I have often found Haskell's various Num type-classes a little confusing. So I thought I would write a short summary to help myself and hopefully others to make it clearer.
Table of Numeric classes from the Prelude
| Super => | Class | property |
|---|---|---|
Num a |
fromInteger :: Integer -> a |
|
Num, Ord => |
Real a |
toRational :: a -> Rational |
Real, Enum => |
Integral a |
toInteger :: a -> Integer |
Num => |
Fractional a |
fromRational :: Rational -> a |
Fractional => |
Floating a |
exp, log, sin, cosh, ... |
Fractional => |
RealFrac a |
properFraction :: Integral b => a -> (b, a) |
Floating,RealFrac => |
RealFloat a |
decodeFloat :: a -> (Integer, Int) |
(type Rational = Ratio Integer)
Other Numeric types
Complex
Ratio a
Fixed a