(value, elt)
| 2637 | return typeof ctor === "function" && value instanceof ctor; |
| 2638 | } |
| 2639 | nullCheck(value, elt) { |
| 2640 | if (value == null) { |
| 2641 | throw new Error("'" + elt.sourceFor() + "' is null"); |
| 2642 | } |
| 2643 | } |
| 2644 | isEmpty(value) { |
| 2645 | return value == void 0 || value.length === 0; |
| 2646 | } |