:: String -> Int -package:hledger-lib -package:speculate -package:express -package:vty package:Cabal -is:exact

Convert to an Int. It is implementation-dependent what fromEnum returns when applied to a value that is too large to fit in an Int.
a constant function, returning the number of digits of floatRadix in the significand
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 using the Read instance. Succeeds if there is exactly one valid result.
>>> readMaybe "123" :: Maybe Int
Just 123
>>> readMaybe "hello" :: Maybe Int
Parse a String with lexemeParsec.