Support comments

README.md

@@ -211,6 +211,25 @@ two content slides.
 
 For more information, see [Advanced slide splitting](#advanced-slide-splitting).
 
+Patat supports comments which can be used as speaker notes.
+
+    ---
+    title: This is my presentation
+    author: Jane Doe
+    ...
+
+    # Chapter 1
+
+    <!--
+    Note: I should not bore the audience with my thoughts on powerpoint but
+    just get straight to the point.
+    -->
+
+    Slide contents.  Yay.
+
+    <!-- TODO: Finish the rest of the presentation. -->
+
+
 Configuration
 -------------
 

src/Patat/Presentation/Display.hs

@@ -15,7 +15,7 @@ import           Control.Applicative                  ((<$>))
 import           Control.Monad                        (mplus, unless)
 import qualified Data.Aeson.Extended                  as A
 import           Data.Data.Extended                   (grecQ)
-import           Data.List                            (intersperse)
+import qualified Data.List                            as L
 import           Data.Maybe                           (fromMaybe)
 import           Data.Monoid                          (mconcat, mempty, (<>))
 import qualified Data.Text                            as T
@@ -113,11 +113,11 @@ dumpPresentation :: Presentation -> IO ()
 dumpPresentation pres =
     let theme = fromMaybe Theme.defaultTheme (psTheme $ pSettings pres) in
     PP.putDoc $ withWrapSettings (pSettings pres) $
-        PP.vcat $ intersperse "----------" $ do
+        PP.vcat $ L.intersperse "----------" $ do
             slide <- pSlides pres
             return $ case slide of
                 TitleSlide   block     -> "~~~title" <$$> prettyBlock theme block
-                ContentSlide fragments -> PP.vcat $ intersperse "~~~frag" $ do
+                ContentSlide fragments -> PP.vcat $ L.intersperse "~~~frag" $ do
                     fragment <- fragments
                     return $ prettyFragment theme fragment
 
@@ -238,7 +238,7 @@ prettyBlock theme@Theme {..} (Pandoc.LineBlock inliness) =
 
 --------------------------------------------------------------------------------
 prettyBlocks :: Theme -> [Pandoc.Block] -> PP.Doc
-prettyBlocks theme = PP.vcat . map (prettyBlock theme)
+prettyBlocks theme = PP.vcat . map (prettyBlock theme) . filter isVisibleBlock
 
 
 --------------------------------------------------------------------------------
@@ -327,3 +327,11 @@ isReferenceLink :: Pandoc.Inline -> Bool
 isReferenceLink (Pandoc.Link _attrs text (target, _)) =
     [Pandoc.Str target] /= text
 isReferenceLink _ = False
+
+
+--------------------------------------------------------------------------------
+isVisibleBlock :: Pandoc.Block -> Bool
+isVisibleBlock Pandoc.Null = False
+isVisibleBlock (Pandoc.RawBlock (Pandoc.Format "html") t) =
+    not ("<!--" `L.isPrefixOf` t && "-->" `L.isSuffixOf` t)
+isVisibleBlock _ = True

stack.yaml

@@ -1,4 +1,4 @@
-resolver: lts-11.5
+resolver: lts-11.7
 packages:
 - '.'
 flags:
@@ -7,3 +7,4 @@ flags:
 extra-deps:
 - 'pandoc-2.2'
 - 'pandoc-types-1.17.4.2'
+- 'haddock-library-1.5.0.1'

tests/comments.md

@@ -0,0 +1,16 @@
+# This is a test
+
+Hello world
+
+<!--
+This is a comment so please don't include it.
+-->
+
+# This is a second slide
+
+<!--- Differently-formatted comment -->
+
+Where are my raw blocks at
+
+<!-- Differently-formatted
+comment -->

tests/comments.md.dump

@@ -0,0 +1,8 @@
+# This is a test
+
+Hello world
+
+----------
+# This is a second slide
+
+Where are my raw blocks at