diff --git a/README b/README
index 160fc539e..0df8e8d26 100644
--- a/README
+++ b/README
@@ -2785,6 +2785,11 @@ in several respects:
we must either disallow lazy wrapping or require a blank line between
list items.
+#### Extension: `shortcut_reference_links` ####
+
+Allows to use shortcut reference links: `[foo]` instead of `[foo][]`. Writer
+would shortcut links unless doing so might cause problems.
+
Markdown variants
-----------------
diff --git a/src/Text/Pandoc/Options.hs b/src/Text/Pandoc/Options.hs
index 24e31fbb6..48803d36f 100644
--- a/src/Text/Pandoc/Options.hs
+++ b/src/Text/Pandoc/Options.hs
@@ -109,6 +109,7 @@ data Extension =
| Ext_implicit_header_references -- ^ Implicit reference links for headers
| Ext_line_blocks -- ^ RST style line blocks
| Ext_epub_html_exts -- ^ Recognise the EPUB extended version of HTML
+ | Ext_shortcut_reference_links -- ^ Shortcut reference links
deriving (Show, Read, Enum, Eq, Ord, Bounded)
pandocExtensions :: Set Extension
@@ -151,6 +152,7 @@ pandocExtensions = Set.fromList
, Ext_header_attributes
, Ext_implicit_header_references
, Ext_line_blocks
+ , Ext_shortcut_reference_links
]
phpMarkdownExtraExtensions :: Set Extension
@@ -164,6 +166,7 @@ phpMarkdownExtraExtensions = Set.fromList
, Ext_intraword_underscores
, Ext_header_attributes
, Ext_abbreviations
+ , Ext_shortcut_reference_links
]
githubMarkdownExtensions :: Set Extension
@@ -180,6 +183,7 @@ githubMarkdownExtensions = Set.fromList
, Ext_strikeout
, Ext_hard_line_breaks
, Ext_lists_without_preceding_blankline
+ , Ext_shortcut_reference_links
]
multimarkdownExtensions :: Set Extension
@@ -202,7 +206,9 @@ multimarkdownExtensions = Set.fromList
strictExtensions :: Set Extension
strictExtensions = Set.fromList
- [ Ext_raw_html ]
+ [ Ext_raw_html
+ , Ext_shortcut_reference_links
+ ]
data ReaderOptions = ReaderOptions{
readerExtensions :: Set Extension -- ^ Syntax extensions
diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs
index 910936b34..9e6ad0e13 100644
--- a/src/Text/Pandoc/Readers/Markdown.hs
+++ b/src/Text/Pandoc/Readers/Markdown.hs
@@ -1679,6 +1679,7 @@ referenceLink constructor (lab, raw) = do
lookAhead (try (spnl >> normalCite >> return (mempty, "")))
<|>
try (spnl >> reference)
+ when (raw' == "") $ guardEnabled Ext_shortcut_reference_links
let labIsRef = raw' == "" || raw' == "[]"
let key = toKey $ if labIsRef then raw else raw'
parsedRaw <- parseFromString (mconcat <$> many inline) raw'
diff --git a/src/Text/Pandoc/Writers/Markdown.hs b/src/Text/Pandoc/Writers/Markdown.hs
index 662373209..15c6d9fb5 100644
--- a/src/Text/Pandoc/Writers/Markdown.hs
+++ b/src/Text/Pandoc/Writers/Markdown.hs
@@ -57,14 +57,15 @@ import qualified Data.Text as T
type Notes = [[Block]]
type Refs = [([Inline], Target)]
-data WriterState = WriterState { stNotes :: Notes
- , stRefs :: Refs
- , stInList :: Bool
- , stIds :: [String]
- , stPlain :: Bool }
+data WriterState = WriterState { stNotes :: Notes
+ , stRefs :: Refs
+ , stRefShortcutable :: Bool
+ , stInList :: Bool
+ , stIds :: [String]
+ , stPlain :: Bool }
instance Default WriterState
- where def = WriterState{ stNotes = [], stRefs = [], stInList = False,
- stIds = [], stPlain = False }
+ where def = WriterState{ stNotes = [], stRefs = [], stRefShortcutable = True,
+ stInList = False, stIds = [], stPlain = False }
-- | Convert Pandoc to Markdown.
