Enum MetadataQuery 

pub enum MetadataQuery<'a> {
    Text(&'a str),
    Matcher(&'a dyn Fn(&str) -> bool),
}

What a Metadata::search asks of one value’s text.

music21 reads a regular expression out of a plain string where it holds any of *.|+?{}, and matches the rest by containment. Nothing here compiles a pattern – the crate carries no regular expression engine – so Self::Text is music21’s plain-string reading alone, and a caller who wants its regular expression hands over a Self::Matcher built from whichever engine they already have.

Variants

Text(&'a str)

A value matches where its text holds this text, either case ignored: music21’s string query.

Matcher(&'a dyn Fn(&str) -> bool)

A value matches where this answers true to its text: music21’s callable query.

Trait Implementations

impl Debug for MetadataQuery<'_>

fn fmt(&self, formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.