DRiFT will let you do that, by deriving get_ and set_ methods, but other
than that, no. THere was discussion about a year ago (I think) about
this, with proposed syntax for something, but it never really got off the
ground. You can probably google for it with my name and some other
keywords -- it will likely turn up.
- Hal
On Thu, 6 Nov 2003, Tim Docker wrote:
> One thing that bugs me about the named record syntax, is that with a datatype:
>
> data T = T {
> t_f1 :: X,
> t_f2 :: X
> };
>
> the function t_f1 has the type of an "accessor", ie
>
> t_f1 :: T -> X
>
> but there doesn't any tidy way to get at the "mutator" function
>
> t_f1' :: X -> T -> T
>
> without actually having to write the following
>
> t_f1' x t = t{t_f1=x}
>
> Or is there?
>
>
> Actually mutators of the general form
>
> t_f1' :: (X->X) -> T -> T
> t_f1_ f t = t{t_f1=f (t_f1 t)}
>
> _______________________________________________
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>
--
Hal Daume III | [EMAIL PROTECTED]
"Arrest this man, he talks in maths." | www.isi.edu/~hdaume
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