Search for a key in haystack matching predicate pred starting at index
in steps of triangular numbers, 0,1,3,6,10,15,21, ... .
If assumeNonFullHaystack is true it is assumed that at least one element
in haystack matches pred, thereby enabling sentinel-based
probing. Such probing doesn't require in-loop range checking via
indexIncrement != haystack.length and can be made faster.
Search for a key in haystack matching predicate pred starting at index in steps of triangular numbers, 0,1,3,6,10,15,21, ... .
If assumeNonFullHaystack is true it is assumed that at least one element in haystack matches pred, thereby enabling sentinel-based probing. Such probing doesn't require in-loop range checking via indexIncrement != haystack.length and can be made faster.