Fixed bug in Markdown parser: regular $s triggering math mode.

For example:  "shoes ($20) and socks ($5)."

The fix consists in two new restrictions:
+ the $ that ends a math span may not be directly followed by a digit.
+ no blank lines may be included within a math span.

Thanks to Joseph Reagle for noticing the bug.


git-svn-id: https://pandoc.googlecode.com/svn/trunk@1326 788f1e2b-df1e-0410-8736-df70ead52e1b

Text/Pandoc/Readers/Markdown.hs

@@ -873,8 +873,9 @@ math = try $ do
   failIfStrict
   char '$'
   notFollowedBy space
-  words' <- sepBy1 mathWord (many1 space)
+  words' <- sepBy1 mathWord (many1 (spaceChar <|> (newline >>~ notFollowedBy' blankline)))
   char '$'
+  notFollowedBy digit
   return $ Math $ joinWithSep " " words'
 
 emph :: GenParser Char ParserState Inline

tests/testsuite.native

@@ -294,6 +294,7 @@ Pandoc (Meta [Str "Pandoc",Space,Str "Test",Space,Str "Suite"] ["John MacFarlane
 , BulletList
   [ [ Plain [Str "To",Space,Str "get",Space,Str "the",Space,Str "famous",Space,Str "equation,",Space,Str "write",Space,Code "$e = mc^2$",Str "."] ]
   , [ Plain [Str "$",Str "22,000",Space,Str "is",Space,Str "a",Space,Emph [Str "lot"],Space,Str "of",Space,Str "money",Str ".",Space,Str "So",Space,Str "is",Space,Str "$",Str "34,000",Str ".",Space,Str "(It",Space,Str "worked",Space,Str "if",Space,Quoted DoubleQuote [Str "lot"],Space,Str "is",Space,Str "emphasized",Str ".",Str ")"] ]
+  , [ Plain [Str "Shoes",Space,Str "(",Str "$",Str "20)",Space,Str "and",Space,Str "socks",Space,Str "(",Str "$",Str "5)",Str "."] ]
   , [ Plain [Str "Escaped",Space,Code "$",Str ":",Space,Str "$",Str "73",Space,Emph [Str "this",Space,Str "should",Space,Str "be",Space,Str "emphasized"],Space,Str "23",Str "$",Str "."] ] ]
 , Para [Str "Here",Apostrophe,Str "s",Space,Str "a",Space,Str "LaTeX",Space,Str "table:"]
 , Para [TeX "\\begin{tabular}{|l|l|}\\hline\nAnimal & Number \\\\ \\hline\nDog    & 2      \\\\\nCat    & 1      \\\\ \\hline\n\\end{tabular}"]

tests/testsuite.txt

@@ -482,6 +482,7 @@ These shouldn't be math:
 - To get the famous equation, write `$e = mc^2$`.
 - $22,000 is a *lot* of money.  So is $34,000.
   (It worked if "lot" is emphasized.)
+- Shoes ($20) and socks ($5).
 - Escaped `$`:  $73 *this should be emphasized* 23\$.
 
 Here's a LaTeX table:

tests/writer.docbook

@@ -902,6 +902,11 @@ These should not be escaped:  \$ \\ \> \[ \{
           worked if <quote>lot</quote> is emphasized.)
         </para>
       </listitem>
+      <listitem>
+        <para>
+          Shoes ($20) and socks ($5).
+        </para>
+      </listitem>
       <listitem>
         <para>
           Escaped <literal>$</literal>: $73

tests/writer.html

@@ -796,6 +796,8 @@ Blah
 	>lot</em
 	> of money. So is $34,000. (It worked if &ldquo;lot&rdquo; is emphasized.)</li
       ><li
+      >Shoes ($20) and socks ($5).</li
+      ><li
       >Escaped <code
 	>$</code
 	>: $73 <em

tests/writer.latex

@@ -590,6 +590,8 @@ These shouldn't be math:
 \item 
   \$22,000 is a \emph{lot} of money. So is \$34,000. (It worked if
   ``lot'' is emphasized.)
+\item 
+  Shoes (\$20) and socks (\$5).
 \item 
   Escaped \verb!$!: \$73 \emph{this should be emphasized} 23\$.
 \end{itemize}

