Text.IntFormats

Includes functions for converting from a string to an integer, with the base determined automatically, and from an integer to a string, with the user specifying the base. Supports negative numbers.

For examples, see the test source

parseInt . showInt True _ == Right for all inputs, however the reverse is not necessarily true, even in the case of valid input, since parseInt accepts some rather creative capitalization that showInt does not produce.

Documentation

data IntFormat

IntFormat specifies which base is used for showInt

Constructors

Decimal

0d99, etc. This will be more commonly used without the prefix.

Hexadecimal

Hexadecimal with lowercase digits, such as 0xff

Octal

0o77, etc. In some programs, octal is denoted with a leading zero, however that is not used here.

Binary

0b11, etc.

HexUpper

Hexadecimal with uppercase digits. This only affects the digits A-F, not the prefix. For example, 0xFF

Instances

Eq IntFormat

Methods

(==) :: IntFormat -> IntFormat -> Bool

(/=) :: IntFormat -> IntFormat -> Bool

Show IntFormat

Methods

showsPrec :: Int -> IntFormat -> ShowS

show :: IntFormat -> String

showList :: [IntFormat] -> ShowS

Arbitrary IntFormat

Methods

arbitrary :: Gen IntFormat

shrink :: IntFormat -> [IntFormat]

parseInt :: Integral a => String -> Either String a

Converts a string to an integer if able, otherwise returns an error message. The number may begin with 0x, 0d, 0o, or 0b to specify the numerical base. If no prefix is provided, base 10 is assumed. The prefix is case insensitive. If the number is negative, the sign goes in front of the prefix. The number must not have leading spaces. The number may have characters following it, as long as it is not immediately followed by a digit, a letter, or a decimal point.

intParser :: (Integral a, Stream s m Char) => ParsecT s u m a

The same as parseInt, except the parsec monad isn't evaluated. This is intended for use as part of a larger parser. If you simply want to get a value, use parseInt

showInt

Arguments

:: Integral a

=> Bool

Whether to include the prefix 0x, 0d, 0o, or 0b. A value of True is generally recommended for bases other than decimal.

-> IntFormat

Which numerical base to use, and if it is hexadecimal, whether the digits are uppercase or lowercase

-> a

The number to be converted

-> String

The output value.

Converts a integer to a string, with the chosen numerical base.