Software_quality#Portability>software,
requiring only a relatively small amount of machine-dependent code
to be replaced when porting Unix to other computing
platforms<http://en.wikipedia.org/wiki/Platform_%28computing%29>
.

Prince


On Fri, Dec 5, 2008 at 7:57 PM, Prince Riley <wmarketing3 at gmail.com> wrote:

> Hello
>
> I don't mean to start a culture war here, but I think there is a bit of
> overstatement in this post that 'C' is somehow a better language for writing
> an OS in than say Pascal or OP or anything else.
>
> In point of fact, the only 'best' language for any processor is its own
> machine code which is always binary.
> And the first operating system software written was done so in the assembly
> language which is written to use mnemoics
> that when 'assembled' convert directly into the binary machine language on
> a one to one basis.
>
> Now EVERY compiled language, including  C, must be processed from its
> syntactical representation into assembly language or machine code. In fact,
> if you download the GCC complier source code and read it, you'll see  almost
> immediately that it actually a 'language' front-end connected to a
> 'assembler machine code' back end.
>
> When the 'C' language was designed at AT&T it used 'assembler' like
> constructs and syntax because it's author wanted
> to stop writing programs in a language called BCPL..
>
> So aside from a 'historical accident'  that the first AT&T OS ..UNIX.. was
> being written at the same time C was being developed, there is no other
> reason for any program, including an OS, to be written in C. To suggest that
> C is better is rather like suggesting that Spanish is a better language than
> English for writing a novel.
>
> That said, if someone wished to write a modern OS in FP, which has nearly
> every programming construct that 'C' has (ints, doubles, floats, bytes, and
> bits) and you were willing to put in the time to fine tune and modify the FP
> compiler, you could produce a OS in FP that would be every bit as effective
> and perform as well or better as one written in C.  And as far as the
> processor running the OS couldn't tell what language the OS was written in.
>
>
> If anyone wants to convince themselves on this its simple, you'll find
> Ritchie (the creator of the C language) explained these points in the
> preface to his first book on C. There is also a brief mention of this in the
> Wikipedia article on the UNIX operating system. (see the article footnotes)
>
> Prince
>
>
> On Fri, Dec 5, 2008 at 6:59 PM, Guillermo Martínez Jiménez <
> gmjimen at burdjia.com> wrote:
>
>> > Are you sure?
>>
>> Yes, I am.
>>
>> > doesn't older MacOS's versions where written in Object Pascal?
>>
>> Yes, it does, but as I said I think it wasn't the better options.
>>
>> > I think the problem here (again) is not the language, it's the critical
>> mass of users of the language. Using C for Linux was a good bet, not because
>> the language is good (Pascal is way better for me), but because C has a
>> wider user base who can fix/add features.
>>
>> I disagree.  C is better for write operating systems *by definition*:
>> C was created to write UNIX, Pascal was created to learn good
>> programming techniques.  C is low/mid-level language, Pascal is
>> high-level (and Object Pascal is even higher):  OS are the lowest
>> software level.
>>
>> I'm not saying it's impossible:  here you have MacOS and Toro. I'm
>> just saying that _I think_ it isn't the best option.  Of course a
>> better option is to write the kernel in C and Assembler and the
>> utilities in Pascal and Object Pascal.
>>
>> Guillermo "Ñuño" Martínez
>> _______________________________________________
>> fpc-pascal maillist  -  fpc-pascal at lists.freepascal.org
>> http://lists.freepascal.org/mailman/listinfo/fpc-pascal
>>
>
>
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