clojurec.clj

(defn shell [cmd]
  (-> (Runtime/getRuntime) (.exec cmd)))

(defn is->string [is]
  (let [sb (StringBuilder.)]
    (loop [ch (.read is)]
      (if (= (int ch) -1)
        (.toString sb)
        (do (.append sb (char ch))
          (recur (.read is)))))))

(defmulti clojurec (comp :tag meta))

(defmethod clojurec :proc [p]
  (let [[name- args & body] p
        args (pr-str (into () args))
        return (name (:tag (meta name-)))
        body (apply str (map clojurec body))]
    (format "\n%s %s %s\n{\n%s\n}\n" return name- args body)))

(defmethod clojurec := [assn]
  (let [type (name (:tag (meta (first assn))))
        name- (name (first assn))
        value (second assn)]
    (format "%s %s = %s;\n" type name- value)))

(defmethod clojurec :call [call]
  (let [name (first call)
        args (rest call)]
    (format "%s%s;" name args)))

(defmethod clojurec :c-program [prog]
  (let [body (apply str (map clojurec prog))
        m (meta prog)
        cmd (format "%s %s -o %s" (:compiler m) (:file-name m) (:binary-file m))]
    (with-open [o (-> m :file-name java.io.File. java.io.FileWriter.)]
      (.write o body))
    (shell cmd)
    `(fn [] (shell (format "./%s" ~(:binary-file m))))))

(defmacro cc [x]
  (clojurec x))

;; example
(cc
  #^{:tag :c-program :compiler "gcc" :file-name "test.c" :binary-file "test"}
  [#^:proc (#^:int main []
                #^:= (#^int x 1) 
                #^:call (printf "foo\n"))])
;; at repl

user=> 
(cc
  #^{:tag :c-program :compiler "gcc" :file-name "test.c" :binary-file "test"}
  [#^:proc (#^:int main []
                #^:= (#^int x 1) 
                #^:call (printf "foo\n"))])
#<user$eval__759$fn__761 user$eval__759$fn__761@1b17d49>
user=> (-> *1 (apply nil) .getInputStream is->string)
"foo\n"
user=>