Filter overstrikes to Vim help convention.

This allows us to just :set syntax help, and all the
highlighted items are searchable.

1 files changed, 28 insertions, 10 deletions

diff --git a/mnpgr.tl b/mnpgr.tl
index af3541b..72a87b0 100755
--- a/mnpgr.tl
+++ b/mnpgr.tl
@@ -5,14 +5,31 @@
 (defvarl mnpgr-dir (path-cat home-dir ".mnpgr-dir"))
 
 (defvarl vim-commands
-         (join-with "|"
-                    '("hi def link CtrlHUnderline Special"
-                      "hi def link CtrlHBold Keyword"
-                      "set syntax=ctrlh"
-                      "syntax match CtrlHHide /.\\b/  contained conceal"
-                      "set conceallevel=2"
-                      "set concealcursor=nc"
-                      "map q :q!\r")))
+         (join-with "|" '("set syntax=help"
+                          "map q :q!\r")))
+
+(defun make-overstrike-filter (put-string-fn)
+  (let ((cur-mode :norm)
+        (closer ""))
+    (flet ((output-text (str mode)
+             (when (neq mode cur-mode)
+               [put-string-fn closer]
+               (caseq (set cur-mode mode)
+                 (:bold [put-string-fn "*"]
+                        (set closer "*"))
+                 (:ital [put-string-fn "|"]
+                        (set closer "|"))
+                 (:norm (set closer ""))))
+             [put-string-fn str]))
+      (lambda (line)
+        (each ((tok (tok #/.\b./ t line)))
+          (match-case tok
+            ("")
+            (`@{x #/ +/}` (output-text x :norm))
+            (`@x\b@x` (output-text x :bold))
+            (`_\b@x` (output-text x :ital))
+            (@else (output-text else :norm))))
+        (output-text "\n" :norm)))))
 
 (ensure-dir mnpgr-dir)
 
@@ -22,6 +39,7 @@
   (with-resources ((rendered-file (path-cat mnpgr-dir `@page.@section`)
                                   (remove-path rendered-file)))
     (with-stream (s (open-file rendered-file "w"))
-      (whilet ((line (get-line)))
-        (put-line line s)))
+      (let ((ofilt (make-overstrike-filter (lambda (str) (put-string str s)))))
+				(whilet ((line (get-line)))
+          [ofilt line])))
     (sh `vim +'@{vim-commands}' '@{rendered-file}' < /dev/tty`)))