The dreaded M-R

John Meacham john at
Sun Jan 29 10:57:38 EST 2006

There are a whole lot of ways to ruin the performance of haskell
programs that are a lot more subtle than the MR restriction. I don't see
why we deem this particular one, especially when it is easily solved by
adding a type signature, of special enough import to change the language

However, If we must have a new syntax then another possibility is that since pattern
matching is already monomorhpic, we can have the 'unary tuple' pattern mean
monomorphic without using any new syntax.

(x) = fromInteger 3

which sort of looks like a unary tuple match and makes it very clear
that only values (and not functions) may be bound in this manner and
the fact that it is shared falls naturally from thinking of it as being
pulled out of a data structure.

I would much prefer something like this as opposed to a new operator. we
are used to = behaving differently when pattern matching vs naming.

John Meacham - ⑆⑆john⑈ 

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