From e993712b2bd03e58277c239297b19a7f6467abed Mon Sep 17 00:00:00 2001
From: Christian Tietze <christian.tietze@gmail.com>
Date: Wed, 2 Aug 2017 12:57:47 +0200
Subject: [PATCH] require space after Atx heading hashes

Since `Sp` is defined as `Spacechar*`, right now a line like:

    #foo

Will be treated as a heading, which is uncommon enough for the CommonMark spec to specify as a mistake :) -- In practical terms, this makes editors with hashtags at the beginning of a line behave weirdly.
---
 pmh_grammar.leg | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pmh_grammar.leg b/pmh_grammar.leg
index a56db6f..b22ce92 100644
--- a/pmh_grammar.leg
+++ b/pmh_grammar.leg
@@ -55,7 +55,7 @@ Plain =     Inlines
 
 AtxInline = !Newline !(Sp '#'* Sp Newline) Inline
 
-AtxStart =  < ( "######" | "#####" | "####" | "###" | "##" | "#" ) >
+AtxStart =  < ( "######" | "#####" | "####" | "###" | "##" | "#" ) Spacechar >
             { $$ = elem((pmh_element_type)(pmh_H1 + (strlen(yytext) - 1))); }
 
 AtxHeading = < s:AtxStart Sp ( AtxInline )+ (Sp '#'* Sp)? Newline >