Add markdown-table-wrap-pretty: display-only pretty rendering of pipe tables

Makefile

@@ -4,6 +4,11 @@ SHELL := /bin/bash
 EMACS ?= emacs
 BATCH = $(EMACS) --batch -Q -L .
 
+# Source files shipped as packages (each is its own Emacs package).
+SOURCES = markdown-table-wrap.el markdown-table-wrap-pretty.el
+# Test files (features, without the .el extension), each loaded with -l.
+TEST_FILES = markdown-table-wrap-test markdown-table-wrap-pretty-test
+
 # Test selector: run a subset of tests by ERT pattern
 # Example: make test SELECTOR=parse
 SELECTOR ?=
@@ -33,7 +38,7 @@ test:
 	@set -o pipefail; \
 	OUTPUT=$$(mktemp); \
 	$(BATCH) -L test \
-		-l markdown-table-wrap-test \
+		$(patsubst %,-l %,$(TEST_FILES)) \
 		$(if $(SELECTOR),--eval '(ert-run-tests-batch-and-exit "$(SELECTOR)")',-f ert-run-tests-batch-and-exit) \
 		>$$OUTPUT 2>&1; \
 	STATUS=$$?; \
@@ -50,42 +55,51 @@ compile:
 	@echo "=== Byte-compile ==="
 	@$(BATCH) \
 		--eval "(setq byte-compile-error-on-warn t)" \
-		-f batch-byte-compile markdown-table-wrap.el
+		-f batch-byte-compile $(SOURCES)
 
 lint: lint-checkdoc lint-package
 
 lint-checkdoc:
 	@echo "=== Checkdoc ==="
-	@OUTPUT=$$($(BATCH) \
-		--eval "(require 'checkdoc)" \
-		--eval "(setq sentence-end-double-space nil)" \
-		--eval "(checkdoc-file \"markdown-table-wrap.el\")" 2>&1); \
-	WARNINGS=$$(echo "$$OUTPUT" | grep -A1 "^Warning" | grep -v "^Warning\|^--$$"); \
-	if [ -n "$$WARNINGS" ]; then echo "$$WARNINGS"; exit 1; else echo "OK"; fi
+	@STATUS=0; \
+	for f in $(SOURCES); do \
+		OUTPUT=$$($(BATCH) \
+			--eval "(require 'checkdoc)" \
+			--eval "(setq sentence-end-double-space nil)" \
+			--eval "(checkdoc-file \"$$f\")" 2>&1); \
+		WARNINGS=$$(echo "$$OUTPUT" | grep -A1 "^Warning" | grep -v "^Warning\|^--$$"); \
+		if [ -n "$$WARNINGS" ]; then echo "$$WARNINGS"; STATUS=1; fi; \
+	done; \
+	if [ $$STATUS -eq 0 ]; then echo "OK"; else exit 1; fi
 
 lint-package:
 	@echo "=== Package-lint ==="
 	@$(BATCH) \
 		--eval "(require 'package)" \
 		--eval "(push '(\"melpa\" . \"https://melpa.org/packages/\") package-archives)" \
 		--eval "(package-initialize)" \
+		--eval "(package-refresh-contents)" \
 		--eval "(unless (package-installed-p 'package-lint) \
-		          (package-refresh-contents) \
 		          (package-install 'package-lint))" \
 		--eval "(require 'package-lint)" \
 		--eval "(setq package-lint-main-file \"markdown-table-wrap.el\")" \
-		-f package-lint-batch-and-exit markdown-table-wrap.el
+		-f package-lint-batch-and-exit $(SOURCES)
 
 check-parens:
 	@echo "=== Check Parens ==="
 	@OUTPUT=$$($(BATCH) \
-		--eval '(condition-case err \
-		          (with-current-buffer (find-file-noselect "markdown-table-wrap.el") \
-		            (check-parens) \
-		            (message "markdown-table-wrap.el OK")) \
-		          (user-error \
-		           (message "FAIL: %s" (error-message-string err)) \
-		           (kill-emacs 1)))' 2>&1); \
+		--eval '(let ((status 0)) \
+		          (mapc (lambda (f) \
+		                  (condition-case err \
+		                    (with-current-buffer (find-file-noselect f) \
+		                      (check-parens) \
+		                      (message "%s OK" f)) \
+		                    (user-error \
+		                     (message "FAIL: %s: %s" f (error-message-string err)) \
+		                     (setq status 1)))) \
+		                command-line-args-left) \
+		          (kill-emacs status))' \
+		$(SOURCES) 2>&1); \
 	echo "$$OUTPUT" | grep -E "OK$$|FAIL:"; \
 	echo "$$OUTPUT" | grep -q "FAIL:" && exit 1 || true
 

README.org

@@ -8,6 +8,13 @@
 Word-wrap GFM (GitHub Flavored Markdown) pipe tables to fit a
 given character width.  Inline markup survives wrapping.
 
