Generic Instance Method

# lexicographicallyPrecedes(_:by:)

Returns a Boolean value indicating whether the sequence precedes another sequence in a lexicographical (dictionary) ordering, using the given predicate to compare elements.

## Declaration

Available when Bound conforms to Strideable and Bound.Stride conforms to SignedInteger.

## Parameters

`other`

A sequence to compare to this sequence.

`areInIncreasingOrder`

A predicate that returns `true` if its first argument should be ordered before its second argument; otherwise, `false`.

## Return Value

`true` if this sequence precedes `other` in a dictionary ordering as ordered by `areInIncreasingOrder`; otherwise, `false`.

## Discussion

The predicate must be a strict weak ordering over the elements. That is, for any elements `a`, `b`, and `c`, the following conditions must hold:

Complexity: O(m), where m is the lesser of the length of the sequence and the length of `other`.

• `areInIncreasingOrder(a, a)` is always `false`. (Irreflexivity)

• If `areInIncreasingOrder(a, b)` and `areInIncreasingOrder(b, c)` are both `true`, then `areInIncreasingOrder(a, c)` is also `true`. (Transitive comparability)

• Two elements are incomparable if neither is ordered before the other according to the predicate. If `a` and `b` are incomparable, and `b` and `c` are incomparable, then `a` and `c` are also incomparable. (Transitive incomparability)

`func elementsEqual<OtherSequence>(OtherSequence, by: (Bound, OtherSequence.Element) -> Bool) -> Bool`
`func starts<PossiblePrefix>(with: PossiblePrefix, by: (Bound, PossiblePrefix.Element) -> Bool) -> Bool`