pretty-print not happening despite `racket-pretty-print` set to `t`?

[Daniel Patterson]

I am using doom-emacs, which I don't think messes with the mode much (though I just switched to it, so might be wrong!). I noticed that in the REPL, structs are not pretty printed; I've seen this in emacs before, and the little poking made it seem like the racket-pretty-print variable should maybe control that? either way, reproduction is here:

> (require racket/pretty)
> (apply hash (build-list 20 (lambda (x) x)))
'#hash((0 . 1) (2 . 3) (4 . 5) (6 . 7) (8 . 9) (10 . 11) (12 . 13) (14 . 15) (16 . 17) (18 . 19))
> (pretty-print (apply hash (build-list 20 (lambda (x) x))))
'#hash((0 . 1)
       (2 . 3)
       (4 . 5)
       (6 . 7)
       (8 . 9)
       (10 . 11)
       (12 . 13)
       (14 . 15)
       (16 . 17)
       (18 . 19))

I would have expected those to have been identical?

(Or if I shouldn't have, is there some setting so that I can get that behavior?)

((alist-get 'racket-mode package-alist))
((emacs-version "29.1")
 (system-type darwin)
 (x-gtk-use-system-tooltips UNDEFINED)
 (major-mode help-mode)
 (racket--el-source-dir "/Users/dbp/.config/emacs/.local/straight/build-29.1/racket-mode/")
 (racket--rkt-source-dir "/Users/dbp/.config/emacs/.local/straight/build-29.1/racket-mode/racket/")
 (racket-program "racket")
 (racket-command-timeout 10)
 (racket-path-from-emacs-to-racket-function UNDEFINED)
 (racket-path-from-racket-to-emacs-function UNDEFINED)
 (racket-browse-url-function racket-browse-url-using-temporary-file)
 (racket-documentation-search-location "https://docs.racket-lang.org/search/index.html?q=%s")
 (racket-xp-after-change-refresh-delay 1)
 (racket-xp-mode-lighter
  (:eval
   (racket--xp-mode-lighter)))
 (racket-xp-highlight-unused-regexp "^[^_]")
 (racket-repl-buffer-name-function nil)
 (racket-submodules-to-run
  ((test)
   (main)))
 (racket-memory-limit 2048)
 (racket-error-context medium)
 (racket-repl-history-directory "~/.config/emacs/.local/cache/racket-mode/")
 (racket-history-filter-regexp "\\`\\s *\\'")
 (racket-images-inline t)
 (racket-imagemagick-props nil)
 (racket-images-keep-last 100)
 (racket-images-system-viewer "open")
 (racket-pretty-print t)
 (racket-use-repl-submit-predicate nil)
 (racket-pretty-print t)
 (racket-indent-curly-as-sequence t)
 (racket-indent-sequence-depth 0)
 (racket-pretty-lambda nil)
 (racket-smart-open-bracket-enable nil)
 (racket-module-forms "\\s(\\(?:module[*+]?\\|library\\)")
 (racket-logger-config
  ((cm-accomplice . warning)
   (GC . info)
   (module-prefetch . warning)
   (optimizer . info)
   (racket/contract . error)
   (racket-mode-debugger . info)
   (sequence-specialization . info)
   (* . fatal)))
 (racket-show-functions
  (racket-show-pseudo-tooltip)))
(enabled-minor-modes
 (+popup-mode)
 (auto-composition-mode)
 (auto-compression-mode)
 (auto-encryption-mode)
 (auto-fill-mode)
 (auto-save-mode)
 (better-jumper-local-mode)
 (better-jumper-mode)
 (buffer-read-only)
 (column-number-mode)
 (delete-selection-mode)
 (doom-modeline-mode)
 (electric-indent-mode)
 (eros-mode)
 (file-name-shadow-mode)
 (font-lock-mode)
 (gcmh-mode)
 (general-override-mode)
 (global-company-mode)
 (global-eldoc-mode)
 (global-flycheck-mode)
 (global-font-lock-mode)
 (global-git-commit-mode)
 (global-hl-line-mode)
 (global-so-long-mode)
 (global-visual-line-mode)
 (hl-line-mode)
 (isearch-fold-quotes-mode)
 (line-number-mode)
 (marginalia-mode)
 (menu-bar-mode)
 (mouse-wheel-mode)
 (ns-auto-titlebar-mode)
 (override-global-mode)
 (persp-mode)
 (projectile-mode)
 (recentf-mode)
 (save-place-mode)
 (savehist-mode)
 (semantic-minor-modes-format)
 (server-mode)
 (shell-dirtrack-mode)
 (show-paren-mode)
 (size-indication-mode)
 (smartparens-global-mode)
 (solaire-global-mode)
 (solaire-mode)
 (transient-mark-mode)
 (undo-fu-mode)
 (undo-fu-session-global-mode)
 (vertico-mode)
 (visual-line-mode)