+This repository also ships an OPTIONAL display companion,
+=markdown-table-wrap-pretty= (documented below), which renders tables
+as a wrapped, box-drawing view on top of the canonical raw text (like
+=org-latex-preview= for tables) and toggles between that view and the
+editable source.  It is a separate package and changes nothing unless
+you load it.
+
 #+begin_example
 | Feature   | Status | Notes                         |
 |-----------|--------|-------------------------------|
@@ -149,6 +156,82 @@ Parse and measure once, render at each width:
 - Unicode-aware (CJK, combining marks, VS16 emoji)
 - Pure Elisp, no dependencies
 
+* Optional: pretty display of pipe tables
+
+=markdown-table-wrap-pretty= is a separate, opt-in package shipped in
+this repository.  It renders markdown and org pipe tables as a wrapped,
+Unicode box-drawing "pretty" view ON TOP OF the canonical raw table
+text, and toggles between that view and the raw source in place — the
+table analogue of =org-latex-preview= or inline image previews.
+
+** Why display-only
+
+The buffer text is always the canonical raw pipe table; nothing is
+rewritten.  =markdown-table-wrap= wraps a long cell into multiple
+=| ... |= rows, but pipe-table syntax has no row-spanning, so a real
+renderer (cmark-gfm, pandoc, GitHub, org HTML export) would see those
+as independent data rows.  Mutating the buffer looks right in Emacs but
+is semantically broken the moment the text leaves Emacs.
+=markdown-table-wrap-pretty= keeps the buffer canonical — export,
+copy, share, and push always see a real table — and makes the pretty
+rendering a disposable display layer.
+
+** Commands
+
+| Command | Action |
+|---|---|
+| =markdown-table-wrap-pretty-toggle= | Point-aware toggle: on a table toggles it; off-table toggles all; a region toggles tables in it; a prefix arg forces pretty or raw. |
+| =markdown-table-wrap-pretty-buffer= | Force pretty on every table in the buffer. |
+| =markdown-table-wrap-pretty-region= | Force pretty on every table in the region. |
+| =markdown-table-wrap-pretty-mode= | Buffer-local minor mode: wires the resize re-render hook and optional default-pretty per major mode. |
+
+Editing a pretty table auto-reveals the raw source (via
+=modification-hooks=, the =org-latex-preview= pattern — not
+=read-only=, which would break =undo=), and toggling back re-renders
+fresh from the canonical source.
+
+** Customization
+
+| Option | Default | Meaning |
+|---|---|---|
+| =markdown-table-wrap-pretty-prettify= | =t= | Unicode box-drawing borders; =nil= uses plain ASCII pipes. |
+| =markdown-table-wrap-pretty-auto-rewrap-on-resize= | =t= | Re-render pretty tables on window resize (lossless). |
+| =markdown-table-wrap-pretty-rewrap-idle-delay= | =0.3= | Seconds to debounce resize re-render (=0= is immediate). |
+| =markdown-table-wrap-pretty-default-on-major-modes= | =nil= | Modes where tables start pretty when the minor mode is on. |
+
+** Installation and keys
+
+Load the package (it depends on =markdown-table-wrap=):
+
+#+begin_src elisp
+(require 'markdown-table-wrap-pretty)
+#+end_src
+
+The package ships no default key.  A consistent cross-mode choice is
+=C-c C-x C-k=:
+
+#+begin_src elisp
+(define-key markdown-mode-map (kbd "C-c C-x C-k")
+            #'markdown-table-wrap-pretty-toggle)
+(define-key org-mode-map (kbd "C-c C-x C-k")
+            #'markdown-table-wrap-pretty-toggle)
+#+end_src
+
+Or, with =use-package=, turn it on per major mode:
+
+#+begin_src elisp
+(use-package markdown-table-wrap-pretty
+  :after (markdown-mode org)
+  :hook (markdown-mode . markdown-table-wrap-pretty-mode)
+  :hook (org-mode      . markdown-table-wrap-pretty-mode))
+#+end_src
+
+Detection is universal and line-based, code-fence guarded, with no
+tree-sitter dependency, so it works in =markdown-mode=, =gfm-mode=,
+=md-ts-mode=, and =org-mode=.  Org =|---+---|= separators and width
+cookies are normalized for rendering only; the raw buffer keeps them.
+=#+TBLFM:= formula lines stay visible and untouched while pretty.
+
 * API
 
 ** Primary functions
@@ -180,8 +263,11 @@ The package also exposes =markdown-table-wrap-parse=,
 and =markdown-table-wrap-inside-code-fence-p=.  See their docstrings
 for details.
 
-All public functions are pure (except =inside-code-fence-p=).  No
-=defcustom= is defined; configuration is passed as arguments.
+For the =markdown-table-wrap= engine, all public functions are pure
+(except =inside-code-fence-p=).  No =defcustom= is defined;
+configuration is passed as arguments.  (The optional
+=markdown-table-wrap-pretty= display layer is a separate package with
+its own =defcustom=s; see above.)
 
 * License