Monads

[Ashley Yakeley]

At 2001-05-17 01:25, Mads Skagen wrote:

>My question is why are monads necessary in the
>language ?
>
>Is it not possible to construct the features provided
>by Monads using basic functional constructs ?

Monads themselves are made purely out of basic functional constructs.

>What do I gain using Monads ?

They happen to be a very convenient pattern. Mostly they're used to model 
imperative actions: while a purely functional language cannot actually 
execute actions as part of its evaluation, it can compose them, along the 
lines of "AB is the action of doing A, and then doing B with its result". 
Monads happen to be a useful pattern for such things.

-- 
Ashley Yakeley, Seattle WA