Integer +parsec

integer :: GenTokenParser s u m -> ParsecT s u m Integer
parsec Text.Parsec.Token, parsec Text.ParserCombinators.Parsec.Token
This lexeme parser parses an integer (a whole number). This parser is like natural except that it can be prefixed with sign (i.e. '-' or '+'). Returns the value of the number. The number can be specified in decimal, hexadecimal or octal. The number is parsed according to the grammar rules in the Haskell report.