Thank does sound like a pain, but it's better than putting fromIntegral all over my code. Why can't Haskell unify a an expected float with an infered int? It seems that this would make life alot easier.
-mike On Sun, Mar 02, 2003 at 11:28:00AM +0000, Jorge Adriano wrote: > > > "Mike T. Machenry" <[EMAIL PROTECTED]> writes: > > > I recently desided I wanted a bunch function to return > > > float instead of Int. [...] I found fromInteger but it > > > didn't seem to work on the return value of the cardinality > > > function for instance. > > > > Try fromIntegral, which works for Int and Integer, too. > > > Casting an Integral value to a Fractional value to perform arithmetic > operations, is a very common need and I don't like adding fromIntegral > everywhere, so ended up writing a (very simple) module with generalized > arithmetic operators (see attachment). The » next to the operations indicate > a cast from an Integral to a Fractional value. > > J.A. > > > module CrossTypeOps where > > > -- Addition > (+«) :: (Fractional a, Integral b)=> a -> b -> a > (+«) x n = x+fromIntegral n > > (»+) :: (Integral a, Fractional b)=> a -> b -> b > (»+) n x = fromIntegral n + x > > (»+«) :: (Integral a, Fractional b)=> a -> a -> b > (»+«) m n = fromIntegral m+fromIntegral n > > > -- Difference > (-«) :: (Fractional a, Integral b)=> a -> b -> a > (-«) x n = x-fromIntegral n > > (»-) :: (Integral a, Fractional b)=> a -> b -> b > (»-) n x = fromIntegral n - x > > (»-«) :: (Integral a, Fractional b)=> a -> a -> b > (»-«) m n = fromIntegral m-fromIntegral n > > > -- Multiplication > (*«) :: (Fractional a, Integral b)=> a -> b -> a > (*«) x n = x*fromIntegral n > > (»*) :: (Integral a, Fractional b)=> a -> b -> b > (»*) n x = fromIntegral n * x > > (»*«) :: (Integral a, Fractional b)=> a -> a -> b > (»*«) m n = fromIntegral m*fromIntegral n > > > -- Division > (/«) :: (Fractional a, Integral b)=> a -> b -> a > (/«) x n = x / fromIntegral n > > (»/) :: (Integral a, Fractional b)=> a -> b -> b > (»/) n x = fromIntegral n / x > > (»/«) :: (Integral a, Fractional b)=> a -> a -> b > (»/«) m n = fromIntegral m / fromIntegral n > > > -- Priorities > infixl 6 +«, »+, »+«, -«, »-, »-« > infixl 7 *«, »*, »*«, /«, »/, »/« > > > _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
