avoid some recursion vor better compatibility and performance

diff --git a/markdown.awk b/markdown.awk
index 26fc11b350d12e3aa21a5ac3713183b0a3420847..d1c8b5b6c2bf571593810653f714ad4ba79a3c43 100755 (executable)
--- a/markdown.awk
+++ b/markdown.awk
@@ -121,217 +121,259 @@ function URL ( text, sharp ) {
   return text;
 }
 
-function inline( line, LOCAL, len, text, code, href, guard ) {
-  if ( line ~ /^$/ ) {  # Recursion End
-    return "";
-
-  # omit processing of escaped characters
-  } else if ( line ~ /^\\./) {
-    return HTML(substr(line, 2, 1)) inline( substr(line, 3) );
-
-  # hard brakes
-  } else if ( match(line, /^  \n/) ) {
-    return "<br>\n" inline( substr(line, RLENGTH + 1) );
-
-  #  ``code spans``
-  } else if ( match( line, /^`+/) ) {
-    len = RLENGTH
-    guard = substr( line, 1, len )
-    if ( match(line, guard ".*" guard) ) {
-      code = substr( line, len + 1, match( substr(line, len + 1), guard ) - 1)
-      len = 2 * length(guard) + length(code)
-      #  strip single surrounding white spaces
-      gsub( /^ | $/, "", code)
-      #  escape HTML within code span
-      gsub( /&/, "\\&amp;", code ); gsub( /</, "\\&lt;", code ); gsub( />/, "\\&gt;", code );
-      return "<code>" code "</code>" inline( substr( line, len + 1 ) )
-    }
-
-  # Macros
-  } else if ( match( line, /^<<([^>]|>[^>])+>>/ ) ) {
-    len = RLENGTH;
-    return "<code class=\"macro\">" HTML( substr( line, 3, len - 4 ) ) "</code>" inline(substr(line, len + 1));
-
-  # Wiki style links
-  } else if ( match( line, /^\[\[([^]|]+)(\|[^]]+)?\]\]/) ) {
-    len = RLENGTH; href = text = substr(line, 1, len);
-    sub(/^\[\[/, "", href); sub(/(\|([^]]+))?\]\].*$/, "", href);
-    sub(/^\[\[([^]|]+)/, "", text); sub(/\]\].*$/, "", text); sub(/^\|/, "", text);
-    # sub(/^\[\[([^]|]+)(\|([^]]+))?\]\]/, "\\1", href );
-    # sub(/^\[\[([^]|]+)(\|([^]]+))?\]\]/, "\\3", text );
-    if ( ! text ) text = href;
-    return "<a href=\"" HTML(href) "\">" HTML(text) "</a>" inline( substr( line, len + 1) );
-
-  #  quick links ("automatic links" in md doc)
-  } else if ( match( line, /^<[a-zA-Z]+:\/\/([-\.[:alnum:]]+)(:[0-9]*)?(\/[^>]*)?>/ ) ) {
-    len = RLENGTH;
-    href = HTML( substr( line, 2, len - 2) );
-    return "<a href=\"" href "\">" href "</a>" inline( substr( line, len + 1) );
-
-  # quick link email
-  } else if ( match( line, /^<[a-zA-Z0-9.!#$%&'\''*+\/=?^_`{|}~-]+@[a-zA-Z0-9]([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(\.[a-zA-Z0-9]([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*>/ ) ) {
-    len = RLENGTH;
-    href = HTML( substr( line, 2, len - 2) );
-    return "<a href=\"mailto:" href "\">" href "</a>" inline( substr( line, len + 1) );
-
-  # Verbatim inline HTML
-  } else if ( AllowHTML && match( line, /^(<!--([^-]|-[^-]|--[^>])*-->|<\?([^\?]|\?[^>])*\?>|<![A-Z][^>]*>|<!\[CDATA\[([^\]]|\][^\]]|\]\][^>])*\]\]>|<\/[A-Za-z][A-Za-z0-9-]*[[:space:]]*>|<[A-Za-z][A-Za-z0-9-]*([[:space:]]+[A-Za-z_:][A-Za-z0-9_\.:-]*([[:space:]]*=[[:space:]]*([[:space:]"'=<>`]+|"[^"]*"|'[^']*'))?)*[[:space:]]*\/?>)/) ) {
-    len = RLENGTH;
-    return substr( line, 1, len) inline(substr(line, len + 1));
-
