exponent package:ghc-lib-parser

exponent corresponds to the second component of decodeFloat. exponent 0 = 0 and for finite nonzero x, exponent x = snd (decodeFloat x) + floatDigits x. If x is a finite floating-point number, it is equal in value to significand x * b ^^ exponent x, where b is the floating-point radix. The behaviour is unspecified on infinite or NaN values.

Parse a string into a significand and exponent according to the "Hexadecimal Floats in Haskell" proposal. A trivial example might be: ghci> readHexSignificandExponentPair "0x1p+1" (1,1) Behaves similar to readSignificandExponentPair but the base is 16 and numbers are given in hexadecimal: ghci> readHexSignificandExponentPair "0xAp-4" (10,-4) ghci> readHexSignificandExponentPair "0x1.2p3" (18,-1)

Parse a string into a significand and exponent. A trivial example might be: ghci> readSignificandExponentPair "1E2" (1,2) In a more complex case we might return a exponent different than that which the user wrote. This is needed in order to use a Integer significand. ghci> readSignificandExponentPair "-1.11E5" (-111,3)