From 708973a33a0ce425bb21a5ffa06fbdab465d3fb8 Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Thu, 25 May 2017 12:50:43 +0200
Subject: Added `spaced_reference_links` extension.

This is now the default for pandoc's Markdown.
It allows whitespace between the two parts of a
reference link:  e.g.

    [a] [b]

    [b]: url

This is now forbidden by default.

Closes #2602.
---
 src/Text/Pandoc/Extensions.hs       | 6 +++++-
 src/Text/Pandoc/Readers/Markdown.hs | 8 +++++---
 2 files changed, 10 insertions(+), 4 deletions(-)

(limited to 'src')

diff --git a/src/Text/Pandoc/Extensions.hs b/src/Text/Pandoc/Extensions.hs
index 374fae2c1..58e8c414d 100644
--- a/src/Text/Pandoc/Extensions.hs
+++ b/src/Text/Pandoc/Extensions.hs
@@ -137,6 +137,7 @@ data Extension =
     | Ext_shortcut_reference_links -- ^ Shortcut reference links
     | Ext_smart               -- ^ "Smart" quotes, apostrophes, ellipses, dashes
     | Ext_old_dashes          -- ^ -- = em, - before number = en
+    | Ext_spaced_reference_links -- ^ Allow space between two parts of ref link
     deriving (Show, Read, Enum, Eq, Ord, Bounded, Data, Typeable, Generic)
 
 -- | Extensions to be used with pandoc-flavored markdown.
@@ -187,7 +188,7 @@ pandocExtensions = extensionsFromList
   , Ext_smart
   ]
 
--- | Extensions to be used with github-flavored markdown.
+-- | Extensions to be used with plain text output.
 plainExtensions :: Extensions
 plainExtensions = extensionsFromList
   [ Ext_table_captions
@@ -220,6 +221,7 @@ phpMarkdownExtraExtensions = extensionsFromList
   , Ext_link_attributes
   , Ext_abbreviations
   , Ext_shortcut_reference_links
+  , Ext_spaced_reference_links
   ]
 
 -- | Extensions to be used with github-flavored markdown.
@@ -272,6 +274,7 @@ multimarkdownExtensions = extensionsFromList
   , Ext_superscript
   , Ext_subscript
   , Ext_backtick_code_blocks
+  , Ext_spaced_reference_links
   ]
 
 -- | Language extensions to be used with strict markdown.
@@ -279,6 +282,7 @@ strictExtensions :: Extensions
 strictExtensions = extensionsFromList
   [ Ext_raw_html
   , Ext_shortcut_reference_links
+  , Ext_spaced_reference_links
   ]
 
 -- | Default extensions from format-describing string.
diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs
index 11f35deb2..4fb75b344 100644
--- a/src/Text/Pandoc/Readers/Markdown.hs
+++ b/src/Text/Pandoc/Readers/Markdown.hs
@@ -1750,10 +1750,12 @@ referenceLink :: PandocMonad m
 referenceLink constructor (lab, raw) = do
   sp <- (True <$ lookAhead (char ' ')) <|> return False
   (_,raw') <- option (mempty, "") $
-      lookAhead (try (guardEnabled Ext_citations >>
-                      spnl >> normalCite >> return (mempty, "")))
+      lookAhead (try (do guardEnabled Ext_citations
+                         guardDisabled Ext_spaced_reference_links <|> spnl
+                         normalCite
+                         return (mempty, "")))
       <|>
-      try (spnl >> reference)
+      try ((guardDisabled Ext_spaced_reference_links <|> spnl) >> reference)
   when (raw' == "") $ guardEnabled Ext_shortcut_reference_links
   let labIsRef = raw' == "" || raw' == "[]"
   let key = toKey $ if labIsRef then raw else raw'
-- 
cgit v1.2.3