Typst writer escaping improvements.

We no longer escape `(`. The reason we did this before (#9137)
has been addressed in another way (#9252).

We only escape `=`, `+`, `-` at the beginning of a line.

We now also escape `/` at the beginning of a line.

This should reduce unnecessary escapes.

Closes #9386.

Author: jgm

src/Text/Pandoc/Writers/Typst.hs

@@ -223,7 +223,7 @@ inlineToTypst inline =
   case inline of
     Str txt -> do
       context <- gets stEscapeContext
-      return $ literal $ escapeTypst context txt
+      return $ escapeTypst context txt
     Space -> return space
     SoftBreak -> do
       wrapText <- gets $ writerWrapText . stOptions
@@ -322,12 +322,17 @@ textstyle :: PandocMonad m => Doc Text -> [Inline] -> TW m (Doc Text)
 textstyle s inlines =
   (<> endCode) . (s <>) . brackets <$> inlinesToTypst inlines
 
-escapeTypst :: EscapeContext -> Text -> Text
+escapeTypst :: EscapeContext -> Text -> Doc Text
 escapeTypst context t =
-  T.replace "//" "\\/\\/" $
-  if T.any needsEscape t
-     then T.concatMap escapeChar t
-     else t
+  (case T.uncons t of
+    Just (c, _)
+      | needsEscapeAtLineStart c
+        -> afterBreak "\\"
+    _ -> mempty) <>
+  (literal (T.replace "//" "\\/\\/"
+    (if T.any needsEscape t
+        then T.concatMap escapeChar t
+        else t)))
   where
     escapeChar c
       | c == '\160' = "~"
@@ -336,7 +341,6 @@ escapeTypst context t =
     needsEscape '\160' = True
     needsEscape '[' = True
     needsEscape ']' = True
-    needsEscape '(' = True -- see #9137
     needsEscape '#' = True
     needsEscape '<' = True
     needsEscape '>' = True
@@ -346,12 +350,16 @@ escapeTypst context t =
     needsEscape '\'' = True
     needsEscape '"' = True
     needsEscape '`' = True
-    needsEscape '=' = True
     needsEscape '_' = True
     needsEscape '*' = True
     needsEscape '~' = True
     needsEscape ':' = context == TermContext
     needsEscape _ = False
+    needsEscapeAtLineStart '/' = True
+    needsEscapeAtLineStart '+' = True
+    needsEscapeAtLineStart '-' = True
+    needsEscapeAtLineStart '=' = True
+    needsEscapeAtLineStart _ = False
 
 toLabel :: Text -> Doc Text
 toLabel ident =

test/command/9386.md

@@ -0,0 +1,17 @@
+```
+% pandoc -t typst --wrap=preserve
+A string of text that is long enough that after 73 chars that includes a
+/ slash creates a newline
+^D
+A string of text that is long enough that after 73 chars that includes a
+\/ slash creates a newline
+```
+
+```
+% pandoc -t typst --wrap=preserve
+A string of text that is long enough that after 73 chars that includes
+a / slash creates a newline
+^D
+A string of text that is long enough that after 73 chars that includes
+a / slash creates a newline
+```

test/writer.typst

@@ -634,9 +634,9 @@ Ellipses…and…and….
 These shouldn’t be math:
 
 - To get the famous equation, write `$e = mc^2$`.
-- \$22,000 is a #emph[lot] of money. So is \$34,000. \(It worked if "lot" is
+- \$22,000 is a #emph[lot] of money. So is \$34,000. (It worked if "lot" is
   emphasized.)
-- Shoes \(\$20) and socks \(\$5).
+- Shoes (\$20) and socks (\$5).
 - Escaped `$`: \$73 #emph[this should be emphasized] 23\$.
 
 Here’s a LaTeX table:
@@ -679,7 +679,7 @@ Left bracket: \[
 
 Right bracket: \]
 
-Left paren: \(
+Left paren: (
 
 Right paren: )
 
@@ -778,7 +778,7 @@ or here: <http://example.com/>
 
 = Images
 <images>
-From "Voyage dans la Lune" by Georges Melies \(1902):
+From "Voyage dans la Lune" by Georges Melies (1902):
 
 #figure([#box(width: 150.0pt, image("lalune.jpg"));],
   caption: [
@@ -796,8 +796,8 @@ Here is a footnote reference,#footnote[Here is the footnote. It can go anywhere
 after the footnote reference. It need not be placed at the end of the document.]
 and another.#footnote[Here’s the long note. This one contains multiple blocks.
 
-Subsequent blocks are indented to show that they belong to the footnote \(as
-with list items).
+Subsequent blocks are indented to show that they belong to the footnote (as with
+list items).
 
 ```
   { <code> }