How to select the regex that matches the first token of a string?

[vnr]

On Saturday, 3 July 2021 at 09:28:32 UTC, user1234 wrote:
> On Saturday, 3 July 2021 at 09:05:28 UTC, vnr wrote:
>> Hello,
>>
>> I am trying to make a small generic lexer that bases its token 
>> analysis on regular expressions. The principle I have in mind 
>> is to define a token type table with its corresponding regular 
>> expression, here is the code I currently have:
>>
>> [...]
>
> storing the regex in a token is an antipattern.

Thank you for the answer,

I know it's not clean, I'll modify my code to define a token type 
table with their regular expression and define a token type table 
with what has match; the former defining the lexer, the latter 
being the result of the latter.

But for now and to keep it simple, I did everything in one.