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Re: How might multiple `entry` points have looked/worked?

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On Thursday December 8 2016 23:57, in comp.lang.c, "luser droog"
<luser.droog@gmail.com> wrote:

> The `entry` keyword. They must have put some thought
> into it to reserve that name for so long. But there
> must also have been insurmountable difficulty in the
> way of getting it right, or else they'd've done it.
> 
> So, how might multiple `entry` points have looked/worked?

There's not a clue as to what the C 'entry' keyword (if it had been
implemented) would have done or how it would have worked. Only Brian
Kernighan or Dennis Ritchie (or, perhaps, S.C. Johnson) could tell you.

> What was the point? 

One might imagine that "the implementors" expected to use "entry" in the same
way that S.I Feldman and P. J. Weinberger of Bell Labs had used it in
their "Portable Fortran 77 Compiler" for Unix. In that Fortran 77
compiler, 'entry' provided an additional, secondary entrypoint for any
Fortran subroutine or function subprogram (their terminology). To quote the
Bell Labs "A Portable Fortran 77 Compiler":
  "Multiple entry points are now legal. Subroutine and function subprograms
   may have additional entry points, declared by an /entry/ statement with an
   optional argument list.
      entry extra(a,b,c)
   Execution begins at the first statement following the /entry/ line. All
   variable declarations must precede all executable statements in the
   procedure. ... If any entry is a character-valued function, then all
   entries must be. "

If that was the intent of the C 'entry' reserved word, then one might imagine
it would permit the C programmer to combine the logic from several similar C
functions into one function with several entrypoints.

> What can it do?

The C 'entry' reserved word? It can do nothing (other than discourage the
programmer from using the token <<entry>> in their code). It was never
implemented as a keyword, never designated a function in the C language.

> Could it be done now?

Of course it could. "Nothing" can always be done.

> Why (not)?  

Isn't it obvious?

-- 
Lew Pitcher
"In Skills, We Trust"
PGP public key available upon request

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How might multiple `entry` points have looked/worked? luser droog <luser.droog@gmail.com> - 2016-12-08 20:57 -0800
  Re: How might multiple `entry` points have looked/worked? Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> - 2016-12-09 07:28 +0100
  Re: How might multiple `entry` points have looked/worked? fir <profesor.fir@gmail.com> - 2016-12-09 00:25 -0800
    Re: How might multiple `entry` points have looked/worked? fir <profesor.fir@gmail.com> - 2016-12-09 00:32 -0800
    Re: How might multiple `entry` points have looked/worked? fir <profesor.fir@gmail.com> - 2016-12-09 00:53 -0800
  Re: How might multiple `entry` points have looked/worked? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-09 13:11 +0000
    Re: How might multiple `entry` points have looked/worked? Noob <root@127.0.0.1> - 2016-12-09 16:36 +0100
      Re: How might multiple `entry` points have looked/worked? Richard Heathfield <rjh@cpax.org.uk> - 2016-12-09 16:00 +0000
      Re: How might multiple `entry` points have looked/worked? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-09 16:18 +0000
  Re: How might multiple `entry` points have looked/worked? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2016-12-09 11:25 -0500
    Re: How might multiple `entry` points have looked/worked? luser droog <luser.droog@gmail.com> - 2016-12-09 15:51 -0800
  Re: How might multiple `entry` points have looked/worked? "James R. Kuyper" <jameskuyper@verizon.net> - 2016-12-09 12:48 -0500
    Re: How might multiple `entry` points have looked/worked? Richard Heathfield <rjh@cpax.org.uk> - 2016-12-09 18:16 +0000
  Re: How might multiple `entry` points have looked/worked? Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-10 07:16 -0800
    Re: How might multiple `entry` points have looked/worked? Noob <root@127.0.0.1> - 2016-12-10 16:58 +0100
      Re: How might multiple `entry` points have looked/worked? Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-14 21:15 -0800

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