wk 6: laziness and infinite structures

what does it mean when haskell is lazy

nothing is computed until its value is actually required

inn inifite lists, how much of it exists

only as much as we ask for it

can you extract finite portions form infinite lists

yes

what does drop 0 do to our list

nothing

what does drop - number do to our list

no effect

what does dropping n on an empty list do to our list

nothing

in drop can we ignore a set of data without needing to generate or evaluate it

yes

what allows us to treat infinite structures as if they were random access for finite windows

take and drop

zipwith

combines two sequences by applying the same operation to corresponding elements

can you zipwith infinite lists with finite lists if yes why

yes you can because zipwith ends as soon as the shorter input ends

how does laziness affect self-reference

normally, self-reference creates infinite recursion but laziness prevents this by only unfolding as much as needed