Double tagged literals at map value result in extra line break

[marksto]

Hi @kkinnear!

The issue I encountered has to do with how Aero-based configuration files are formatted in a certain case.

Here's the minimalistic zprint config I have for this one:

{:width 120
 :style [:justified
         :multi-lhs-hang
         :respect-nl]
 :map   {:indent  0
         :justify {:max-variance 60}
         :comma?  false}}

What I have before running zprint:

{:system/server {:jetty-opts {:port #or [#env PORT 8080]
                              :host #profile {:prod "0.0.0.0"}}}}

What I have after running zprint:

{:system/server
 {:jetty-opts {:port #or [#env PORT 8080]
               :host #profile {:prod "0.0.0.0"}}}}

All is expected and neat.

But, if I add just one extra thing, an Aero tag for the :port value:

{:system/server {:jetty-opts {:port #long #or [#env PORT 8080]
                              :host #profile {:prod "0.0.0.0"}}}}

Then, after running zprint, it quite surprisingly becomes:

{:system/server
 {:jetty-opts
  {:port #long #or [#env PORT 8080]
   :host #profile {:prod "0.0.0.0"}}}}

Which is quite unexpected, I would say, since there is enough space for the :jetty-opts value map to fit on the same line as the key.

I tried out all config options for :tagged-literal, which are few, and none were of help. I also played with all other relevant :map options — still, with no luck.

It seems like these are double tagged literals at map value that result in the extra line break.
I wonder, is there anything that can be done about this?

[kkinnear]

Hello!

In recently ran into issues with tagged literals, and had to completely reimplement them. From the 1.3.0 CHANGELOG.md:

  * Formatting for tagged-literals was completely reimplemented.
  This corrected many problems (not least that they were ignored
  when they appeared in Clojure data structures formatted by zprint
  as a library) and brought the implementation and configuration
  into line with the rest of zprint. Unfortunately, this also caused
  a change to the interpretation of the `:indent` for tagged-literals.
  Previously, the default was `:indent 0`, which would place the
  literal one space to the right of the `#` if it formatted onto
  the line below the tag.  That same placement remains the default,
  but the configuration to generate that output is now `:indent 1`,
  which is an unfortunate but necessary change.  Issue #318.

I was hoping that this might make your situation work better, and indeed:

(czprint i344 {:parse-string? true :width 120, :style [:justified :multi-lhs-hang :respect-nl], :map {:indent 0, :justify {:max-variance 60}, :comma? false}})
{:system/server {:jetty-opts {:port #or [#env PORT 8080]
                              :host #profile {:prod "0.0.0.0"}}}}

(czprint i344a {:parse-string? true :width 120, :style [:justified :multi-lhs-hang :respect-nl], :map {:indent 0, :justify {:max-variance 60}, :comma? false}})
{:system/server {:jetty-opts {:port #long #or [#env PORT 8080]
                              :host #profile {:prod "0.0.0.0"}}}}

It seems to fix the problem that adding the additional tag seemed to generate. Which is nice (to put it mildly). I have no solution for you until 1.3.0 is out, unfortunately.

I'm currently working on implementing :wrap-multi? true for regular lists and vectors (not just in guides) as came up in Issue #341. Turned into an interesting tangle, where I pulled one string and a bunch of others were tied up with it. I think I'm about finished with the heavy lifting for that (tempting fate here) and after cleaning up and writing tests etc I will then push forward to finish out a few outstanding things for1.3.0, which is way overdue.

[marksto]

Wow, this is huge for such a subtle thing — thanks for sharing these "behind the scenes"! Should we close this issue then?

[kkinnear]

I'll close it when I release 1.3.0. Thanks for asking.