Emacs的Clojure功能？

Question

I wondering if there is a set of Emacs Lisp code that implements some of Clojure's functions. For example, -> and ->> and comp and partial, and others?

Thank you.

Answer 1

I've ported the -> and ->> macros to Emacs Lisp a while ago. I use them occasionally in my configuration code and they seem to work fine.

(defmacro -> (e &rest es)
  (if (and (consp es) (not (consp (cdr es))))
      (if (consp (car es))
          `(,(caar es) ,e ,@(cdar es))
        `(,(car es) ,e))
    (if (consp es)
        `(-> (-> ,e ,(car es)) ,@(cdr es))
      e)))

(defmacro ->> (e &rest es)
  (if (and (consp es) (not (consp (cdr es))))
      (if (consp (car es))
          `(,@(car es) ,e)
        `(,(car es) ,e))
    (if (consp es)
        `(->> (->> ,e ,(car es)) ,@(cdr es))
      e)))

Answer 2

You should definitely take a look at dash.el . It provides a lot of Clojure-inspired functions like:

• -map (fn list)
• -reduce-from (fn initial-value list)
• -reduce-r-from (fn initial-value list)
• -reduce (fn list)
• -reduce-r (fn list)
• -filter (pred list)
• -remove (pred list)
• -keep (fn list)
• -map-when (pred rep list)
• -map-indexed (fn list)
• -flatten (l)
• -concat (&rest lists)
• -mapcat (fn list)
• -cons* (&rest args)
• -count (pred list)
• -any? (pred list)
• -all? (pred list)
• -none? (pred list)
• -only-some? (pred list)
• -each (list fn)
• -each-while (list pred fn)
• -dotimes (num fn)
• -repeat (nx)
• -slice (list from &optional to)
• -take (n list)
• -drop (n list)
• -take-while (pred list)
• -drop-while (pred list)
• -split-at (n list)
• -insert-at (nx list)
• -split-with (pred list)
• -separate (pred list)
• -partition (n list)
• -partition-all-in-steps (n step list)
• -partition-in-steps (n step list)
• -partition-all (n list)
• -partition-by (fn list)
• -partition-by-header (fn list)
• -group-by (fn list)
• -interpose (sep list)
• -interleave (&rest lists)
• -zip-with (fn list1 list2)
• -zip (list1 list2)
• -first (pred list)
• -last (pred list)
• -union (list list2)
• -difference (list list2)
• -intersection (list list2)
• -distinct (list)
• -contains? (list element)
• -sort (predicate list)
• -partial (fn &rest args)
• -rpartial (fn &rest args)
• -applify (fn)
• -> (x &optional form &rest more)
• ->> (x form &rest more)
• --> (x form &rest more)
• -when-let (var-val &rest body)
• -when-let* (vars-vals &rest body)
• -if-let (var-val then &optional else)
• -if-let* (vars-vals then &optional else)
• !cons (car cdr)
• !cdr (list)

I find this library extremely useful.

Answer 3

不确定其他人，但部分是在Emacs的lexbind分支中实现为“咖喱”。

Answer 4

I've written these macros recently. They're not recursive and are less verbose. But I haven't tested them extensively yet.

(defmacro ->> (x &rest forms)
  (while forms
      (setq x (append (pop forms) (list x))))
    x)

(defmacro -> (x &rest forms)
  (while forms
    (let ((form (pop forms)))
      (push x (cdr form))
      (setq x form)))
  x)