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Re: How to type braces for computed gotos

From wclodius@earthlink.net (William Clodius)
Newsgroups comp.compilers
Subject Re: How to type braces for computed gotos
Date 2014-07-21 21:44 -0600
Organization Compilers Central
Message-ID <14-07-054@comp.compilers> (permalink)
References <14-05-013@comp.compilers> <14-07-033@comp.compilers> <14-07-048@comp.compilers>

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Anton Ertl <anton@mips.complang.tuwien.ac.at> wrote:

> I guess this compiler implements the labels-as-values extension of GNU
> C (aka "computed goto", but see the Fortran note below).  The type of
> a label is always void *; static typing fans might prefer a separate
> label type (or a whole type system for labels), but I guess that the
> intersection between static typing fans and the users of this
> extension is very small.  I have used labels-as-values extensively and
> I have not produced errors stemming from confusion between labels and
> other occurences of void *.
>
> BTW, in Fortran this feature is called "assigned goto", and it uses
> integer variables (i.e., not a special type, either) for storing the
> labels (and therefore needs a separate syntax "assign 50 to l" instead
> of just writing "l=50").  Fortran also has a feature called "computed
> goto", but that is closer to a C switch than a GNU C "goto *".

Not quite the rough equivalent of a C switch statement is the Fortran 90
SELECT CASE. A Fortran computed GO TO, as with an assigned GO TO, does
not have a syntactic block associated with it, and can be set up to go
to any label within the current program or sub-program.

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Thread

Best "simple" C Compiler I've ever seen andrewchamberss@gmail.com - 2014-05-04 18:23 -0700
  Re: Best "simple" C Compiler I've ever seen federation2005@netzero.com - 2014-06-30 12:42 -0700
  How to type braces for computed gotos (was: Best "simple" C Compiler I've ever seen) federation2005@netzero.com - 2014-07-18 14:44 -0700
    Re: How to type braces for computed gotos glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-19 02:21 +0000
      Re: How to type braces for computed gotos Ivan Godard <ivan@ootbcomp.com> - 2014-07-18 21:59 -0700
      Re: How to type braces for computed gotos federation2005@netzero.com - 2014-07-21 10:32 -0700
    Re: How to type braces for computed gotos (was: Best "simple" C Compiler I've ever seen) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-21 11:45 +0000
      Re: How to type braces for computed gotos glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-21 16:19 +0000
      Re: How to type braces for computed gotos wclodius@earthlink.net (William Clodius) - 2014-07-21 21:44 -0600
        Re: How to type braces for computed gotos glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-23 00:35 +0000
          Re: How to type braces for computed gotos wclodius@earthlink.net (William Clodius) - 2014-07-22 22:36 -0600
            Re: How to type braces for computed gotos anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-25 22:38 -0400

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