Stop escaping | in LaTeX math.

This caused problems with array environments.  Closes #891.

src/Text/Pandoc/Writers/LaTeX.hs

@@ -212,13 +212,6 @@ stringToLaTeX  isUrl (x:xs) = do
        '\x2013' | ligatures -> "--" ++ rest
        _        -> x : rest
 
--- This is needed because | in math mode interacts badly with
--- highlighting-kate, which redefines | as a short verb command.
-escapeMath :: String -> String
-escapeMath ('|':xs) = "\\vert " ++ escapeMath xs
-escapeMath (x:xs)   = x : escapeMath xs
-escapeMath []       = ""
-
 -- | Puts contents into LaTeX command.
 inCmd :: String -> Doc -> Doc
 inCmd cmd contents = char '\\' <> text cmd <> braces contents
@@ -622,9 +615,9 @@ inlineToLaTeX (Quoted qt lst) = do
                       else char '\x2018' <> inner <> char '\x2019'
 inlineToLaTeX (Str str) = liftM text $ stringToLaTeX False str
 inlineToLaTeX (Math InlineMath str) =
-  return $ char '$' <> text (escapeMath str) <> char '$'
+  return $ char '$' <> text str <> char '$'
 inlineToLaTeX (Math DisplayMath str) =
-  return $ "\\[" <> text (escapeMath str) <> "\\]"
+  return $ "\\[" <> text str <> "\\]"
 inlineToLaTeX (RawInline "latex" str) = return $ text str
 inlineToLaTeX (RawInline "tex" str) = return $ text str
 inlineToLaTeX (RawInline _ _) = return empty

tests/Tests/Writers/LaTeX.hs

@@ -34,6 +34,6 @@ tests = [ testGroup "code blocks"
           ]
         , testGroup "math"
           [ "escape |" =: para (math "\\sigma|_{\\{x\\}}") =?>
-            "$\\sigma\\vert _{\\{x\\}}$"
+            "$\\sigma|_{\\{x\\}}$"
           ]
         ]

tests/lhs-test.latex

@@ -23,7 +23,7 @@
 \usepackage{color}
 \usepackage{fancyvrb}
 \newcommand{\VerbBar}{|}
-\DefineShortVerb[commandchars=\\\{\}]{\|}
+\newcommand{\VERB}{\Verb[commandchars=\\\{\}]}
 \DefineVerbatimEnvironment{Highlighting}{Verbatim}{commandchars=\\\{\}}
 % Add ',fontsize=\small' for more characters per line
 \newenvironment{Shaded}{}{}