You are right, “elf” is a stretch, it does not make sense to parse it as a number. But in some languages, the string “15 240,5” is just how a number is written (yes, that’s a U+2009 THIN SPACE, you can’t stop me from using it as a thousand separator in German).
Alright, maybe you misunderstood the term digits with numbers. When parsing a digit, you do not attach semantic yet to the building blocks. A \d regex parser does not care that the string “555” is not equivalent to “VVV”. All it cares about is that there is the digit “5” or “V”. In the same vein, regex parser should not try to parse IV as a single symbol.
It’s not just digits. Nobody is expecting it to understand language yet but the parser is-number still returns true for "2e3" or "0x0F". It tells you whether the string can be interpreted as a real numeric value.
You are right, “elf” is a stretch, it does not make sense to parse it as a number. But in some languages, the string “15 240,5” is just how a number is written (yes, that’s a
U+2009 THIN SPACE, you can’t stop me from using it as a thousand separator in German).Alright, maybe you misunderstood the term digits with numbers. When parsing a digit, you do not attach semantic yet to the building blocks. A \d regex parser does not care that the string “555” is not equivalent to “VVV”. All it cares about is that there is the digit “5” or “V”. In the same vein, regex parser should not try to parse IV as a single symbol.
It’s not just digits. Nobody is expecting it to understand language yet but the parser
is-numberstill returnstruefor"2e3"or"0x0F". It tells you whether the string can be interpreted as a real numeric value.I feel like there shoul be an ISO/DIN to define this.