-  # inline links
-  } else if ( match(line, "^" lii "\\([\n\t ]*" lid "([\n\t ]+" lit ")?[\n\t ]*\\)") ) {
-    len = RLENGTH;
-    text = href = title = substr( line, 1, len);
-    sub("^\\[", "", text); sub("\\]\\([\n\t ]*" lid "([\n\t ]+" lit ")?[\n\t ]*\\)$", "", text);
-    sub("^" lii "\\([\n\t ]*", "", href); sub("([\n\t ]+" lit ")?[\n\t ]*\\)$", "", href);
-    sub("^" lii "\\([\n\t ]*" lid, "", title); sub("[\n\t ]*\\)$", "", title); sub("^[\n\t ]+", "", title);
-
-    if ( match(href, /^<.*>$/) ) { sub(/^</, "", href); sub(/>$/, "", href); }
-         if ( match(title, /^".*"$/) ) { sub(/^"/, "", title); sub(/"$/, "", title); }
-    else if ( match(title, /^'.*'$/) ) { sub(/^'/, "", title); sub(/'$/, "", title); }
-    else if ( match(title, /^\(.*\)$/) ) { sub(/^\(/, "", title); sub(/\)$/, "", title); }
-
-    gsub(/\\/, "", href); gsub(/\\/, "", title); gsub(/[\n\t]+/, " ", title);
-
-    return "<a href=\"" HTML(href) "\"" (title?" title=\"" HTML(title) "\"":"") ">" \
-           inline( text ) "</a>" inline( substr( line, len + 1) );
-
-  # reference style links
-  } else if ( match(line, /^\[([^]]+)\] ?\[([^]]*)\]/ ) ) {
-    len = RLENGTH; text = id = substr(line, 1, len);
-    sub(/\n.*$/, "", text); sub(/^\[/, "", text); sub(/\] ?\[([^\n]*)\].*$/, "", text);
-    sub(/\n.*$/, "",   id); sub(/^\[([^]]+)\] ?\[/, "",   id); sub(/\].*$/, "",   id);
-    # text = gensub(/^\[([^\n]+)\] ?\[([^\n]*)\].*/, "\\1", 1, text );
-    # id = gensub(/^\[([^\n]+)\] ?\[([^\n]*)\].*/, "\\2", 1,   id );
-    if ( ! id ) id = text;
-    if ( rl_href[id] && rl_title[id] ) {
-      return "<a href=\"" HTML(rl_href[id]) "\" title=\"" HTML(rl_title[id]) "\">" inline(text) "</a>" inline( substr( line, len + 1) );
-    } else if ( rl_href[id] ) {
-      return "<a href=\"" HTML(rl_href[id]) "\">" inline(text) "</a>" inline( substr( line, len + 1) );
-    } else {
-      return "" HTML(substr(line, 1, len)) inline( substr(line, len + 1) );
-    }
-
-  # inline images
-  } else if ( match(line, "^!" lix "\\([\n\t ]*" lid "([\n\t ]+" lit ")?[\n\t ]*\\)(\\{[a-zA-Z \t-]*\\})?") ) {
-    len = RLENGTH; text = href = title = attrib = substr( line, 1, len);
-
-    sub("^!\\[", "", text);
-    sub("\\]\\([\n\t ]*" lid "([\n\t ]+" lit ")?[\n\t ]*\\)(\\{[a-zA-Z \t-]*\\})?$", "", text);
-
-    sub("^!" lix "\\([\n\t ]*", "", href);
-    sub("([\n\t ]+" lit ")?[\n\t ]*\\)(\\{[a-zA-Z \t-]*\\})?$", "", href);
-
-    sub("^!" lix "\\([\n\t ]*" lid, "", title);
-    sub("[\n\t ]*\\)(\\{[a-zA-Z \t-]*\\})?$", "", title);
-    sub("^[\n\t ]+", "", title);
+function inline( line, LOCAL, len, text, code, href, guard, ret ) {
+  ret = "";
+  while (line !~ /^$/) {
+    # omit processing of escaped characters
+    if ( line ~ /^\\./) {
+      ret = ret HTML(substr(line, 2, 1)); line = substr(line, 3);
+      continue;
+
+    # hard brakes
+    } else if ( match(line, /^  \n/) ) {
+      ret = ret "<br>\n"; line = substr(line, RLENGTH + 1);
+      continue;
+
+    #  ``code spans``
+    } else if ( match( line, /^`+/) ) {
+      len = RLENGTH
+      guard = substr( line, 1, len )
+      if ( match(line, guard ".*" guard) ) {
