Re: Re : Re : [Haskell-cafe] Re: A suggestion for the next high profile Haskell project [Was: Re: What is a hacker?]

On Dec 19, 2006, at 16:03 , minh thu wrote:

2006/12/19, Neil Mitchell :

...

not_term = non_term f x = 12

Now evaluating:

main = f non_term

In a lazy language the value is always 12, in a strict language its always _|_. Now let's inline f:

main = 12

In a lazy language the value is still 12, in a strict language the value has changed. Sorry, I don't see how it has changed. Isn't it still _|_ ? i.e.

No, because inlining f results in the inlined value being 12, where it used to be _|_. Depending on the optimizer, it may well drop the call to non_term entirely because it's not being used (thus changing program semantics), or it may continue to call it (final result will remain _|_ because the inlined value is never reached). -- brandon s. allbery [linux,solaris,freebsd,perl] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH