Org reader: allow changing emphasis syntax

The characters allowed before and after emphasis can be configured via
`#+pandoc-emphasis-pre` and `#+pandoc-emphasis-post`, respectively. This
allows to change which strings are recognized as emphasized text on a
per-document or even per-paragraph basis. The allowed characters must be
given as (Haskell) string.

    #+pandoc-emphasis-pre: "-\t ('\"{"
    #+pandoc-emphasis-post: "-\t\n .,:!?;'\")}["

If the argument cannot be read as a string, the default value is
restored.

Closes: #4378

1 files changed, 6 insertions, 10 deletions

diff --git a/src/Text/Pandoc/Readers/Org/Inlines.hs b/src/Text/Pandoc/Readers/Org/Inlines.hs
index 670f8ace0..3a12f38d0 100644
--- a/src/Text/Pandoc/Readers/Org/Inlines.hs
+++ b/src/Text/Pandoc/Readers/Org/Inlines.hs
@@ -603,6 +603,8 @@ updatePositions :: PandocMonad m
                 => Char
                 -> OrgParser m Char
 updatePositions c = do
+  st <- getState
+  let emphasisPreChars = orgStateEmphasisPreChars st
   when (c `elem` emphasisPreChars) updateLastPreCharPos
   when (c `elem` emphasisForbiddenBorderChars) updateLastForbiddenCharPos
   return c
@@ -681,8 +683,10 @@ emphasisEnd c = try $ do
   updateLastStrPos
   popInlineCharStack
   return c
- where acceptablePostChars =
-           surroundingEmphasisChar >>= \x -> oneOf (x ++ emphasisPostChars)
+ where
+  acceptablePostChars = do
+    emphasisPostChars <- orgStateEmphasisPostChars <$> getState
+    surroundingEmphasisChar >>= \x -> oneOf (x ++ emphasisPostChars)
 
 mathStart :: PandocMonad m => Char -> OrgParser m Char
 mathStart c = try $
@@ -734,14 +738,6 @@ many1TillNOrLessNewlines n p end = try $
 -- here (see, e.g., the Emacs Lisp variable `org-emphasis-regexp-components`
 -- for details).
 
--- | Chars allowed to occur before emphasis (spaces and newlines are ok, too)
-emphasisPreChars :: [Char]
-emphasisPreChars = "-\t ('\"{"
-
--- | Chars allowed at after emphasis
-emphasisPostChars :: [Char]
-emphasisPostChars = "-\t\n .,:!?;'\")}["
-
 -- | Chars not allowed at the (inner) border of emphasis
 emphasisForbiddenBorderChars :: [Char]
 emphasisForbiddenBorderChars = "\t\n\r "