Write clojure macro

Question

I want to program a macro in clojure. The macro is called like this (FORI from to task) e.g. (FORI 1 10 (println i)) and should print the numbers from 1 to 10. So far i have

(defmacro FORI [from to task]
  `(let [i# (range ~from ~to)]
     ~task))

I don´t know how do get the list i# into the (print i).

Thanks for help.

You can see a good overview of Clojure macros here: stackoverflow.com/questions/60212576/… — Alan Thompson
– Alan Thompson, Commented Feb 10, 2022 at 16:15

erdos · Accepted Answer · 2022-02-10 15:46:03Z

2

You can use any symbol in hygienic forms if you unquote their quoted form:

(defmacro fori [from to task]
  `(doseq [~'i (range ~from ~to)]
      ~task))

So here in the expanded form, symbol i will be substituted without change.

Note, using fixed symbols in macros is usually not a good practice, because now i will shadow other vars with the same name.

answered Feb 10, 2022 at 15:46

erdos

3,6032 gold badges22 silver badges32 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

max_sut24 Over a year ago

Thank you very much :) Macros are hard for me as a clojure beginner.

Collectives™ on Stack Overflow

Write clojure macro

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related