[Haskell-cafe] pure programs

Jules Bean jules at jellybean.co.uk
Wed Nov 5 06:18:53 EST 2008


Jason Dusek wrote:
>   Though that seems reasonable, it is not, in general, true. For
>   example,    System.Info.os    is generally treated as pure,
>   though it is not. It's not clear to me how to disambiguate
>   these "born again" values from really pure values.

It seems to me no one addressed your actual point.

System.Info is broken. "os" has the wrong type.

Sorry about that. There is quite a lot of brokenness in the standard 
libs which stops pure functions being pure. It's a shame IMO.

Jules


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