"interact" behaves oddly if used interactively

Jerzy Karczmarczuk karczma at info.unicaen.fr
Wed Oct 1 15:45:51 EDT 2003

Christian Maeder wrote:
> Colin Runciman wrote:
>> Let not the eager imperative tail wag the lazy functional dog!
> Ideally functional programs should be independent of evaluation strategy 
> and I assume that this is the case for about 90% of all Haskell 
> programs. This leaves maybe the head or only the nose for laziness of 
> the "functional dog".


You just proved that you never *needed* laziness in your life.
There is a full-fledged category of functional programs which wouldn't work
without laziness. Saying that it is 10, or 0.1% has simply no sense.

Colin demonstrated one such category.
I need laziness to implement co-recursive data structures for scientific

(If you wish, have another Great Truth:

    "Ideally any programs should be independent of the language used for
     coding them..."

Now, try to convince the world.


Jerzy Karczmarczuk

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