miguelimo38 at yandex.ru
Fri Nov 27 00:44:56 EST 2009
>> I know that 2 is something of the type Integral, however what does
>> differ from Int? The same question goes for Fractional and
>> Floating, what
>> exactly is their commonality and what exactly is their difference?
> Numeric literals are a special case. To make it possible to write
> "2" and
> mean it as an Int or an Integer (or any other numeric type), 2 is
> to *really* mean (fromIntegral 2). fromIntegral is a function that
> takes an
> Integral value (such as 2), and converts it to a type of your
> choice, so
> long as it's a member of the Num class.
Ahem. 2 is defined to really mean (fromInteger 2), not "fromIntegral".
And "fromInteger" takes an *Integer* value.
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