[Haskell-cafe] Suggestions For An Intro To Monads Talk.

[David Sankel]

On Fri, Aug 6, 2010 at 11:17 AM, aditya siram <aditya.siram at gmail.com>wrote:

> I'm still a little iffy on why the monad concept isn't used in other
> languages.


The greatest feat that monads have accomplished, in my opinion, is providing
the right mathematical abstraction for declaring side-effect and stateful
computation in a pure functional language. For the first time it was now
possible for a pure functional programming language to be a general purpose
programming language. That's was quite an accomplishment!

The second most important feat of monads was their close offspring, the
monad transformers. These guys gave pure functional programmers the ability
to maintain invariants on which side-effect/stateful computations their end
users are going to use. This enhanced verifiability by a measured mix of
pure and impure.

The other languages that you mention are impure. So feat #1 is pointless
since they were already general purpose without monads, and feat #2 is
not realistically achievable since impure languages generally don't have a
way of restricting a function from having arbitrary side-effects.

There have been some clever things done with monads aside from #1 and #2.
Parsec is one, but it seems applicative functors are a better match for the
parsing domain. Other things are "neat", but not killer features that would
turn the head of a pragmatist of the impure type in my opinion.

So, that is why I think the monad concept isn't generally used in other
languages.

David

-- 
David Sankel
Sankel Software
www.sankelsoftware.com
585 617 4748 (Office)
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