List.gimme

• The List.gimme($n) method
• ensures that at least $n elements of a list have been reified
• generating more elements if needed to meet $n
• returns actual number of reified elements

> 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
> @a.gimme(50);       # force reification of first 50 elements
> say @a[20];             # already reified
10946

• .gimme useful for
• force reification to at least a certain point
• determines how much has already been reified