 (volatile-highlights-mode)
 (which-key-mode)
 (window-divider-mode)
 (winner-mode)
 (ws-butler-global-mode)
 (yas-global-mode)
 (yas-minor-mode))
(disabled-minor-modes
 (+emacs-lisp-ert-mode)
 (+emacs-lisp-non-package-mode)
 (+org-pretty-mode)
 (+popup-buffer-mode)
 (abbrev-mode)
 (anzu-mode)
 (auto-fill-function)
 (auto-revert-mode)
 (auto-revert-tail-mode)
 (auto-save-visited-mode)
 (blink-cursor-mode)
 (buffer-face-mode)
 (bug-reference-mode)
 (bug-reference-prog-mode)
 (button-mode)
 (cl-old-struct-compat-mode)
 (comint-fontify-input-mode)
 (company-mode)
 (company-search-mode)
 (compilation-minor-mode)
 (compilation-shell-minor-mode)
 (completion-in-region-mode)
 (consult-preview-at-point-mode)
 (context-menu-mode)
 (cursor-face-highlight-mode)
 (cursor-intangible-mode)
 (cursor-sensor-mode)
 (dash-fontify-mode)
 (defining-kbd-macro)
 (diff-auto-refine-mode)
 (diff-minor-mode)
 (dired-hide-details-mode)
 (display-line-numbers-mode)
 (dtrt-indent-global-mode)
 (dtrt-indent-mode)
 (eldoc-mode)
 (electric-layout-mode)
 (electric-quote-mode)
 (flycheck-mode)
 (flycheck-popup-tip-mode)
 (flymake-mode)
 (general-override-local-mode)
 (git-commit-mode)
 (git-gutter-mode)
 (global-anzu-mode)
 (global-auto-revert-mode)
 (global-dash-fontify-mode)
 (global-display-line-numbers-mode)
 (global-git-gutter-mode)
 (global-goto-address-mode)
 (global-hide-mode-line-mode)
 (global-hl-todo-mode)
 (global-prettify-symbols-mode)
 (global-reveal-mode)
 (global-semantic-highlight-edits-mode)
 (global-semantic-highlight-func-mode)
 (global-semantic-show-parser-state-mode)
 (global-semantic-show-unmatched-syntax-mode)
 (global-semantic-stickyfunc-mode)
 (global-vi-tilde-fringe-mode)
 (global-whitespace-mode)
 (global-whitespace-newline-mode)
 (goto-address-mode)
 (goto-address-prog-mode)
 (header-line-indent-mode)
 (hide-mode-line-mode)
 (highlight-numbers-mode)
 (highlight-quoted-mode)
 (hl-todo-mode)
 (horizontal-scroll-bar-mode)
 (hs-minor-mode)
 (ibuffer-auto-mode)
 (indent-tabs-mode)
 (isearch-mode)
 (ispell-minor-mode)
 (jit-lock-debug-mode)
 (lock-file-mode)
 (lost-selection-mode)
 (magit-auto-revert-mode)
 (magit-blame-mode)
 (magit-blame-read-only-mode)
 (magit-blob-mode)
 (magit-todos-mode)
 (magit-wip-after-apply-mode)
 (magit-wip-after-save-local-mode)
 (magit-wip-after-save-mode)
 (magit-wip-before-change-mode)
 (magit-wip-initial-backup-mode)
 (magit-wip-mode)
 (mail-abbrevs-mode)
 (merlin-mode)
 (mml-mode)
 (next-error-follow-minor-mode)
 (org-capture-mode)
 (org-cdlatex-mode)
 (org-list-checkbox-radio-mode)
 (org-src-mode)
 (org-table-follow-field-mode)
 (org-table-header-line-mode)
 (orgtbl-mode)
 (outline-minor-mode)
 (overwrite-mode)
 (paragraph-indent-minor-mode)
 (pcre-mode)
 (prettify-symbols-mode)
 (racket-smart-open-bracket-mode)
 (racket-xp-mode)
 (rainbow-delimiters-mode)
 (read-extended-command-mode)
 (reveal-mode)
 (rxt--read-pcre-mode)
 (rxt-global-mode)
 (rxt-mode)
 (semantic-highlight-edits-mode)
 (semantic-highlight-func-mode)
 (semantic-mode)
 (semantic-show-parser-state-mode)
 (semantic-show-unmatched-syntax-mode)
 (semantic-stickyfunc-mode)
 (sh-electric-here-document-mode)
 (shell-command-with-editor-mode)
 (shell-highlight-undef-mode)
 (show-smartparens-global-mode)
 (show-smartparens-mode)
 (smartparens-global-strict-mode)
 (smartparens-mode)
 (smartparens-strict-mode)
 (smerge-mode)
 (so-long-minor-mode)
 (tab-bar-history-mode)
 (tab-bar-mode)
 (temp-buffer-resize-mode)
 (text-scale-mode)
 (tool-bar-mode)
 (tooltip-mode)
 (transient-resume-mode)
 (treesit-explore-mode)
 (treesit-inspect-mode)
 (undelete-frame-mode)
 (undo-fu-session-mode)
 (url-handler-mode)
 (use-hard-newlines)
 (utop-minor-mode)
 (vc-dir-git-mode)
 (vc-parent-buffer)
 (vi-tilde-fringe-mode)
 (view-mode)
 (visible-mode)
 (which-function-mode)
 (whitespace-mode)
 (whitespace-newline-mode)
 (with-editor-mode)
 (ws-butler-mode)
 (xref-etags-mode))

