Selects Unicode numeric characters, including digits from various
scripts, Roman numerals, et cetera.
This function returns
True if its argument has one of the
following
GeneralCategorys, or
False otherwise:
These classes are defined in the
Unicode Character Database,
part of the Unicode standard. The same document defines what is and is
not a "Number".
Examples
Basic usage:
>>> isNumber 'a'
False
>>> isNumber '%'
False
>>> isNumber '3'
True
ASCII
'0' through
'9' are all numbers:
>>> and $ map isNumber ['0'..'9']
True
Unicode Roman numerals are "numbers" as well:
>>> isNumber 'Ⅸ'
True