+        code = substr( line, len + 1, match( substr(line, len + 1), guard ) - 1)
+        len = 2 * length(guard) + length(code)
+        #  strip single surrounding white spaces
+        gsub( /^ | $/, "", code)
+        #  escape HTML within code span
+        gsub( /&/, "\\&amp;", code ); gsub( /</, "\\&lt;", code ); gsub( />/, "\\&gt;", code );
+        ret = ret "<code>" code "</code>"; line = substr( line, len + 1 );
+        continue;
+      }
 
-    sub("^!" lix "\\([\n\t ]*" lid "([\n\t ]+" lit ")?[\n\t ]*\\)", "", attrib);
-    sub(/^\{[ \t]*/, "", attrib); sub(/[ \t]*\}$/, "", attrib); gsub(/[ \t]+/, " ", attrib);
+    # Macros
+    } else if ( match( line, /^<<([^>]|>[^>])+>>/ ) ) {
+      len = RLENGTH;
+      ret = ret "<code class=\"macro\">" HTML( substr( line, 3, len - 4 ) ) "</code>"; line = substr(line, len + 1);
+      continue;
+
+    # Wiki style links
+    } else if ( match( line, /^\[\[([^]|]+)(\|[^]]+)?\]\]/) ) {
+      len = RLENGTH; href = text = substr(line, 1, len);
+      sub(/^\[\[/, "", href); sub(/(\|([^]]+))?\]\].*$/, "", href);
+      sub(/^\[\[([^]|]+)/, "", text); sub(/\]\].*$/, "", text); sub(/^\|/, "", text);
+      # sub(/^\[\[([^]|]+)(\|([^]]+))?\]\]/, "\\1", href );
+      # sub(/^\[\[([^]|]+)(\|([^]]+))?\]\]/, "\\3", text );
+      if ( ! text ) text = href;
+      ret = ret "<a href=\"" HTML(href) "\">" HTML(text) "</a>"; line = substr( line, len + 1);
+      continue;
+
+    #  quick links ("automatic links" in md doc)
+    } else if ( match( line, /^<[a-zA-Z]+:\/\/([-\.[:alnum:]]+)(:[0-9]*)?(\/[^>]*)?>/ ) ) {
+      len = RLENGTH;
+      href = HTML( substr( line, 2, len - 2) );
+      ret = ret "<a href=\"" href "\">" href "</a>"; line = substr( line, len + 1);
+      continue;
+
+    # quick link email
+    # } else if ( match( line, /^<[a-zA-Z0-9.!#$%&'\''*+\/=?^_`{|}~-]+@[a-zA-Z0-9]([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(\.[a-zA-Z0-9]([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*>/ ) ) {
+    } else if ( match( line, /^<[a-zA-Z0-9.!#$%&'\''*+\/=?^_`{|}~-]+@[a-zA-Z0-9]([a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9])?(\.[a-zA-Z0-9]([a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9-]?[a-zA-Z0-9])?)*>/ ) ) {
+      len = RLENGTH;
+      href = HTML( substr( line, 2, len - 2) );
+      ret = ret "<a href=\"mailto:" href "\">" href "</a>"; line = substr( line, len + 1);
+      continue;
+
+    # Verbatim inline HTML
+    } else if ( AllowHTML && match( line, /^(<!--([^-]|-[^-]|--[^>])*-->|<\?([^\?]|\?[^>])*\?>|<![A-Z][^>]*>|<!\[CDATA\[([^\]]|\][^\]]|\]\][^>])*\]\]>|<\/[A-Za-z][A-Za-z0-9-]*[[:space:]]*>|<[A-Za-z][A-Za-z0-9-]*([[:space:]]+[A-Za-z_:][A-Za-z0-9_\.:-]*([[:space:]]*=[[:space:]]*([[:space:]"'=<>`]+|"[^"]*"|'[^']*'))?)*[[:space:]]*\/?>)/) ) {
+      len = RLENGTH;
+      ret = ret substr( line, 1, len); line =substr(line, len + 1);
+      continue;
+
+    # inline links
+    } else if ( match(line, "^" lii "\\([\n\t ]*" lid "([\n\t ]+" lit ")?[\n\t ]*\\)") ) {
+      len = RLENGTH;
+      text = href = title = substr( line, 1, len);
+      sub("^\\[", "", text); sub("\\]\\([\n\t ]*" lid "([\n\t ]+" lit ")?[\n\t ]*\\)$", "", text);
