Function varsun::posix::substitute

pub fn substitute<F>(src: &str, mapfn: F) -> String where F: Fn(&str) -> Option<String>

Parse src and substitute found variables with result of mapfn.

Examples

use varsun::posix::substitute;

let src = "foo is $foo.";
let res = substitute(src, |name: &str| -> Option<String> {
    match name {
        "foo" => Some("FOO!!".to_string()),
        _     => None,      // If None returns, variable replaces with "" (empty string).
    }
});