Indexing
applyO
The circular equivalent of apply.
Note
Given the definition of circular sequence, it returns an element for any possible integer.
Example
Seq(0, 1, 2).applyO(3) // 0
Compared to standard
In the same example the standard version behaves differently, does not return an element, it throws.
Seq(0, 1, 2).apply(3) // IndexOutOfBoundsException
Not a total function
It does not return a value for an empty sequence.
Seq.empty.applyO(0) // ArithmeticException
liftO
The circular equivalent of lift: like applyO, but total. Since any integer is a valid circular index of a non-empty sequence, it returns None only when the sequence is empty.
Example
Seq(0, 1, 2).liftO(3) // Some(0)
Seq.empty[Int].liftO(0) // None
indexOfO
The circular equivalent of indexOf: finds the index of the first element equal to a given value, searching circularly from a circular index (default 0) and wrapping past the end.
Example
Seq(0, 1, 2).indexOfO(0, 1) // 0 — found by wrapping, indexOf(0, 1) would be -1
indexFrom
Converts a circular index into a standard index.
Example
Seq(0, 1, 2).indexFrom(30001) // 1
The source code for this page can be found here.