[Haskell-cafe] Random obeservations from my playing with Haskell

Scott Turner p.turner at computer.org
Sun Dec 5 19:51:33 EST 2004


On 2004 December 05 Sunday 18:19, Rolf Wilms wrote:
> [Newbie warning on] Here's a few random obeservations from my playing with
> Haskell:
You've got into Haskell with unusual rapidity. Most of your observations are 
fairly aimed.

> Recently found a memoization modulue in Hugs, but no docs. 
> There's a reference to the Haskell '97 Report, but I didn't find it online. 
http://www.cse.ogi.edu/~jl/ACM/Haskell.html
http://www.cse.ogi.edu/~byron/memo/dispose.ps

> 7. There's a lot of discussion w.r.t state, at least on this list. Is
> threading state through many functions respectivley polluting many
> functions with monads the solution?
If a function is pure, there's never any need to involve it with a monad.  
Monads don't cause "pollution". They serve to indicate what functions have 
side effects, while the choice of monad tells what kinds of side effects may 
occur. 

Haskell people enjoy pure functions, but are not shy of side effects, which 
are recognized as an essential feature of every program. Functions that 
return monadic values provide an excellent way to organize side effects.


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