tests/writer.man

@@ -570,6 +570,8 @@ To get the famous equation, write \f[B]$e\ =\ mc^2$\f[]\.
 $22,000 is a \f[I]lot\f[] of money\. So is $34,000\. (It worked if
 \[lq]lot\[rq] is emphasized\.)
 .IP \[bu] 2
+Shoes ($20) and socks ($5)\.
+.IP \[bu] 2
 Escaped \f[B]$\f[]: $73 \f[I]this should be emphasized\f[] 23$\.
 .PP
 Here's a LaTeX table:

tests/writer.markdown

@@ -507,6 +507,7 @@ These shouldn't be math:
 -   To get the famous equation, write `$e = mc^2$`.
 -   $22,000 is a *lot* of money. So is $34,000. (It worked if "lot"
     is emphasized.)
+-   Shoes ($20) and socks ($5).
 -   Escaped `$`: $73 *this should be emphasized* 23$.
 
 Here's a LaTeX table:

tests/writer.native

@@ -294,6 +294,7 @@ Pandoc (Meta [Str "Pandoc",Space,Str "Test",Space,Str "Suite"] ["John MacFarlane
 , BulletList
   [ [ Plain [Str "To",Space,Str "get",Space,Str "the",Space,Str "famous",Space,Str "equation,",Space,Str "write",Space,Code "$e = mc^2$",Str "."] ]
   , [ Plain [Str "$",Str "22,000",Space,Str "is",Space,Str "a",Space,Emph [Str "lot"],Space,Str "of",Space,Str "money",Str ".",Space,Str "So",Space,Str "is",Space,Str "$",Str "34,000",Str ".",Space,Str "(It",Space,Str "worked",Space,Str "if",Space,Quoted DoubleQuote [Str "lot"],Space,Str "is",Space,Str "emphasized",Str ".",Str ")"] ]
+  , [ Plain [Str "Shoes",Space,Str "(",Str "$",Str "20)",Space,Str "and",Space,Str "socks",Space,Str "(",Str "$",Str "5)",Str "."] ]
   , [ Plain [Str "Escaped",Space,Code "$",Str ":",Space,Str "$",Str "73",Space,Emph [Str "this",Space,Str "should",Space,Str "be",Space,Str "emphasized"],Space,Str "23",Str "$",Str "."] ] ]
 , Para [Str "Here",Apostrophe,Str "s",Space,Str "a",Space,Str "LaTeX",Space,Str "table:"]
 , Para [TeX "\\begin{tabular}{|l|l|}\\hline\nAnimal & Number \\\\ \\hline\nDog    & 2      \\\\\nCat    & 1      \\\\ \\hline\n\\end{tabular}"]

tests/writer.rst

@@ -638,6 +638,7 @@ These shouldn't be math:
 -  To get the famous equation, write ``$e = mc^2$``.
 -  $22,000 is a *lot* of money. So is $34,000. (It worked if "lot"
    is emphasized.)
+-  Shoes ($20) and socks ($5).
 -  Escaped ``$``: $73 *this should be emphasized* 23$.
 
 Here's a LaTeX table:

tests/writer.rtf

@@ -252,6 +252,7 @@ quoted link
 {\pard \ql \f0 \sa180 \li0 \fi0 These shouldn\u8217't be math:\par}
 {\pard \ql \f0 \sa0 \li360 \fi-360 \bullet \tx360\tab To get the famous equation, write {\f1 $e = mc^2$}.\par}
 {\pard \ql \f0 \sa0 \li360 \fi-360 \bullet \tx360\tab $22,000 is a {\i lot} of money. So is $34,000. (It worked if \u8220"lot\u8221" is emphasized.)\par}
+{\pard \ql \f0 \sa0 \li360 \fi-360 \bullet \tx360\tab Shoes ($20) and socks ($5).\par}
 {\pard \ql \f0 \sa0 \li360 \fi-360 \bullet \tx360\tab Escaped {\f1 $}: $73 {\i this should be emphasized} 23$.\sa180\par}
 {\pard \ql \f0 \sa180 \li0 \fi0 Here\u8217's a LaTeX table:\par}
 {\pard \ql \f0 \sa180 \li0 \fi0 \par}

tests/writer.texinfo

@@ -736,6 +736,8 @@ To get the famous equation@comma{} write @code{$e = mc^2$}.
 @item
 $22@comma{}000 is a @emph{lot} of money. So is $34@comma{}000. (It worked if ``lot'' is emphasized.)
 @item
+Shoes ($20) and socks ($5).
+@item
 Escaped @code{$}: $73 @emph{this should be emphasized} 23$.
 @end itemize