Really brief explanation of why Ruby's blocks are awesome

[Insectoid]

I see, so 'true' is 'a' the first time the block is run. 'a&&b' would be 'a' the next time. So this iterates recursively then?

[DtY]

Kinda recursively, say you do:

[A,B,C].inject(true){|a,b| a && b}
It would evaluate to
( (true && A) && B) && C ) )
This might help: http://ruby-doc.org/core/classes/Enumerable.html#M003140

[wtd]

insectoid @ Tue Nov 03, 2009 10:03 am wrote:

I see, so 'true' is 'a' the first time the block is run. 'a&&b' would be 'a' the next time. So this iterates recursively then?

I doubt this is implemented recursively, but it is a gateway drug to functional programming, where it would be done recursively.

code:

let rec inject f init v =     match v with         [] -> init       | x::xs -> inject f (f init x) xs in     inject (fun a b -> a + b) 0 [3; 4; 5]

[apomb]

Thanks DtY, that actually helped alot in understanding enums and blocks.

[Insectoid]

Yeah, I realized that while walking to school today. While recursion would take the problem and work backwards, to find the smallest problem which it CAN solve, this is already at the beginning.