Jump to a command, mapping or option source definition from Pentadactyl

barfu

[.pentadactylrc:]
com! jumptodef,jd -literal=1 -nargs=1 -complete help
  \ -js buffer.viewSource(plugins.misc.sourceLocation(args[0]))

[plugins/misc.js:]
function sourceLocation(str) {
    if (isArray(str))
        str = str[0];
    function mapping(s) {
        let [, mc, key] = /(?:(.)_)?(.*)/.exec(s);
        return mappings.get(mc ? modes.modeChars[mc] : modes.NORMAL, key) ||
            dactyl.echoerr("Bad bad: " + s);
    }
    let frame = ((str[0] === ":") ? commands.get(str.substr(1)) :
        /'.*?'/.test(str) ? options.get(str.slice(1,-1)) :
        mapping(str)).definedAt;
    return { url: util.fixURI(frame.filename), line: frame.lineNumber };
}