Confused about typing in ghci

Matthew Danish mdanish at andrew.cmu.edu
Wed Apr 2 17:06:07 EDT 2008


On Wed, Apr 02, 2008 at 04:54:36PM -0400, Patrick Surry wrote:
> Thanks for the quick reply - I'm not sure I really understand exactly
> what your rule means, but it's led me over to
> http://www.haskell.org/haskellwiki/Monomorphism_restriction where it
> seems possible that I might eventually figure it out :)

Really, don't overthink it too much.  Anything that looks like

g = ...

syntactically (that means, as written in the file) cannot have a
polymorphic type-class restricted type (something with a "=>" in the
type).  The distinction being made is that "g = ..." has nothing but
space in between the "g" and the "=".  No parameters syntactically.

> Any thoughts on the other question about where I can go to understand
> Haskell's precedence/associativity rules better (and avoid so many
> parens)?

The Haskell Report, perhaps?

-- 
-- Matthew Danish -- user: mrd domain: cmu.edu
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