Timeout.parse constructor Null safety

  1. String timeout

Parse the timeout from a user-provided string.

This supports the following formats:

  • Number "x", which produces a relative timeout with the given scale factor.

  • (Number ("d" | "h" | "m" | "s" | "ms" | "us") (" ")?)+, which produces an absolute timeout with the duration given by the sum of the given units.

  • "none", which produces Timeout.none.

Throws a FormatException if timeout is not in a valid format


factory Timeout.parse(String timeout) {
  var scanner = StringScanner(timeout);

  // First check for the string "none".
  if (scanner.scan('none')) {
    return Timeout.none;

  // Scan a number. This will be either a time unit or a scale factor.
  scanner.expect(_untilUnit, name: 'number');
  var number = double.parse((scanner.lastMatch![0])!);

  // A number followed by "x" is a scale factor.
  if (scanner.scan('x') || scanner.scan('X')) {
    return Timeout.factor(number);

  // Parse time units until none are left. The condition is in the middle of
  // the loop because we've already parsed the first number.
  var microseconds = 0.0;
  while (true) {
    scanner.expect(_unit, name: 'unit');
    microseconds += _microsecondsFor(number, (scanner.lastMatch![0])!);


    // Scan the next number, if it's avaialble.
    if (!scanner.scan(_untilUnit)) break;
    number = double.parse((scanner.lastMatch![0])!);

  return Timeout(Duration(microseconds: microseconds.round()));