natural package:parsec

This lexeme parser parses a natural number (a non-negative whole number). 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.
This lexeme parser parses either natural or a float. Returns the value of the number. This parsers deals with any overlap in the grammar rules for naturals and floats. The number is parsed according to the grammar rules defined in the Haskell report.