From 48c88d566d19683a7d5b63f88c8b4487234e3712 Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Mon, 20 Mar 2017 21:51:29 +0100
Subject: Add `space_in_atx_header` extension.

This is enabled by default in pandoc and GitHub markdown but not the
other flavors.

This requirse a space between the opening #'s and the header
text in ATX headers (as CommonMark does but many other implementations
do not).  This is desirable to avoid falsely capturing things ilke

    #hashtag

or

    #5

Closes #3512.
---
 src/Text/Pandoc/Extensions.hs       | 3 +++
 src/Text/Pandoc/Readers/Markdown.hs | 1 +
 2 files changed, 4 insertions(+)

(limited to 'src/Text')

diff --git a/src/Text/Pandoc/Extensions.hs b/src/Text/Pandoc/Extensions.hs
index b543d489f..54f38f4a0 100644
--- a/src/Text/Pandoc/Extensions.hs
+++ b/src/Text/Pandoc/Extensions.hs
@@ -112,6 +112,7 @@ data Extension =
     | Ext_intraword_underscores  -- ^ Treat underscore inside word as literal
     | Ext_blank_before_blockquote -- ^ Require blank line before a blockquote
     | Ext_blank_before_header     -- ^ Require blank line before a header
+    | Ext_space_in_atx_header -- ^ Require space between # and header text
     | Ext_strikeout           -- ^ Strikeout using ~~this~~ syntax
     | Ext_superscript         -- ^ Superscript using ^this^ syntax
     | Ext_subscript           -- ^ Subscript using ~this~ syntax
@@ -168,6 +169,7 @@ pandocExtensions = extensionsFromList
   , Ext_intraword_underscores
   , Ext_blank_before_blockquote
   , Ext_blank_before_header
+  , Ext_space_in_atx_header
   , Ext_strikeout
   , Ext_superscript
   , Ext_subscript
@@ -223,6 +225,7 @@ githubMarkdownExtensions = extensionsFromList
   , Ext_ascii_identifiers
   , Ext_backtick_code_blocks
   , Ext_autolink_bare_uris
+  , Ext_space_in_atx_header
   , Ext_intraword_underscores
   , Ext_strikeout
   , Ext_hard_line_breaks
diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs
index 169872391..0cc10c1d4 100644
--- a/src/Text/Pandoc/Readers/Markdown.hs
+++ b/src/Text/Pandoc/Readers/Markdown.hs
@@ -534,6 +534,7 @@ atxHeader = try $ do
   level <- atxChar >>= many1 . char >>= return . length
   notFollowedBy $ guardEnabled Ext_fancy_lists >>
                   (char '.' <|> char ')') -- this would be a list
+  guardDisabled Ext_space_in_atx_header <|> notFollowedBy nonspaceChar
   skipSpaces
   (text, raw) <- withRaw $
           trimInlinesF . mconcat <$> many (notFollowedBy atxClosing >> inline)
-- 
cgit v1.2.3