Function keyPrefixMatch

dash/dash-renderer/src/persistence.js:91–95

(prefix, separator)

 * followed by the separator (then anything else)
 */
function keyPrefixMatch(prefix, separator) {
    const fullStr = prefix + separator;
    const fullLen = fullStr.length;
    return key => key === prefix || key.substr(0, fullLen) === fullStr;
}

const UNDEFINED = 'U';
const _parse = val => (val === UNDEFINED ? undefined : JSON.parse(val || null));