prefix minus and infix resolution

[Malcolm Wallace]

> I'm asking for support of:
> http://hackage.haskell.org/trac/haskell-prime/wiki/PrefixMinusResolution

Just to note that nhc98 appears to fulfill the outcome of this  
resolution algorithm already, with the exception of example x7, which  
is parsed as -(4#5).

However, nhc98 goes further and permits the declaration of arbitrary  
prefix operators, using the syntax

     prefix negate 6 -

yes, in addition to

     infix 6 -

I think the rationale is that the prefix symbol must map to a non- 
symbolic function name, because the same symbol may also refer to a  
function of a different type when used infix.  The resolution of  
prefix/infix chains and sections is quite involved, but not enormous:  
see
     http://darcs.haskell.org/york-compiler98/Fixity.hs

Regards,
     Malcolm