Rewrite includes.hs

* It is now a pandoc filter
* It also handles the injection of latex_macros

includes.hs

@@ -2,8 +2,13 @@
 
 import Text.Read
 import Control.Monad.State
-
+import Control.Monad
 import Text.Pandoc
+import Data.Monoid
+import Control.Applicative
+
+import Text.Pandoc.JSON
+import Text.Pandoc.Walk
 
 slice :: Int -> Int -> [a] -> [a]
 slice from to xs = take (to - from + 1) (drop from xs)
@@ -38,9 +43,21 @@ doHtml cb@(CodeBlock (id, classes, namevals) contents) =
        Nothing    -> return cb
 doHtml x = return x
 
+injectLatexMacros :: Maybe Format -> Pandoc -> IO Pandoc
+injectLatexMacros (Just fmt) p = do
+  macros <- readFile "latex_macros"
+  let block =
+        case fmt of
+          Format "html" ->
+            Div ("",[],[("style","display:none")]) . (:[])
+              . Para . (:[]) . Math DisplayMath $ macros
+          Format "latex" -> RawBlock "latex" macros
+  return (Pandoc nullMeta [block] <> p)
+injectLatexMacros _ _ = return mempty
+
 main :: IO ()
-main = getContents >>= return . readMarkdown def
-                   >>= bottomUpM doInclude
-                   >>= bottomUpM doSlice
-                   >>= bottomUpM doHtml
-                   >>= putStrLn . writeMarkdown def
+main = toJSONFilter
+        ((\fmt -> injectLatexMacros fmt
+         >=> walkM doInclude
+         >=> walkM doSlice
+         >=> walkM doHtml) :: Maybe Format -> Pandoc -> IO Pandoc)

latex_macros

@@ -1,5 +1,3 @@
-<div style="display:none">
-$$
 \newcommand{\andalso}{\quad\quad}
 \newcommand{\infabbrev}[2]{\infax{#1 \quad\eqdef\quad #2}}
 \newcommand{\infrule}[2]{\dfrac{#1}{#2}}
@@ -13,7 +11,5 @@ $$
 \newcommand{\BV}[1]{\mathtt{bv}(#1)}
 \newcommand{\compiles}[1]{\text{C}\llbracket{#1}\rrbracket}
 \newcommand{\exec}[1]{\text{E}\llbracket{#1}\rrbracket}
-\newcommand{\t}[1]{\mathtt{#1}}
+\renewcommand{\t}[1]{\mathtt{#1}}
 \newcommand{\ite}[3]{\text{if }#1\text{ then }#2\text{ else }#3}
-$$
-</div>