[Haskell-cafe] More STUArray questions

Roberto Zunino roberto.zunino at sns.it
Mon Mar 13 16:47:58 EST 2006

Martin Percossi wrote:

> matrix.hs:138:27:
>    Couldn't match the rigid variable `.' against `ST'
>      `.' is bound by the type signature for `runSTMatrix'
>      Expected type: ST s
>      Inferred type: . (forall s1)
Something seems wrong here. Above '.' was parsed as an infix type 
variable. As it happens for (x + y) = (+) x y , the parser read (forall 
s . t) as (.) (forall s) t

Also, forall was parsed as a type variable rather than the universal 
quantifier keyword.

Try compiling with -fglasgow-exts .

Roberto Zunino.

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