Locale-dependent parsing is a bit more complicated. For instance, you likely want to accept locale-specific numerals, and any of 7７ ٧ ৭ 七 match the \d characte

Locale-dependent parsing is a bit more complicated. For instance, you likely want to accept locale-specific numerals, and any of 7７ ٧ ৭ 七 match the \d character class and mean "seven", but you likely don't want to accept a string as a valid number if different types of digits are mixed together. Also, 1,23,456.78 is fine in an Indian locale, but likely is a typo in the en_US or en_UK locales.