+      sub("^" lii "\\([\n\t ]*", "", href); sub("([\n\t ]+" lit ")?[\n\t ]*\\)$", "", href);
+      sub("^" lii "\\([\n\t ]*" lid, "", title); sub("[\n\t ]*\\)$", "", title); sub("^[\n\t ]+", "", title);
+
+      if ( match(href, /^<.*>$/) ) { sub(/^</, "", href); sub(/>$/, "", href); }
+           if ( match(title, /^".*"$/) ) { sub(/^"/, "", title); sub(/"$/, "", title); }
+      else if ( match(title, /^'.*'$/) ) { sub(/^'/, "", title); sub(/'$/, "", title); }
+      else if ( match(title, /^\(.*\)$/) ) { sub(/^\(/, "", title); sub(/\)$/, "", title); }
+
+      gsub(/\\/, "", href); gsub(/\\/, "", title); gsub(/[\n\t]+/, " ", title);
+
+      ret = ret "<a href=\"" HTML(href) "\"" (title?" title=\"" HTML(title) "\"":"") ">" \
+             inline( text ) "</a>";
+      line = substr( line, len + 1);
+      continue;
+
+    # reference style links
+    } else if ( match(line, /^\[([^]]+)\] ?\[([^]]*)\]/ ) ) {
+      len = RLENGTH; text = id = substr(line, 1, len);
+      sub(/\n.*$/, "", text); sub(/^\[/, "", text); sub(/\] ?\[([^\n]*)\].*$/, "", text);
+      sub(/\n.*$/, "",   id); sub(/^\[([^]]+)\] ?\[/, "",   id); sub(/\].*$/, "",   id);
+      # text = gensub(/^\[([^\n]+)\] ?\[([^\n]*)\].*/, "\\1", 1, text );
+      # id = gensub(/^\[([^\n]+)\] ?\[([^\n]*)\].*/, "\\2", 1,   id );
+      if ( ! id ) id = text;
+
+      if ( rl_href[id] && rl_title[id] ) {
+        ret = ret "<a href=\"" HTML(rl_href[id]) "\" title=\"" HTML(rl_title[id]) "\">" inline(text) "</a>";
+        line = substr( line, len + 1);
+        continue;
+
+      } else if ( rl_href[id] ) {
+        ret = ret "<a href=\"" HTML(rl_href[id]) "\">" inline(text) "</a>"; line = substr( line, len + 1);
+        continue;
+
+      } else {
+        ret = ret "" HTML(substr(line, 1, len)); line = substr(line, len + 1);
+        continue;
+      }
 
-    if ( match(href, /^<.*>$/) ) { sub(/^</, "", href); sub(/>$/, "", href); }
-         if ( match(title, /^".*"$/) ) { sub(/^"/, "", title); sub(/"$/, "", title); }
-    else if ( match(title, /^'.*'$/) ) { sub(/^'/, "", title); sub(/'$/, "", title); }
-    else if ( match(title, /^\(.*\)$/) ) { sub(/^\(/, "", title); sub(/\)$/, "", title); }
+    # inline images
+    } else if ( match(line, "^!" lix "\\([\n\t ]*" lid "([\n\t ]+" lit ")?[\n\t ]*\\)(\\{[a-zA-Z \t-]*\\})?") ) {
+      len = RLENGTH; text = href = title = attrib = substr( line, 1, len);
+
+      sub("^!\\[", "", text);
+      sub("\\]\\([\n\t ]*" lid "([\n\t ]+" lit ")?[\n\t ]*\\)(\\{[a-zA-Z \t-]*\\})?$", "", text);
+
+      sub("^!" lix "\\([\n\t ]*", "", href);
+      sub("([\n\t ]+" lit ")?[\n\t ]*\\)(\\{[a-zA-Z \t-]*\\})?$", "", href);
+
+      sub("^!" lix "\\([\n\t ]*" lid, "", title);
+      sub("[\n\t ]*\\)(\\{[a-zA-Z \t-]*\\})?$", "", title);
+      sub("^[\n\t ]+", "", title);
+
+      sub("^!" lix "\\([\n\t ]*" lid "([\n\t ]+" lit ")?[\n\t ]*\\)", "", attrib);
+      sub(/^\{[ \t]*/, "", attrib); sub(/[ \t]*\}$/, "", attrib); gsub(/[ \t]+/, " ", attrib);
+
+      if ( match(href, /^<.*>$/) ) { sub(/^</, "", href); sub(/>$/, "", href); }
+           if ( match(title, /^".*"$/) ) { sub(/^"/, "", title); sub(/"$/, "", title); }
