On Sun, 9 Sep 2007, Peter Verswyvelen wrote:
I find it unfortunate that one can't (I guess) define custom unary operators
in Haskell.
Why? What is your application? In fact, alphanumeric identifiers are used
as unary operators.
Is this correct? If so, is this just because eg (* 100) declares a function
that partially applies the * operator, so this syntax disallows unary
operators? Could this be fixed by introducing a different syntax for partial
operator application? E.g. (? * 100) instead of just (*100)?
You can also use "special syntax" for having unary operators. E.g.
(*) :: () -> a -> a
used as ()*100 :-)
This would also fix the ambiguity between (-10) as being either the
number minus 10 or the "subtract by 10' function.
There has been a long discussion whether the unary minus belongs to number
literals or not.
http://www.haskell.org/pipermail/haskell-cafe/2006-September/017941.html
I think that the benefits of prefix or postfix symbolic operators were not
worth dispensing with the comfortable section syntax.
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