lisp-parser

(ns recurse.core)

;; TODO most likely add first and list here so that our sample code is fully accounted for
(def lisp->clj {'+ +})

(defn tokenize
  "walks through lisp input string, if current element is not a collection, add it to the vector,
  otherwise create a nested vector by calling tokenize on it"
  [string]
  (mapv (fn [token]
          (if (coll? token)
            (tokenize token)
            token))
        string))

;; test input will now be in our vector format
;; (def test-input (tokenize (read-string "(first (list 1 (+ 2 3) 9))")))

;; test-input

;; (vector? test-input)

;; [first [list 1 [+ 2 3] 9]]


(defn READ []
  (-> (read-line)
      read-string
      tokenize))

(defn EVAL [ast]
  (cond
    (symbol? ast) (get lisp->clj ast ast) ;; if lookup doesn't find anything, return ast
    (vector? ast) (map EVAL ast)
    :else ast))


;; (EVAL test-input)

(defn PRINT [input]
  (println input))


(defn -main
  "lisp parser"
  []
  (-> (READ)
      EVAL
      PRINT))