Re: FORTRAN bug(was Re: C++ vs. Ada -- Is Ada loosing?)

[munnari.oz.au!cs.mu.OZ.AU!munta.cs.mu.OZ.AU!fjh@uunet.uu.net (Fergus Jam es HENDERSON)]

mfeldman@seas.gwu.edu (Michael Feldman) writes:

>You make a good point. Perhaps the modern equivalent of that Fortran
>single-keystroke bug is my favorite bit of C code (and no, I don't
>want to bash C, just point out how common these flukes are):
>
>   int x;
>   ...
>   x = 1;
>   while (x <= 10);
>   { 
>      printf("%d\n", x);
>      x++;
>   }

A good compiler would give a warning that the call to printf was
unreachable code. The only compiler I have available, gcc, unfortunately
doesn't give any such warning. But the Pascal-subset compiler I wrote (as one
of the projects for a 3rd-year subject) gives the following warnings for
the equivalent Pascal code:

warning: variable 'x' is not used after assignment, so assignment has no effect
warning: 'while' statement will cause an infinite loop

>Any similar idiosyncracies in Ada? 

The difference between '<' and '>' is only a single keystroke.
More insidious perhaps is the difference between '<' and '<='.
So it can happen even in Ada. 

However I do agree that Ada syntax is less error-prone than C or Fortran.
This is not because it is verbose but rather because the Ada designers took
this issue into careful consideration. I believe that it would be quite
possible to design a syntax that was concise but that was no more error-prone
than Ada.

-- 
Fergus Henderson             fjh@munta.cs.mu.OZ.AU      
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