How to print elements in a vector of vectors

问题

I have a vector of vectors, and I want to print elements in each vector

I tried the pprint but did not work as wanted

This is the vector of vectors I wish to print:

[["+" "+" "+" "#" "!" "-" "#" "#" "#" "-" "-" "-" "-"]
 ["!" "#" "+" "+" "+" "#" "+" "+" "+" "-" "#" "#" "-"]
 ["#" "#" "#" "#" "+" "#" "+" "#" "+" "#" "-" "#" "#"]
 ["+" "+" "+" "#" "+" "+" "+" "#" "+" "#" "-" "-" "-"]
 ["+" "#" "+" "#" "#" "#" "#" "+" "+" "-" "#" "#" "-"]
 ["+" "#" "+" "+" "+" "+" "+" "+" "#" "-" "-" "-" "-"]
 ["+" "#" "#" "#" "#" "#" "#" "#" "#" "#" "#" "#" "#"]
 ["+" "+" "+" "+" "+" "+" "+" "+" "+" "+" "+" "+" "@"]]

This is the output I want:

+++#--###--#-
!#+++#+++-##-
####+#+#+#!##
+++#+++#+#!!!
+#+####++!##!
+#++++++#!!!!
+############
++++++++++++@

回答1:

You can use cl-format to handle list (and list of list in this case) with a control string:

(def input
  [["+" "+" "+" "#" "!" "-" "#" "#" "#" "-" "-" "-" "-"]
   ["!" "#" "+" "+" "+" "#" "+" "+" "+" "-" "#" "#" "-"]
   ["#" "#" "#" "#" "+" "#" "+" "#" "+" "#" "-" "#" "#"]
   ["+" "+" "+" "#" "+" "+" "+" "#" "+" "#" "-" "-" "-"]
   ["+" "#" "+" "#" "#" "#" "#" "+" "+" "-" "#" "#" "-"]
   ["+" "#" "+" "+" "+" "+" "+" "+" "#" "-" "-" "-" "-"]
   ["+" "#" "#" "#" "#" "#" "#" "#" "#" "#" "#" "#" "#"]
   ["+" "+" "+" "+" "+" "+" "+" "+" "+" "+" "+" "+" "@"]])

(use 'clojure.pprint)

(cl-format *out* "~{~{~a~}~%~}" input)

Output:

+++#!-###----
!#+++#+++-##-
####+#+#+#-##
+++#+++#+#---
+#+####++-##-
+#++++++#----
+############
++++++++++++@

Explanation: ~a is the format argument of any type. When enclosed in ~{ and ~}, the format argument will be iterated over a list. So when enclosed twice with ~{ and ~}, ~a will be applied over each element (character) in the nested list. The ~% before the last ~} is to output a newline. With this, you can easily change the output with control string. For example:

(cl-format *out* "~{~{(~a)~^ ~}~^~%~%~}" input)

(+) (+) (+) (#) (!) (-) (#) (#) (#) (-) (-) (-) (-)

(!) (#) (+) (+) (+) (#) (+) (+) (+) (-) (#) (#) (-)

(#) (#) (#) (#) (+) (#) (+) (#) (+) (#) (-) (#) (#)

(+) (+) (+) (#) (+) (+) (+) (#) (+) (#) (-) (-) (-)

(+) (#) (+) (#) (#) (#) (#) (+) (+) (-) (#) (#) (-)

(+) (#) (+) (+) (+) (+) (+) (+) (#) (-) (-) (-) (-)

(+) (#) (#) (#) (#) (#) (#) (#) (#) (#) (#) (#) (#)

(+) (+) (+) (+) (+) (+) (+) (+) (+) (+) (+) (+) (@)

Note that "~^" is the directive to stop iteration when a list is run out. So "~^<space>" will suppress the space after the last element in each line. And "~^~%~%" will suppress the double newline after the last line.

回答2:

You don't need any fancy formatting or side-effects (although I do appreciate the information in those answers). Just use clojure.string/join to create the string you want and print it any old way.

> (join "\n" (map join input))
+++#!-###----
!#+++#+++-##-
####+#+#+#-##
+++#+++#+#---
+#+####++-##-
+#++++++#----
+############
++++++++++++@

e.g.

> (let [s (join "\n" (map join input))] (println s))
+++#!-###----
!#+++#+++-##-
####+#+#+#-##
+++#+++#+#---
+#+####++-##-
+#++++++#----
+############
++++++++++++@
nil

回答3:

We can use run! to go over the outer vector and clojure.string/join to turn each inner vector into a printable string.

Assuming your vector is defined as input:

(require '[clojure.string :as str])
(run! (comp println str/join) input)

来源：https://stackoverflow.com/questions/56369017/how-to-print-elements-in-a-vector-of-vectors