From 26748da6d4fc6912f1ef314fb01f9969d8a5fc59 Mon Sep 17 00:00:00 2001
From: John MacFarlane <fiddlosopher@gmail.com>
Date: Mon, 16 Jul 2012 10:14:43 -0700
Subject: [PATCH] Don't recognize inline-markup starts inside words.

For example, "2*2 = 4*1" should not contain an emphasized
section.  Added test case for "Literal symbols".  Closes #569.
---
 src/Text/Pandoc/Readers/RST.hs | 25 +++++++++++++++++--------
 tests/rst-reader.native        |  4 +++-
 tests/rst-reader.rst           |  4 ++++
 3 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/Text/Pandoc/Readers/RST.hs b/src/Text/Pandoc/Readers/RST.hs
index d1010a736..df063ffd5 100644
--- a/src/Text/Pandoc/Readers/RST.hs
+++ b/src/Text/Pandoc/Readers/RST.hs
@@ -34,7 +34,7 @@ import Text.Pandoc.Definition
 import Text.Pandoc.Shared
 import Text.Pandoc.Parsing
 import Text.ParserCombinators.Parsec
-import Control.Monad ( when, liftM )
+import Control.Monad ( when, liftM, guard )
 import Data.List ( findIndex, intercalate, transpose, sort, deleteFirstsBy )
 import qualified Data.Map as M
 import Text.Printf ( printf )
@@ -58,7 +58,7 @@ underlineChars = "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~"
 
 -- treat these as potentially non-text when parsing inline:
 specialChars :: [Char]
-specialChars = "\\`|*_<>$:[]()-.\"'\8216\8217\8220\8221"
+specialChars = "\\`|*_<>$:/[]{}()-.\"'\8216\8217\8220\8221"
 
 --
 -- parsing documents
@@ -831,12 +831,21 @@ code = try $ do
   return $ Code nullAttr
          $ removeLeadingTrailingSpace $ intercalate " " $ lines result
 
+-- succeeds only if we're not right after a str (ie. in middle of word)
+atStart :: GenParser Char ParserState a -> GenParser Char ParserState a
+atStart p = do
+  pos <- getPosition
+  st <- getState
+  -- single quote start can't be right after str
+  guard $ stateLastStrPos st /= Just pos
+  p
+
 emph :: GenParser Char ParserState Inline
-emph = enclosed (char '*') (char '*') inline >>= 
+emph = enclosed (atStart $ char '*') (char '*') inline >>= 
        return . Emph . normalizeSpaces
 
 strong :: GenParser Char ParserState Inline
-strong = enclosed (string "**") (try $ string "**") inline >>= 
+strong = enclosed (atStart $ string "**") (try $ string "**") inline >>= 
          return . Strong . normalizeSpaces
 
 -- Parses inline interpreted text which is required to have the given role.
@@ -856,7 +865,7 @@ interpreted role = try $ do
   -- http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html#inline-markup-recognition-rules
   -- but it should be good enough for most purposes
   unmarkedInterpretedText = do
-      result <- enclosed (char '`') (char '`') anyChar
+      result <- enclosed (atStart $ char '`') (char '`') anyChar
       return result
 
 superscript :: GenParser Char ParserState Inline
@@ -873,9 +882,9 @@ whitespace = many1 spaceChar >> return Space <?> "whitespace"
 
 str :: GenParser Char ParserState Inline
 str = do
-  result <- many1 (noneOf (specialChars ++ "\t\n "))
-  pos <- getPosition
-  updateState $ \s -> s{ stateLastStrPos = Just pos }
+  let strChar = noneOf ("\t\n " ++ specialChars)
+  result <- many1 strChar
+  updateLastStrPos
   return $ Str result
 
 -- an endline character that can be treated as a space, not a structural break
diff --git a/tests/rst-reader.native b/tests/rst-reader.native
index bf794c849..c99e73f07 100644
--- a/tests/rst-reader.native
+++ b/tests/rst-reader.native
@@ -320,4 +320,6 @@ Pandoc (Meta {docTitle = [Str "Pandoc",Space,Str "Test",Space,Str "Suite",Str ":
 ,Para [Math DisplayMath "\\alpha = beta",Math DisplayMath "E = mc^2"]
 ,Para [Str "Some",Space,Superscript [Str "of"],Space,Str "these",Space,Superscript [Str "words"],Space,Str "are",Space,Str "in",Space,Superscript [Str "superscript"],Str "."]
 ,Para [Str "Reset",Space,Str "default",Str "-",Str "role",Space,Str "to",Space,Str "the",Space,Str "default",Space,Str "default",Str "."]
-,Para [Str "And",Space,Str "now",Space,Str "`",Str "some",Str "-",Str "invalid",Str "-",Str "string",Str "-",Str "3231231",Str "`",Space,Str "is",Space,Str "nonsense",Str "."]]
+,Para [Str "And",Space,Str "now",Space,Str "`",Str "some",Str "-",Str "invalid",Str "-",Str "string",Str "-",Str "3231231",Str "`",Space,Str "is",Space,Str "nonsense",Str "."]
+,Header 2 [Str "Literal",Space,Str "symbols"]
+,Para [Str "2",Str "*",Str "2",Space,Str "=",Space,Str "4",Str "*",Str "1"]]
diff --git a/tests/rst-reader.rst b/tests/rst-reader.rst
index abe6d4f69..4d81ccb85 100644
--- a/tests/rst-reader.rst
+++ b/tests/rst-reader.rst
@@ -593,3 +593,7 @@ Reset default-role to the default default.
 
 And now `some-invalid-string-3231231` is nonsense.
 
+Literal symbols
+---------------
+
+2*2 = 4*1