Function minmax

minmax<T>(object, fn): [T, T] | undefined
Find the minimum and maximum values in an iterable.
Type Parameters
- T
Parameters
- object: Iterable<T>
  The iterable object to search.
- fn: ((first, second) => number)
  The 3-way comparison function to apply to the values. It should return < 0 if the first value is less than the second. 0 if the values are equivalent, or > 0 if the first value is greater than the second.
  - - (first, second): number
    - Parameters
      first: T
      second: T
      Returns number
Returns [T, T] | undefined
A 2-tuple of the [min, max] values in the iterable. If multiple values are equivalent, the left-most values are returned. If the iterable is empty, this returns undefined.

Complexity
Linear.

Example
```
import { minmax } from '@lumino/algorithm';

function numberCmp(a: number, b: number): number {
  return a - b;
}

minmax([7, 4, 0, 3, 9, 4], numberCmp);  // [0, 9]
```
- Defined in find.ts:219