I know there has been an old question How can a PetitParser parse rule signal an error?. Lukas Renggli has written it is:

in general this is not good style (mixes syntactic and semantic
analysis)

My question is how to do it with more complex example correctly?

Here is my example:

I want to parse the following term:

(0.53,00)
     ^

I want to tell the user the error is where the ^ points. Something like “please remove the extra comma from your input”

The grammar is:

^ openParenthesis, number, closeParenthesis

The tokens:

openParenthesis
    ^ $( asPParser

number
    ^ wholeNumber plus, dot optional, wholeNumber optional

closeParenthesis
    ^ $) asPParser

wholeNumber 
   ^#digit asPParser plus trim

How would you write a code to detect such (additional comma) kind of error?