Function parseBetween

docs/app/js/sanddance-app.js:150048–150065

(s)

    return s[0] === "[" ? parseBetween(s) : parseStream(s);
}
function parseBetween(s) {
    const n = s.length;
    let i = 1, b;
    i = find(s, i, RBRACK, LBRACK, RBRACK);
    if (i === n) throw "Empty between selector: " + s;
    b = parseMerge(s.substring(1, i));
    if (b.length !== 2) throw "Between selector must have two elements: " + s;
    s = s.slice(i + 1).trim();
    if (s[0] !== GT) throw "Expected '>' after between selector: " + s;
    b = b.map(parseSelector);
    const stream = parseSelector(s.slice(1).trim());
    if (stream.between) return {
        between: b,
        stream: stream
    };
    else stream.between = b;
    return stream;
}
function parseStream(s) {
    const stream = {
        source: DEFAULT_SOURCE