Re: One type for all

[Keith Thompson <kst@cts.com>]

Robert Dewar <robert_dewar@my-deja.com> writes:
[...]
> So thanks, it is indeed the case that Pascal does NOT have
> structural type equivalence, which is what I remembered (any
> other conclusion would have been a big surprise!)

Right.  After I posted the previous article, it occurred to me that
the phrase "same type" might be ambiguous -- for example, that two
similar record type declarations might be considered to create two
names for the same type.  Fortunately, section 6 says:

    If a type representation does not consist only of a type
    identifier, then it represents an entirely new type.

So yes, standard Pascal does not use structural type equivalence, at
least not for record types.  (Though I seem to recall that some
dialects do use structural equivalence.)

-- 
Keith Thompson (The_Other_Keith) kst@cts.com  <http://www.ghoti.net/~kst>
San Diego Supercomputer Center           <*>  <http://www.sdsc.edu/~kst>
One of the great tragedies of ancient history is that Helen of Troy
lived before the invention of the champagne bottle.