exclusiveScan$

Perform exclusive prefix scan from left to right!

Alternatives: exclusiveScan, exclusiveScan$.
Similar: inclusiveScan, exclusiveScan.

function exclusiveScan$(x, fr, acc)
// x:   an array (updated!)
// fr:  reduce function (acc, v, i, x)
// acc: initial value

const xarray = require('extra-array');

var x = [1, 2, 3, 4, 5];
xarray.exclusiveScan$(x, (acc, v) => acc+v, 0); x;
// → [ 0, 1, 3, 6, 10 ]  (x modified!)

var x = [1, 2, 3, 4, 5];
xarray.exclusiveScan$(x, (acc, v) => acc+v, 10); x;
// → [ 10, 11, 13, 16, 20 ]  (x modified!)

References

• std::exclusive_scan() : cppreference.com