I am very new to clojure and want to make obvious programs.
(def fib (conj fib (apply + (take-last 2 fib)))) Doesn't work because of no lazy evaluation, nor indication of the start being [0 1]
(def fib ( (fn [array] (recur (conj array (apply + (take-last 2 array))))) [0 1])) And here recur is seemingly not lazily evaluated.
Highly related to ( a recursive Fibonacci function in Clojure ) however they use loops and counts or multi-arity. I was wondering if this problem was possible without this.
(def fib (lazy-cat [0 1] (map + fib (rest fib)))) is a very nice solution but somehow hides the operation of fx = fx-1 + fx-2, rather a shift and add all elements. Elegant but not so obvious to the original fibonacci definition.
Is there a way to avoid using map.
obvious is going to be highly subjective, but perhaps this can give you some ideas:
user> (def fib ((fn f [a b] (lazy-seq (cons a (f b (+ a b))))) 0 1))
#'user/fib
user> (take 10 fib)
(0 1 1 2 3 5 8 13 21 34)