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RE: [Caml-list] laziness
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Date: 2004-09-06 (09:07)
From: Jason Smith <jns28@s...>
Subject: RE: [Caml-list] laziness
>But that dead code if executed eagerly will result
>in a value stored in a variable which is never used.
>So the code is still 'dead code' and still a bug
>(assuming it is a bug) whether evaluation is eager
>or lazy.

This is where dead code elimination comes into play. A trivial optimization 
performed by the GHC compiler.


let x = <long computation>
    y = ...
in  ...y....

we can remove 'x'.

Again, side-effects make this harder in o'caml.

>Actually the lazy case might make it easier to
>track this down by adding a debugging print
>in the expression -- in the eager case you get
>a diagnostic but can't deduce the result is used,
>in the lazy case you know the result is being used
>when you get the diagnostic.

The compiler should optimize it out. There shouldn't be any need for using 
explicit print statements.


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