[Greg Hendershott]

Thanks for the report.

You can create a REPL buffer two ways:

1. From a racket-run command. This is the main, intended use case for the REPL.

2. From a racket-repl command. As its doc string says, you can do this but there are caveats.

Show a Racket REPL buffer in some window.

IMPORTANT

The main, intended use of Racket Mode's REPL is that you
find-file some specific .rkt file, then run it using
racket-run or racket-run-module-at-point. The resulting REPL
will correspond to those definitions and match your expectations.

If you really want to start a REPL for no file in particular,
then you could use this racket-repl command. But the resulting
REPL will have a minimal "#lang racket/base" namespace. You
could enter "(require racket)" if you want the equivalent of
"#lang racket". You could also "(require racket/enter)" if
you want things like "enter!". But in some sense you'd be
"using it wrong". If you actually don't want to use Racket
Mode's REPL as intended, then consider using a plain Emacs
shell buffer to run command-line Racket.

Although the doc string doesn't include this among the caveats, a bunch of settings get conveyed from Emacs variables to the Racket Mode back end process as part of a run command. These include:

• racket-pretty-print 👈
• racket-memory-limit
• racket-error-context
• racket-submodules-to-run
• racket-user-command-line-arguments

This doesn't happen with the racket-repl command.

So that's the explanation, and you have an idea for a work-around.

---

Instead?

• I could document these extra caveat for the racket-repl command. But not everyone reads the doc string. And anyway this isn't really an improvement, it's just documenting a lack of improvement. 😄

• A real improvement might be for the racket-repl command to do a run command, just to convey these values.

  • Maybe this runs no actual file.
  • Maybe this could run a user-supplied racket-repl.rkt file if it exists, i.e. a kind of init file for the REPL. (You could do this today with racket-run, manually, of course.)

• I guess another option is to print a message in the REPL buffer, ~= "This racket-repl command buffer has limits; see the doc string" and maybe even linkify that to the doc string.

[Daniel Patterson]

Ahh -- that helps clarify a lot. I think if there were a message along the lines of "Running racket-repl on its own has limited settings; you may want to use racket-run on a buffer instead" or something like that when you ran the standalone, that might be helpful.

(Also, most of the time you want contents of the file... it just so happens that I was testing out some stuff that I hadn't written into a file, so didn't need that, or I probably wouldn't have gotten myself into this trouble.)

[Greg Hendershott]

I just pushed a commit 5a69b3f to a topic branch, which does one option I mentioned above: Change racket-repl into a command that just runs a certain "init" file. (The name and contents of which a user can customize, of course).

This seems so obviously the right thing to do instead, that I'm a little suspicious and want to sleep on it before merging. 😄 But it worked well in my initial testing, and I think this is at least in the right ballpark.

[Greg Hendershott]

I went through a few rounds of dog-fooding this and fine-tuning, but ended up merging what I described above.

This addresses the specific issue you reported.

It also allows customizing a .rkt (or for that matter .rhm or whatever extension file with a #lang line) which is the file run when you M-x racket-repl. So it acts as a kind of little init file. I think in the past a few people have asked for something like this.

[Daniel Patterson]

Thank you! This is great.