[Haskell-cafe] is 256M RAM insufficient for a 20 millionelement Int/Int map?

Luke Palmer lrpalmer at gmail.com
Sun Oct 19 08:04:12 EDT 2008

On Sun, Oct 19, 2008 at 4:26 AM, Claus Reinke <claus.reinke at talk21.com> wrote:
> (hint to ghc hackers: 'Data.Map.Map Int !Int' and '[!a]' would really be useful!-),

I can't figure out what that means though.  Strictness is not a
property of types or of values, it is a property of functions.   [!]
is not a subtype of [] ; IOW, there is no a such that [a] = [!Int]
(where [!Int] is a list with strict values).  For example, if we
allowed this, the following property breaks:

  length xs == length (map f xs)

Since it is not true on strict lists.


More information about the Haskell-Cafe mailing list