compatibility fixes for emphasis

.gitignore

@@ -1,2 +1,4 @@
 /lib/example.md
 /*.gem
+/.yardoc
+test*

lib/mmmd/blankshell.rb

@@ -367,6 +367,7 @@ module PointBlank
 
       # (see ::PointBlank::Parsing::NullParser#consume)
       def consume(line, parent = nil, lazy: false)
+        puts line.inspect if lazy
         @lazy_triggered = lazy || @lazy_triggered
         return [nil, nil] if line.match?(/\A {0,3}\Z/)
         return [nil, nil] if @closed
@@ -957,9 +958,9 @@ module PointBlank
         parts = tokens
         @valid_parsers.each do |parser|
           newparts = []
-          parts.each do |x|
+          parts.each_with_index do |x, i|
             if x.is_a? String
-              newparts.append(*parser.tokenize(x))
+              newparts.append(*parser.tokenize(x, newparts.last, parts[i + 1]))
             else
               newparts.append(x)
             end
@@ -1013,8 +1014,10 @@ module PointBlank
 
       # Tokenize a string
       # @param string [String]
+      # @param before [String, ::PointBlank::DOM::DOMObject]
+      # @param after [String, ::PointBlank::DOM::DOMObject]
       # @return [Array<Array(String, Class, Symbol), String>]
-      def self.tokenize(string)
+      def self.tokenize(string, before, after)
         [string]
       end
 
@@ -1142,7 +1145,7 @@ module PointBlank
     # Code inline parser
     class CodeInline < NullInline
       # (see ::PointBlank::Parsing::NullInline#tokenize)
-      def self.tokenize(string)
+      def self.tokenize(string, *_lookaround)
         open = {}
         iterate_tokens(string, "`") do |_before, current_text, matched|
           if matched
@@ -1182,7 +1185,7 @@ module PointBlank
     # Autolink inline parser
     class AutolinkInline < NullInline
       # (see ::PointBlank::Parsing::NullInline#tokenize)
-      def self.tokenize(string)
+      def self.tokenize(string, *_lookaround)
         iterate_tokens(string, /[<>]/) do |_before, current_text, matched|
           if matched
             if current_text.start_with?("<")
@@ -1238,11 +1241,10 @@ module PointBlank
         linkinfo = capture[-1][2]
         obj = build(capture[1..-2])
         if linkinfo[:label]
-          if (props = doc.root.properties[:linkdefs][linkinfo[:label]])
-            linkinfo = props
-          else
+          unless (props = doc.root.properties[:linkdefs][linkinfo[:label]])
             return nil
           end
+          linkinfo = props
         end
         obj.properties = linkinfo
         obj
@@ -1277,7 +1279,7 @@ module PointBlank
       end
 
       # (see ::PointBlank::Parsing::NullInline#tokenize)
-      def self.tokenize(string)
+      def self.tokenize(string, *_lookaround)
         iterate_tokens(string, /(?:!\[|\]\()/) do |_before, text, matched|
           next text[0] unless matched
           next ["![", self, :open] if text.start_with? "!["
@@ -1296,7 +1298,7 @@ module PointBlank
       end
 
       # (see ::PointBlank::Parsing::NullInline#tokenize)
-      def self.tokenize(string)
+      def self.tokenize(string, *_lookaround)
         iterate_tokens(string, /(?:\[|\][(\[])/) do |_before, text, matched|
           next text[0] unless matched
           next ["[", self, :open] if text.start_with? "["
@@ -1308,20 +1310,61 @@ module PointBlank
       end
     end
 
+    # TODO: this seems way too complicated for something that's supposed
+    # to be a goddamn emphasis markup parser. i'd blame it on commonmark's
+    # convoluted specs.
+    # (P.S: it could be possible to make this easier for implementers by
+    # making a claims system with pointers that do not modify the string
+    # while it's being parsed. however that would just move complexity from
+    # the parser into the scanner instead. and it does not resolve the
+    # problem of overlapping claims as efficiently as simply splitting text
+    # into tokens and remaining string bits.)
+
     # Emphasis and strong emphasis inline parser
     class EmphInline < NullInline
       INFIX_TOKENS = /^[^\p{S}\p{P}\p{Zs}_]_++[^\p{S}\p{P}\p{Zs}_]$/
       # (see ::PointBlank::Parsing::NullInline#tokenize)
-      def self.tokenize(string)
+      def self.tokenize(string, before, after)
+        bfrb = extract_left(before)
+        afra = extract_right(after)
         iterate_tokens(string, /(?:_++|\*++)/) do |bfr, text, matched|
           token, afr = text.match(/^(_++|\*++)(.?)/)[1..2]
-          left = left_token?(bfr[-1] || "", token, afr)
-          right = right_token?(bfr[-1] || "", token, afr)
+          bfr = bfr[-1] || bfrb || ""
+          afr = afr.empty? ? afra || "" : afr
+          left = left_token?(bfr, token, afr)
+          right = right_token?(bfr, token, afr)
           break_into_elements(token, [bfr[-1] || "", token, afr].join(''),
                               left, right, matched)
         end
       end
 
+      # Extract left-flanking token from before the tokenized string
+      # @param bfr [String, ::PointBlank::DOM::DOMObject, Array(String, Class, Symbol)]
+      # @return [String]
+      def self.extract_left(bfr)
+        case bfr
+        when String
+          bfr[-1]
+        when ::PointBlank::DOM::DOMObject
+          "."
+        when Array
+          bfr.first[-1]
+        end
+      end
+
+      # Extract right-flanking token from after the tokenized string
+      # @param afr [String, ::PointBlank::DOM::DOMObject, Array(String, Class, Symbol)]
+      # @return [String]
+      def self.extract_right(afr)
+        case afr
+        when String
+          afr[0]
+        when ::PointBlank::DOM::DOMObject
+          "."
+        when Array
+          afr.first[0]
+        end
+      end
       # Is this token, given these surrounding characters, left-flanking?
       # @param bfr [String]
       # @param token [String]
@@ -1431,7 +1474,7 @@ module PointBlank
     # Hard break
     class HardBreakInline < NullInline
       # (see ::PointBlank::Parsing::NullInline#tokenize)
-      def self.tokenize(string)
+      def self.tokenize(string, *_lookaround)
         iterate_tokens(string, /(?:  \n|\\\n)/) do |_before, token, matched|
           next ["\n", self, :close] if token.start_with?("  \n")
           next ["\n", self, :close] if matched