Safe Haskell | Safe |
---|---|
Language | Haskell98 |
- showSigned :: Real a => (a -> ShowS) -> Int -> a -> ShowS
- showIntAtBase :: (Integral a, Show a) => a -> (Int -> Char) -> a -> ShowS
- showInt :: Integral a => a -> ShowS
- showHex :: (Integral a, Show a) => a -> ShowS
- showOct :: (Integral a, Show a) => a -> ShowS
- showEFloat :: RealFloat a => Maybe Int -> a -> ShowS
- showFFloat :: RealFloat a => Maybe Int -> a -> ShowS
- showGFloat :: RealFloat a => Maybe Int -> a -> ShowS
- showFloat :: RealFloat a => a -> ShowS
- floatToDigits :: RealFloat a => Integer -> a -> ([Int], Int)
- readSigned :: Real a => ReadS a -> ReadS a
- readInt :: Num a => a -> (Char -> Bool) -> (Char -> Int) -> ReadS a
- readDec :: (Eq a, Num a) => ReadS a
- readOct :: (Eq a, Num a) => ReadS a
- readHex :: (Eq a, Num a) => ReadS a
- readFloat :: RealFrac a => ReadS a
- lexDigits :: ReadS String
- fromRat :: RealFloat a => Rational -> a
Showing
:: Real a | |
=> (a -> ShowS) | a function that can show unsigned values |
-> Int | the precedence of the enclosing context |
-> a | the value to show |
-> ShowS |
Converts a possibly-negative Real
value to a string.
showIntAtBase :: (Integral a, Show a) => a -> (Int -> Char) -> a -> ShowS
Shows a non-negative Integral
number using the base specified by the
first argument, and the character representation specified by the second.
showEFloat :: RealFloat a => Maybe Int -> a -> ShowS
Show a signed RealFloat
value
using scientific (exponential) notation (e.g. 2.45e2
, 1.5e-3
).
In the call
, if showEFloat
digs valdigs
is Nothing
,
the value is shown to full precision; if digs
is
,
then at most Just
dd
digits after the decimal point are shown.
showFFloat :: RealFloat a => Maybe Int -> a -> ShowS
Show a signed RealFloat
value
using standard decimal notation (e.g. 245000
, 0.0015
).
In the call
, if showFFloat
digs valdigs
is Nothing
,
the value is shown to full precision; if digs
is
,
then at most Just
dd
digits after the decimal point are shown.
showGFloat :: RealFloat a => Maybe Int -> a -> ShowS
Show a signed RealFloat
value
using standard decimal notation for arguments whose absolute value lies
between 0.1
and 9,999,999
, and scientific notation otherwise.
In the call
, if showGFloat
digs valdigs
is Nothing
,
the value is shown to full precision; if digs
is
,
then at most Just
dd
digits after the decimal point are shown.
showFloat :: RealFloat a => a -> ShowS
Show a signed RealFloat
value to full precision
using standard decimal notation for arguments whose absolute value lies
between 0.1
and 9,999,999
, and scientific notation otherwise.
floatToDigits :: RealFloat a => Integer -> a -> ([Int], Int)
floatToDigits
takes a base and a non-negative RealFloat
number,
and returns a list of digits and an exponent.
In particular, if x>=0
, and
floatToDigits base x = ([d1,d2,...,dn], e)
then
n >= 1
x = 0.d1d2...dn * (base**e)
0 <= di <= base-1
Reading
NB: readInt
is the 'dual' of showIntAtBase
,
and readDec
is the `dual' of showInt
.
The inconsistent naming is a historical accident.
readSigned :: Real a => ReadS a -> ReadS a
Reads a signed Real
value, given a reader for an unsigned value.
:: Num a | |
=> a | the base |
-> (Char -> Bool) | a predicate distinguishing valid digits in this base |
-> (Char -> Int) | a function converting a valid digit character to an |
-> ReadS a |
Reads an unsigned Integral
value in an arbitrary base.
readHex :: (Eq a, Num a) => ReadS a
Read an unsigned number in hexadecimal notation. Both upper or lower case letters are allowed.
readFloat :: RealFrac a => ReadS a
Reads an unsigned RealFrac
value,
expressed in decimal scientific notation.