+      else if ( match(title, /^'.*'$/) ) { sub(/^'/, "", title); sub(/'$/, "", title); }
+      else if ( match(title, /^\(.*\)$/) ) { sub(/^\(/, "", title); sub(/\)$/, "", title); }
+
+      gsub(/^[\t ]+$/, "", text); gsub(/\\/, "", href);
+      gsub(/\\/, "", title); gsub(/[\n\t]+/, " ", title);
+
+      ret = ret "<img src=\"" HTML(href) "\" alt=\"" HTML(text?text:title?title:href) "\"" \
+             (title?" title=\"" HTML(title) "\"":"") (attrib?" class=\"" HTML(attrib) "\"":"") \
+             ">";
+      line = substr( line, len + 1);
+      continue;
+
+    # reference style images
+    } else if ( match(line, /^!\[([^]]*)\] ?\[([^]]*)\]/ ) ) {
+      len = RLENGTH; text = id = substr(line, 1, len);
+      sub(/\n.*$/, "", text); sub(/^!\[/, "", text); sub(/\] ?\[([^\n]*)\].*$/, "", text);
+      sub(/\n.*$/, "",   id); sub(/^!\[([^]]+)\] ?\[/, "",   id); sub(/\].*$/, "",   id);
+      # text = gensub(/^!\[([^\n]*)\] ?\[([^\n]*)\].*/, "\\1", 1, substr(line, 1, len) );
+      #   id = gensub(/^!\[([^\n]*)\] ?\[([^\n]*)\].*/, "\\2", 1, substr(line, 1, len) );
+      if ( ! id ) id = text;
+      if ( rl_href[id] && rl_title[id] ) {
+        ret = ret "<img src=\"" HTML(rl_href[id]) "\" alt=\"" HTML(text) "\" title=\"" HTML(rl_title[id]) "\">";
+        line = substr( line, len + 1);
+        continue;
+
+      } else if ( rl_href[id] ) {
+        ret = ret "<img src=\"" HTML(rl_href[id]) "\" alt=\"" HTML(text) "\">";
+        line = substr( line, len + 1);
+        continue;
+
+      } else {
+        ret = ret "" HTML(substr(line, 1, len)); line = substr(line, len + 1);
+        continue;
+      }
 
-    gsub(/^[\t ]+$/, "", text); gsub(/\\/, "", href);
-    gsub(/\\/, "", title); gsub(/[\n\t]+/, " ", title);
-
-    return "<img src=\"" HTML(href) "\" alt=\"" HTML(text?text:title?title:href) "\"" \
-           (title?" title=\"" HTML(title) "\"":"") (attrib?" class=\"" HTML(attrib) "\"":"") \
-           ">" inline( substr( line, len + 1) );
-
-  # reference style images
-  } else if ( match(line, /^!\[([^]]*)\] ?\[([^]]*)\]/ ) ) {
-    len = RLENGTH; text = id = substr(line, 1, len);
-    sub(/\n.*$/, "", text); sub(/^!\[/, "", text); sub(/\] ?\[([^\n]*)\].*$/, "", text);
-    sub(/\n.*$/, "",   id); sub(/^!\[([^]]+)\] ?\[/, "",   id); sub(/\].*$/, "",   id);
-    # text = gensub(/^!\[([^\n]*)\] ?\[([^\n]*)\].*/, "\\1", 1, substr(line, 1, len) );
-    #   id = gensub(/^!\[([^\n]*)\] ?\[([^\n]*)\].*/, "\\2", 1, substr(line, 1, len) );
-    if ( ! id ) id = text;
-    if ( rl_href[id] && rl_title[id] ) {
-      return "<img src=\"" HTML(rl_href[id]) "\" alt=\"" HTML(text) "\" title=\"" HTML(rl_title[id]) "\">" \
-             inline( substr( line, len + 1) );
-    } else if ( rl_href[id] ) {
-      return "<img src=\"" HTML(rl_href[id]) "\" alt=\"" HTML(text) "\">" \
-             inline( substr( line, len + 1) );
+    #  ~~strikeout~~ (pandoc)
+    } else if ( match(line, /^~~([[:graph:]]|[[:graph:]]([^~]|~[^~])*[[:graph:]])~~/) ) {
+      len = RLENGTH;
+      ret = ret "<del>" inline( substr( line, 3, len - 4 ) ) "</del>"; line = substr( line, len + 1 );
+      continue;
+
+    #  ^superscript^ (pandoc)