writeMarkdown :: WriterOptions -> Pandoc -> String
@@ -690,27 +691,47 @@ getReference label (src, tit) = do
inlineListToMarkdown :: WriterOptions -> [Inline] -> State WriterState Doc
inlineListToMarkdown opts lst = do
inlist <- gets stInList
- mapM (inlineToMarkdown opts)
- (if inlist then avoidBadWraps lst else lst) >>= return . cat
- where avoidBadWraps [] = []
- avoidBadWraps (Space:Str ('>':cs):xs) =
- Str (' ':'>':cs) : avoidBadWraps xs
- avoidBadWraps (Space:Str [c]:[])
- | c `elem` "-*+" = Str [' ', c] : []
- avoidBadWraps (Space:Str [c]:Space:xs)
- | c `elem` "-*+" = Str [' ', c] : Space : avoidBadWraps xs
- avoidBadWraps (Space:Str cs:Space:xs)
- | isOrderedListMarker cs = Str (' ':cs) : Space : avoidBadWraps xs
- avoidBadWraps (Space:Str cs:[])
- | isOrderedListMarker cs = Str (' ':cs) : []
- avoidBadWraps (x:xs) = x : avoidBadWraps xs
- isOrderedListMarker xs = endsWithListPunct xs &&
- isRight (runParserT (anyOrderedListMarker >> eof)
- defaultParserState "" xs)
- endsWithListPunct xs = case reverse xs of
- '.':_ -> True
- ')':_ -> True
- _ -> False
+ go (if inlist then avoidBadWrapsInList lst else lst)
+ where go [] = return empty
+ go (i:is) = case i of
+ (Link _ _) -> case is of
+ -- If a link is followed by another link or '[' we don't shortcut
+ (Link _ _):_ -> unshortcutable
+ Space:(Link _ _):_ -> unshortcutable
+ Space:(Str('[':_)):_ -> unshortcutable
+ Space:(RawInline _ ('[':_)):_ -> unshortcutable
+ Space:(Cite _ _):_ -> unshortcutable
+ (Cite _ _):_ -> unshortcutable
+ Str ('[':_):_ -> unshortcutable
+ (RawInline _ ('[':_)):_ -> unshortcutable
+ (RawInline _ (' ':'[':_)):_ -> unshortcutable
+ _ -> shortcutable
+ _ -> shortcutable
+ where shortcutable = liftM2 (<>) (inlineToMarkdown opts i) (go is)
+ unshortcutable = do
+ iMark <- withState (\s -> s { stRefShortcutable = False })
+ (inlineToMarkdown opts i)
+ modify (\s -> s {stRefShortcutable = True })
+ fmap (iMark <>) (go is)
+
+avoidBadWrapsInList :: [Inline] -> [Inline]
+avoidBadWrapsInList [] = []
+avoidBadWrapsInList (Space:Str ('>':cs):xs) =
+ Str (' ':'>':cs) : avoidBadWrapsInList xs
+avoidBadWrapsInList (Space:Str [c]:[])
+ | c `elem` "-*+" = Str [' ', c] : []
+avoidBadWrapsInList (Space:Str [c]:Space:xs)
+ | c `elem` "-*+" = Str [' ', c] : Space : avoidBadWrapsInList xs
+avoidBadWrapsInList (Space:Str cs:Space:xs)
+ | isOrderedListMarker cs = Str (' ':cs) : Space : avoidBadWrapsInList xs
+avoidBadWrapsInList (Space:Str cs:[])
+ | isOrderedListMarker cs = Str (' ':cs) : []
+avoidBadWrapsInList (x:xs) = x : avoidBadWrapsInList xs
+
+isOrderedListMarker :: String -> Bool
+isOrderedListMarker xs = (last xs `elem` ".)") &&
+ isRight (runParserT (anyOrderedListMarker >> eof)
+ defaultParserState "" xs)
isRight :: Either a b -> Bool
isRight (Right _) = True
@@ -873,6 +894,9 @@ inlineToMarkdown opts (Link txt (src, tit)) = do
[Str s] | escapeURI s == srcSuffix -> True
_ -> False
let useRefLinks = writerReferenceLinks opts && not useAuto
+ shortcutable <- gets stRefShortcutable
+ let useShortcutRefLinks = shortcutable &&
+ isEnabled Ext_shortcut_reference_links opts
ref <- if useRefLinks then getReference txt (src, tit) else return []
reftext <- inlineListToMarkdown opts ref
return $ if useAuto
@@ -882,7 +906,9 @@ inlineToMarkdown opts (Link txt (src, tit)) = do
else if useRefLinks
then let first = "[" <> linktext <> "]"
second = if txt == ref
- then "[]"
+ then if useShortcutRefLinks
+ then ""
+ else "[]"
else "[" <> reftext <> "]"
