Macro dynparser::ematch

macro_rules! ematch {
    (chlist $chars:expr, $(from $from:expr,  to $to:expr),*) => { ... };
    (chlist $chars:expr, from2 $vfrom2:expr) => { ... };
}

Generate a match expression with optional characters and a list of bounds

“String”, from ‘a’, to ‘b’, from ‘c’, to ‘d’ The first string, is a set of chars. Later you can write a list of tuples with ranges to validate

example

#[macro_use]  extern crate dynparser;
use dynparser::parse;

fn main() {
    let rules = rules!{
       "main"   =>  rep!(ematch!(    chlist "cd",
                                        from 'a', to 'b',
                                        from 'j', to 'p'
                    ), 0)
    };

    assert!(parse("aabcdj", &rules).is_ok())
}

You can also pass a list of chars and a vector of char bounds as next example

#[macro_use]  extern crate dynparser;
use dynparser::parse;

fn main() {
    let rules = rules!{
       "main"   =>  rep!(ematch!(    chlist "cd",
                                     from2   vec![
                                            ('a', 'b'),
                                            ('j', 'p')
                                        ]
                    ), 0)
    };

    assert!(parse("aabcdj", &rules).is_ok())
}