Builds array from a seed value (dual to foldr).
npm install @extra-array/unfoldrBuilds array from a seed value (dual to foldr).
> This is part of package [extra-array].
[extra-array]: https://www.npmjs.com/package/extra-array
``javascript`
array.unfoldr(x, fn, v);
// fn: unreduce fn (v, i, x)
// v: initial value of accumulator
// --> built array
`javascript
const array = require('extra-array');
array.unfoldr(v => v===0? undefined : [v, v-1], 10);
// [ 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 ]
``