in first <> second
else if plain
diff --git a/tests/Tests/Writers/Markdown.hs b/tests/Tests/Writers/Markdown.hs
index c2a8f5903..dce40ddcb 100644
--- a/tests/Tests/Writers/Markdown.hs
+++ b/tests/Tests/Writers/Markdown.hs
@@ -1,4 +1,5 @@
{-# LANGUAGE OverloadedStrings #-}
+{-# OPTIONS_GHC -fno-warn-name-shadowing #-}
module Tests.Writers.Markdown (tests) where
import Test.Framework
@@ -35,4 +36,92 @@ tests = [ "indented code after list"
=: bulletList [ plain "foo" <> bulletList [ plain "bar" ],
plain "baz" ]
=?> "- foo\n - bar\n- baz\n"
- ]
+ ] ++ [shortcutLinkRefsTests]
+
+shortcutLinkRefsTests :: Test
+shortcutLinkRefsTests =
+ let infix 4 =:
+ (=:) :: (ToString a, ToPandoc a)
+ => String -> (a, String) -> Test
+ (=:) = test (writeMarkdown (def {writerReferenceLinks = True}) . toPandoc)
+ in testGroup "Shortcut reference links"
+ [ "Simple link (shortcutable)"
+ =: (para (link "/url" "title" "foo"))
+ =?> "[foo]\n\n [foo]: /url \"title\""
+ , "Followed by another link (unshortcutable)"
+ =: (para ((link "/url1" "title1" "first")
+ <> (link "/url2" "title2" "second")))
+ =?> unlines [ "[first][][second]"
+ , ""
+ , " [first]: /url1 \"title1\""
+ , " [second]: /url2 \"title2\""
+ ]
+ , "Followed by space and another link (unshortcutable)"
+ =: (para ((link "/url1" "title1" "first") <> " "
+ <> (link "/url2" "title2" "second")))
+ =?> unlines [ "[first][] [second]"
+ , ""
+ , " [first]: /url1 \"title1\""
+ , " [second]: /url2 \"title2\""
+ ]
+ , "Reference link is used multiple times (unshortcutable)"
+ =: (para ((link "/url1" "" "foo") <> (link "/url2" "" "foo")
+ <> (link "/url3" "" "foo")))
+ =?> unlines [ "[foo][][foo][1][foo][2]"
+ , ""
+ , " [foo]: /url1"
+ , " [1]: /url2"
+ , " [2]: /url3"
+ ]
+ , "Reference link is used multiple times (unshortcutable)"
+ =: (para ((link "/url1" "" "foo") <> " " <> (link "/url2" "" "foo")
+ <> " " <> (link "/url3" "" "foo")))
+ =?> unlines [ "[foo][] [foo][1] [foo][2]"
+ , ""
+ , " [foo]: /url1"
+ , " [1]: /url2"
+ , " [2]: /url3"
+ ]
+ , "Reference link is followed by text in brackets"
+ =: (para ((link "/url" "" "link") <> "[text in brackets]"))
+ =?> unlines [ "[link][][text in brackets]"
+ , ""
+ , " [link]: /url"
+ ]
+ , "Reference link is followed by space and text in brackets"
+ =: (para ((link "/url" "" "link") <> " [text in brackets]"))
+ =?> unlines [ "[link][] [text in brackets]"
+ , ""
+ , " [link]: /url"
+ ]
+ , "Reference link is followed by RawInline"
+ =: (para ((link "/url" "" "link") <> rawInline "markdown" "[rawText]"))
+ =?> unlines [ "[link][][rawText]"
+ , ""
+ , " [link]: /url"
+ ]
+ , "Reference link is followed by space and RawInline"
+ =: (para ((link "/url" "" "link") <> space <> rawInline "markdown" "[rawText]"))
+ =?> unlines [ "[link][] [rawText]"
+ , ""
+ , " [link]: /url"
+ ]
+ , "Reference link is followed by RawInline with space"
+ =: (para ((link "/url" "" "link") <> rawInline "markdown" " [rawText]"))
+ =?> unlines [ "[link][] [rawText]"
+ , ""
+ , " [link]: /url"
+ ]
+ , "Reference link is followed by citation"
+ =: (para ((link "/url" "" "link") <> cite [Citation "author" [] [] NormalCitation 0 0] (str "[@author]")))
+ =?> unlines [ "[link][][@author]"
+ , ""
+ , " [link]: /url"
+ ]
+ , "Reference link is followed by space and citation"
+ =: (para ((link "/url" "" "link") <> space <> cite [Citation "author" [] [] NormalCitation 0 0] (str "[@author]")))
+ =?> unlines [ "[link][] [@author]"
+ , ""
+ , " [link]: /url"
+ ]
+ ]