"for" loops in C ...

Steven Ryan smryan at garth.UUCP
Thu Nov 10 07:22:26 AEST 1988


>- just like good ol' array indexing in FORTRAN - array(i).  Well, why
>not?  BCPL made it very obvious that a[i] and i[a] are the same; it

To an optimiser in a language with real arrays, they are not the same.

In such languages, lwb a<=i<=upb a so that the location is constrained
to the region labeled a. This permits optimisers to make assumptions about
whether two memory references can interfere.

>used (uses?) a!i to mean *(a+i).  This works fine even for structure
>access, until you have strong typing.  Guess what BCPL didn't have?  I,
>personally, IMHO, would be happy with a[next] for structure access or
>a.i for array access.  Isn't it all really the same and just a matter

How would you parse that? Fields and subscripts have different syntax,
although the concept are similar, to make context-free parsing possible.
-- 
                                                   -- s m ryan
--------------------------------------------------------------------------------
As loners, Ramdoves are ineffective in making intelligent decisions, but in
groups or wings or squadrons or whatever term is used, they respond with an
esprit de corps, precision, and, above all, a ruthlessness...not hatefulness,
that implies a wide ranging emotional pattern, just a blind, unemotional
devotion to doing the job.....



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