scanWhile

Scan from left, while a test passes.

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

function scanWhile(x, ft)
// x:  an array
// ft: test function (v, i, x)

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

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

xarray.scanWhile(x, v => v % 3 !== 0);
// → 4               ^

xarray.scanWhile(x, v => v % 6 !== 0);
// → 8                          ^

References

• List-Extra.elemIndex() : Elm
• iterable-binsearch : @krisselden
• binarysearch : @soldair