[Haskell-cafe] Byte Histogram

Scott Turner 2haskell at pkturner.org
Wed Feb 16 02:32:13 CET 2011


On 2011-02-11 02:06, wren ng thornton wrote:
> And it is clear
> that pointed and unpointed versions are different types[1]. 
...
> [1] Though conversion between them is easy. From unpointed to pointed is
> just a forgetful functor; from pointed to unpointed is the monad of
> evaluation.

I'm unskilled with categories.  For the monad of evaluation, don't the
category's objects need to be strict types?

There was an old thread in which Luke Palmer looked at an implementation
of (>>=) that uses seq to evaluate the left operand. He showed that it's
not a monad.

It would be nice to use a language with rich monads like Haskell, but
with an evaluation monad that fits together with a variety of monad
transformers.  I think this requires strict types. Adding them to
Haskell may not be achievable.



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