Re: [Haskell-cafe] Field updates in a state monad

2008/1/10, Lutz Donnerhacke :

* Michael Roth wrote:

...

Exists there a way to write this cleaner without writing countless "set_xyz" helper functions?

The syntactic sugar for record modifications is simply that: sugar. You might write your own modifier functions: set_bla x y = x { bla = y }

That seems to be exactly what Michael search to avoid. And I don't see any way to do that with the haskell records. Some extension of records may have first-class label though. A pretty interesting alternative could be HList, it has first-class label and a bunch of other good stuff. I never used it though, so I don't know how it affects the performances, if someone could give his experience with it ? -- Jedaï