Clojure Long Literal String

Question

What I want

Some programming languages have a feature for creating multi-line literal strings, for example:

some stuff ... <<EOF
  this is all part of the string
  as is this
  \ is a literal slash
  \n is a literal \ followed by a literal n
  the string ends on the next line
EOF

Question: Does Clojure have something similar to this? I realize that " handles multi-line fine, but I want it to also properly handle \ as a literal.

Thanks!

score 21 · Answer 1 · edited Sep 16 '16 at 19:56

21

You might be interested in this little function.

(defn long-str [& strings] (clojure.string/join "\n" strings))

You'd use like so

(long-str "This is the first line. Implicitly I want a new line"
          "When I put a new line in the function call to create a new line")

This does require extra double quotes, but would be closer to what you want.

edited Sep 16 '16 at 19:56

Brandon Henry

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answered Mar 27 '15 at 13:07

Virmundi

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Why would you need to create a new function when there's `str`? E.g., `(str "Here is a line.\n" "And a second" "line.")` – celwell Dec 20 '18 at 20:05
@celwell to avoid having to explicitly include the new line character like in your example. Since the goal is to make a logical multi-line, \n is annoying. Clojure should support a `` style where it allows breaks across lines like in Go. – Virmundi Dec 21 '18 at 17:42

score 13 · Answer 2 · edited May 23 '17 at 11:54

13

If you need a \ character in the string, just escape it. You don't have to do anything additional to support multiline strings, for example:

"hello \\
there \\
world "

=> "hello \\\nthere \\\nworld"

EDIT :

Now that you've clarified that you don't want to escape the \ character, I'm afraid that Clojure doesn't offer a special syntax for escaping characters, this has been asked before. In essence, Clojure deals with the same string syntax as Java, with no special syntax available.

edited May 23 '17 at 11:54

Community

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answered Jun 16 '12 at 15:23

Óscar López

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The point is to not have to escape the \ character. I want a literal heredoc. – user1383359 Jun 16 '12 at 16:05
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If you don't care about having to escape the \, then multi-line " already does what you seem to want. – Joost Diepenmaat Jun 16 '12 at 19:16

score 6 · Answer 3 · answered Sep 16 '16 at 19:51

If you really want to do this, put your literal string in a txt file and slurp it up with clojure.

(def my-string (slurp "super_long_string.txt"))

If you want to have it be hot-swappable, slurp it in a function.

(defn my-string [] (slurp "something.sql"))

This way every time you change the raw string, you automatically get its current value in your program by calling (my-string).

Clojure Long Literal String

What I want

3 Answers3