[TUHS] Array index history

Johnny Billquist bqt at update.uu.se
Fri Jun 9 08:28:54 AEST 2017


On 2017-06-08 22:17, Dave Horsfall<dave at horsfall.org> wrote:
> 
> Just to diverge from this thread a little, it probably isn't all that
> remarkable that programming languages tend to reflect the hardware for
> which they were designed.
> 
> Thus, for example, we have the C construct:
> 
>      do { ... } while (--i);
> 
> which translated right into the PDP-11's "SOB" instruction (and
> reminiscent of FORTRAN's insistence that DO loops are run at least once
> (there was a CACM article about that once; anyone have a pointer to it?)).
> 
> And of course the afore-mentioned FORTRAN, which really reflects the
> underlying IBM 70x architecture (shudder).

FORTRAN stopped running the loops at least once already with FORTRAN 77. 
The last who insisted on running loops at least once was FORTRAN IV.

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol


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