Function compareTo

Yields the result of comparing a value with a sibling.

const data = [ 1, 2, 4, 8, 16 ];
// Compare values with its previous sibling (-1)
// Since -1 is the offset, the first A and B values will be 2 and 1,
// then 4 and 2, etc.
compareTo(data, -1, (a, b) => b-a)];
// Yields: -1, -2, -4, -8
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Note that one less value is yielded compared to the input array.

You can just as well go forward as well:

const data = [ 1, 2, 4, 8, 16 ];
// Compare values with its next-next sibling (2)
// With an offset of 2, the first A and B values will be 1 and 4, then
// 8 and 2 etc.
// then 4 and 2, etc.
compareTo(data, 2, (a, b) => b-a)];
// Yields: 3, 6, 12
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