feat: flag European-style switching of commas for decimals and periods for thousands separators

[hippietrail]

Description

English uses the period . for decimals: 3.141592654 and the comma , for thousands separators: $1,000,000,000
But many European languages do the exact opposite. Many Europeans don't know this or forget it when writing in English and write instead 3,141592654 and $1.000.000.000

Resources

• Wikipedia: Decimal separator

Examples

• 3,141 - What is that? Pi or Three thousand one hundred forty-one? I'm sure it's Pi!
• For example, 1 million can be written: English: 1,000,000.00; Spanish: 1.000.000,00; ISO 31-0: 1 000 000.00
• Worse still: in Germany we officially separate thousands with the decimal point, one million would be 1.000.000 (or 1.000.000,0 as a float)

Potential False Positives

One potential gotcha is with Indian English, where , is used a bit differently to English because in large numbers some groups can be two instead of three. This is related to the use of lakhs and crores in Indian English numbers.