Re: [Haskell-cafe] How to decide if a number is an integer?

$ ghci Prelude> let isInteger' l = case properFraction l of { (_,0) -> 1; _ -> 0 } Prelude> isInteger' 2.0 1 Prelude> isInteger' 1.9 0 Do you really get 1? For what input types/values? Although I would write: isInteger = (== 0) . snd . properFraction

It never matches to (_, 0.0).... I mean case properFraction l of (_, 0) -> l _ -> 0 -- always goes here.

On Tue, Sep 29, 2009 at 2:18 PM, Jimmy Hartzell wrote:

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Use properFraction: http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3Aprop...

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Hi,   In other weak-type language, `round i == i` would work. But in haskell, what should I do? Thanks. -- 竹密岂妨流水过 山高哪阻野云飞 _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

-- 竹密岂妨流水过 山高哪阻野云飞