[Haskell-cafe] Re[2]: strict Haskell dialect

Brian Hulley brianh at metamilk.com
Fri Feb 3 14:33:12 EST 2006

Bulat Ziganshin wrote:
> Hello Wolfgang,
> Friday, February 03, 2006, 1:46:56 AM, you wrote:
>>> i had one idea, what is somewhat corresponding to this discussion:
>>> make a strict Haskell dialect. implement it by translating all
>>> expressions of form "f x" into "f $! x" and then going to the
>>> standard (lazy) haskell translator. the same for data fields - add
>>> to all field definitions "!" in translation process. then add to
>>> this strict
>>> Haskell language ability to _explicitly_ specify lazy fields and
>>> lazy evaluation, for example using this "~" sign

[Apologies for replying to a reply of a reply but I don't seem to have 
received the original post]

I've been thinking along these lines too, because it has always seemed to me 
that laziness is just a real nuisance because it hides a lot of inefficiency 
under the carpet as well as making the time/space behaviour of programs 
difficult to understand...

One question is how to get some kind of "do" notation that would work well 
in a strict setting.
The existing "do" notation makes use of lazyness in so far as the second arg 
of  >> is only evaluated when needed. Perhaps a new keyword such as "go" 
could be used to use >>= instead ie:

go {e1;e2;e3}   ===           e1 >>= (\_-> (e2 >>= (\_->e3)))

Of course this doesn't solve the problem of how to translate programs that 
make heavy use of mapM etc.

I wonder: is monadic programming really dependent on lazyness or is there a 
realistic (ie not impossibly complicated) way to use monads in a strict 

A related question is: could monadic programming ever be as efficient as 
side-effect programming?

Regards, Brian. 

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