The `NumExts` interface collect together various numeric
operations that have proven to be commonly useful

-- Going between Doubles and Floats: doubleToFloat :: Double -> Float floatToDouble :: Float -> Double showHex :: Integral a => a -> ShowS showOct :: Integral a => a -> ShowS showBin :: Integral a => a -> ShowS showIntAtBase :: Integral a => a -- base -> (a -> Char) -- digit to char -> a -- number to show. -> ShowS showListWith :: (a -> ShowS) -> [a] -> ShowS |

Notes:

If

`doubleToFloat`is applied to a`Double`that is within the representable range for`Float`, the result may be the next higher or lower representable`Float`value. If the`Double`is out of range, the result is undefined.No loss of precision occurs in the other direction with

`floatToDouble`, the floating value remains unchanged.`showOct`,`showHex`and`showBin`will prefix`0o`,`0x`and`0b`, respectively. Like`Numeric.showInt`, these show functions work on positive numbers only.`showIntAtBase`is the more general function for converting a number at some base into a series of characters. The above`show*`functions use it, for instance, here's how`showHex`could be definedshowHex :: Integral a => a -> ShowS showHex n r = showString "0x" $ showIntAtBase 16 (toChrHex) n r where toChrHex d | d < 10 = chr (ord '0' + fromIntegral d) | otherwise = chr (ord 'a' + fromIntegral (d - 10))

`showListWith`is strictly speaking not a '`NumExts`' kind of function, but it's sometimes useful in conjunction with the other`show*`functions that`NumExts`exports. It is the non-overloaded version of`showList`, allowing you to supply the`shows`function to use per list element. For instance,

will print out the elements ofputStrLn (NumExts.showListWith NumExts.showHex [0..16])

`[1..16]`in hexadecimal form.