Bug in library report

[Malcolm Wallace]

Alastair Reid <alastair@reid-consulting-uk.ltd.uk> writes:

> > [...] (How do these bugs last so long?)
> 
> None of the compilers actually use the report Prelude/libraries.

Not entirely true.  A large chunk of the nhc98 (and hat) libraries
is copied directly from the Report.  The real problem (maybe this
is what you meant), is that there is no comprehensive test suite
for conformance.  We make do with bits and pieces, but until someone
actually uses the buggy part of a library and complains, we have no
test to find it.

So I guess that means very few people are using Array and Ratio,
or at least we aren't show'ing and read'ing them, or the particular
enclosing precedence value that triggered this bug is very rare.

This has been said before, but maybe we need someone to formulate
a huge set of QuickCheck properties about the Prelude/Libraries.
That would root out quite a lot of remaining bugs relatively quickly
I suspect.

Regards,
    Malcolm