In clojure can you apply a function to all elements in a collection and have the return value be the input for the next?

Question

Say you have a collection like this ({A: 1 B: 2} {A: 2 B: 5} {A: 4 B: 7}) with an unspecified amount of {A: B:} parts and a function (func arg1 arg2).

If we assume there is some initial state state and that every call to func generates a new-state. Is it possible to construct something that acts like this?

(->(func state {A: 1 B: 2})
(func {A: 2 B: 5}) 
(func {A: 4 B: 7}))

Basically the first argument is the new state and the second is the next {A: B:} from the collection.

Any help would be appreciated!

Answer 1

Yes, this function is called reduce:

(reduce
  func
  initial-state
  input-sequence)

or a version where the first element of the input sequence is used as initial state (check the function doc to see the details of its behaviour):

(reduce 
  func
  input-sequence)

For example:

(reduce
  +
  100
  [1 2 3 4 5])
;; => 115

(reduce
  +
  [1 2 3 4 5])
;; => 15