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.

[–] ChaoticNeutralCzech@feddit.org 3 points 3 months ago* (last edited 3 months ago) (1 children)

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.

[–] bitfucker@programming.dev 1 points 3 months ago

Yeah, hence is-"number". But we were talking about regex are we. A number representation can use digits but it can also not. Much like how you make a number using the word "elf".