Sequence patterns

The ... operator recognises more than just arithmetic steps.

If you give it three values that grow by multiplication, it continues with a geometric sequence:

say 1, 2, 4 ... 64; # (1 2 4 8 16 32 64)

Here each value is twice the previous one, so the sequence doubles until it reaches 64.

Sequences are not limited to numbers. With strings, Raku follows the natural alphabetical order:

say 'a' ... 'e'; # (a b c d e)

A sequence can also count downwards. When the endpoint is smaller than the start, the values decrease:

say 10 ... 1; # (10 9 8 7 6 5 4 3 2 1)

In each case you describe the pattern by example, and the ... operator fills in the rest.

Practice

Complete the quiz that covers the contents of this topic.