How to create a parser which means any char not in ['(',')','{','}'], in PetitParserDart?

Question

I want to define a parser which accept any char except ['(', ')', '{', '}'] in PetitParserDart.

I tried:

char('(').not() & char(')').not() & char('{').not() & char('}')

I'm not sure if it's correct, and is it any simple way to do this? (something like chars('(){}').neg()) ?

Answer 1

This matches anything, but the characters listed after the caret ^. It is the character class of all characters without the listed ones:

pattern('^(){}');

This also works (note the .not() on the last character, and the any() to actually consume the character):

char('(').not() & char(')').not() & char('{').not() & char('}').not() & any()

And this one works as well:

anyIn('(){}').neg()

Which is equivalent to:

(anyIn('(){}').not() & any()).pick(1)

And another alternative is:

(char('(') | char(')') | char('{') | char('}')).neg()

Except for the second example, all examples return the parsed character (this can be easily fixed, but I wanted to stay close to your question). The first example is probably the easiest to understand, but depending on context you might prefer one of the alternatives.