`haddock-library` document header level

Document the fact the header level is going to always be between 1 and 6
inclusive. Along the way, I also optimized the parsing code a bit.

2 files changed, 5 insertions, 5 deletions

diff --git a/haddock-library/src/Documentation/Haddock/Parser.hs b/haddock-library/src/Documentation/Haddock/Parser.hs
index 17240792..149ff93d 100644
--- a/haddock-library/src/Documentation/Haddock/Parser.hs
+++ b/haddock-library/src/Documentation/Haddock/Parser.hs
@@ -512,11 +512,11 @@ since = ("@since " *> version <* skipHorizontalSpace <* endOfLine) >>= setSince
 header :: Parser (DocH mod Identifier)
 header = do
   let psers = map (string . flip T.replicate "=") [6, 5 .. 1]
-      pser = choice' psers
-  delim <- T.unpack <$> pser
-  line <- skipHorizontalSpace *> nonEmptyLine >>= return . parseText
+      pser = Parsec.choice psers
+  depth <- T.length <$> pser
+  line <- parseText <$> (skipHorizontalSpace *> nonEmptyLine)
   rest <- try paragraph <|> return DocEmpty
-  return $ DocHeader (Header (length delim) line) `docAppend` rest
+  return $ DocHeader (Header depth line) `docAppend` rest
 
 textParagraph :: Parser (DocH mod Identifier)
 textParagraph = parseText . T.intercalate "\n" <$> some nonEmptyLine
diff --git a/haddock-library/src/Documentation/Haddock/Types.hs b/haddock-library/src/Documentation/Haddock/Types.hs
index 4cf61fee..d8c7a9fa 100644
--- a/haddock-library/src/Documentation/Haddock/Types.hs
+++ b/haddock-library/src/Documentation/Haddock/Types.hs
@@ -79,7 +79,7 @@ data Picture = Picture
   } deriving (Eq, Show)
 
 data Header id = Header
-  { headerLevel :: Int
+  { headerLevel :: Int  -- ^ between 1 and 6 inclusive
   , headerTitle :: id
   } deriving (Eq, Show, Functor, Foldable, Traversable)