Other ways to use zprint

There are a number of other ways to access the formatting capability provided by zprint.

lumo and planck

You can use zprint as a library in either lumo or planck.

zprint-clj (node based)

There is a node based zprint program, zprint-clj which creates an executable that will run zprint on source files. It has slightly different defaults than other programs -- in particular, it does not by default allow "hangs" for expressions. This is because the processing time for zprint is considerably longer if hangs are allowed, because zprint formats everything as a hang and a flow, and compares the results to see which is better. Since zprint-clj is node based, the additional processing time is more costly than it would be using the Java virtual machine

Get zprint-clj

npm i -g zprint-clj

Try zprint-clj

$ zprint-clj -V
0.8.0
$ zprint-clj -h
Usage: zprint-clj [options]

Options:
  -V, --version            output the version number
  -c, --check "<pattern>"  Checks formatting without writing to output, 
                           zprint-clj -c "./out/**/*.{clj,cljs,cljc,edn}"
  -i, --input "<pattern>"  Input file, directory or glob pattern. 
                           If no output specified writes to stdout.
  -o, --out "<path>"       Output path, file or directory
  --hang                   Enable hang mode (better formatting, but 2x slowdown)
  -h, --help               output usage information

Use zprint-clj

$zprint-clj -i "myfile.clj" -o "myfile.1.clj"

Note that the default for this tool is (effectively) {:style :no-hang}, which means that it will never hang anything. This doesn't produce the best looking code, but it does run much faster (about like the graalVM binaries, in fact).

If you can use the pre-built binaries mentioned above, you would probably be wise to do so, since they startup as fast or faster than Javascript/Clojurescript based programs, and run considerably faster.

Startup speed

Casual testing indicates that, on a mid 2012 MacBook Air, zprint-clj 0.8.0 starts up in about 222ms, while zprintm-0.5.4 starts up in about 20ms (after you have used it once).

Proccessing Speed

In additional casual testing, the "... but 2x slowdown" comment in the help, above, seems accurate.

Comparing zprint-clj 0.8.0 with the graalVM binary zprintm-0.5.4, using the defaults, both took about 5 seconds to process a large file (5241 loc). The difference is that zprintm-0.5.4 did this with the normal defaults, that is, it produced code formatted to look as good or better than hand formatted code since hangs were enabled by default. The defaults for zprint-clj are {:style :no-hang}, so the code was not as nice. The same file run through zprint-clj with --hang, to generate output equivalent to zprintm-0.5.4 took about 12 seconds.