Re: [Haskell-cafe] Way to implement toFloat :: (Num a) => a -> Float

Just be careful, realToFrac goes through rational first, which can't represent special values like NaN and Infinity, so those will turn into random numbers. Also it can be very inefficient. Still, it's acceptable for a generic "any to Float" conversion. For conversion between Doubles and Floats (or newtypes thereof), however, I use things like d2f :: Double -> Float d2f (Types.D# d) = Types.F# (Prim.double2Float# d) On Thu, Dec 12, 2013 at 11:55 AM, EatsKittens wrote:

Ah, I had no ideal the real typeclass existed, that completely solves my issue.

On 12 December 2013 20:39, Ben Gamari wrote:

...

EatsKittens writes:

...

Is there a way to add a method to a typeclass like num to implement this concept? A function that converts any number to floats?

Does the following do what you expect?

realToFrac :: (Fractional b, Real a) => a -> b

realToFrac' :: (Real a) => a -> Float realToFrac' = realToFrac :: (Real a) => a -> Float

Cheers,

- Ben

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