Gimme

The .gimme($n) method ensures that at least $n elements of a list have been reified, generating more from a list's iterators if needed. .gimme also returns the actual number of reified elements in a list.

> my @a = 1, 1, *+* ... *;
1 1 2 3 ...
> say @a[8];              # display element at index 8
34
> say @a.gimme(0);        # display number of reified elements
9
> say @a[20];             # display element at index 20
10946
> say @a.gimme(0);        # now how many reified elements?
21             

 .gimme is useful when you want to force reification to at least a certain point, or to determine how much has already been evaluated.