XQuery, fold: early exit

[ChristianGruen]

If the computed result in a fold function does not change anymore, the remaining computations can be skipped. Examples:

fold-left($huge, 1, fn($result, $item) { true() })
fold-left($huge, 1, fn($result, $item) { $result })
fold-left($huge, 1, fn($result, $item) { if($result > 100) then $result else $result + $item })
fold-left($huge, 1, fn($result, $item) { if($result < 100) then $result + $item else $result })

The same applies to fold-right, array:fold-left and array:fold-right.