scanWhileRight

Scan from right, while a test passes.

Alternatives: scanWhile, scanWhileRight, scanUntil, scanUntilRight.
Similar: search, [scan], find.

function scanWhileRight(x, ft)
// x:  an iterable
// ft: test function (v, i, x)

const xiterable = require('extra-iterable');

var x = [1, 1, 2, 2, 3, 3, 4, 4];
xiterable.scanWhileRight(x, v => v % 3 !== 0);
// → 6                     ^

xiterable.scanWhileRight(x, v => v % 2 !== 0);
// → 8                          ^

xiterable.scanWhileRight(x, v => v % 6 !== 0);
// → 0  ^

References

• List-Extra.elemIndex: elm
• binsearch: @krisselden
• binarysearch: @soldair