+    } else if ( match(line, /^\^([^[:space:]^]|\\[ ^])+\^/) ) {
+      len = RLENGTH;
+      ret = ret "<sup>" inline( substr( line, 2, len - 2 ) ) "</sup>"; line = substr( line, len + 1 );
+      continue;
+
+    #  ~subscript~ (pandoc)
+    } else if ( match(line, /^~([^[:space:]~]|\\[ ~])+~/) ) {
+      len = RLENGTH;
+      ret = ret "<sub>" inline( substr( line, 2, len - 2 ) ) "</sub>"; line = substr( line, len + 1 );
+      continue;
+
+    # ignore embedded underscores (pandoc, php md)
+    } else if ( match(line, "^[[:alnum:]](__|_)") ) {
+      ret = ret HTML(substr( line, 1, RLENGTH)); line = substr(line, RLENGTH + 1);
+      continue;
+
+    #  __strong__$
+    } else if ( match(line, "^__(([^_[:space:]]|" ieu ")|([^_[:space:]]|" ieu ")(" nu "|" ieu ")*([^_[:space:]]|" ieu "))__$") ) {
+      len = RLENGTH;
+      ret = ret "<strong>" inline( substr( line, 3, len - 4 ) ) "</strong>"; line = substr( line, len + 1 );
+      continue;
+
+    #  __strong__
+    } else if ( match(line, "^__(([^_[:space:]]|" ieu ")|([^_[:space:]]|" ieu ")(" nu "|" ieu ")*([^_[:space:]]|" ieu "))__[[:space:][:punct:]]") ) {
+      len = RLENGTH;
+      ret = ret "<strong>" inline( substr( line, 3, len - 5 ) ) "</strong>"; line = substr( line, len);
+      continue;
+
+    #  **strong**
+    } else if ( match(line, "^\\*\\*(([^\\*[:space:]]|" iea ")|([^\\*[:space:]]|" iea ")(" na "|" iea ")*([^\\*[:space:]]|" iea "))\\*\\*") ) {
+      len = RLENGTH;
+      ret = ret "<strong>" inline( substr( line, 3, len - 4 ) ) "</strong>"; line = substr( line, len + 1 );
+      continue;
+
+    #  _em_$
+    } else if ( match(line, "^_(([^_[:space:]]|" isu ")|([^_[:space:]]|" isu ")(" nu "|" isu ")*([^_[:space:]]|" isu "))_$") ) {
+      len = RLENGTH;
+      ret = ret "<em>" inline( substr( line, 2, len - 2 ) ) "</em>"; line = substr( line, len + 1 );
+      continue;
+
+    #  _em_
+    } else if ( match(line, "^_(([^_[:space:]]|" isu ")|([^_[:space:]]|" isu ")(" nu "|" isu ")*([^_[:space:]]|" isu "))_[[:space:][:punct:]]") ) {
+      len = RLENGTH;
+      ret = ret "<em>" inline( substr( line, 2, len - 3 ) ) "</em>"; line = substr( line, len );
+      continue;
+
+    #  *em*
+    } else if ( match(line, "^\\*(([^\\*[:space:]]|" isa ")|([^\\*[:space:]]|" isa ")(" na "|" isa ")*([^\\*[:space:]]|" isa "))\\*") ) {
+      len = RLENGTH;
+      ret = ret "<em>" inline( substr( line, 2, len - 2 ) ) "</em>"; line = substr( line, len + 1 );
+      continue;
+
+    # Literal HTML entities
+    # } else if ( match( line, /^&([a-zA-Z]{2,32}|#[0-9]{1,7}|#[xX][0-9a-fA-F]{1,6});/) ) {
+    # mawk does not support repitition ranges
+    } else if ( match( line, /^&([a-zA-Z][a-zA-Z][a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?|#[0-9][0-9]?[0-9]?[0-9]?[0-9]?[0-9]?[0-9]?|#[xX][0-9a-fA-F][0-9a-fA-F]?[0-9a-fA-F]?[0-9a-fA-F]?[0-9a-fA-F]?[0-9a-fA-F]?);/) ) {
+      len = RLENGTH;
+      ret = ret substr( line, 1, len ); line = substr(line, len + 1);
+      continue;
+
+    # Arrows
+    } else if ( line ~ /^-->( |$)/) {  # ignore multidash-arrow
+      ret = ret "--&gt;"; line = substr(line, 4);
+      continue;
+    } else if ( line ~ /^<-( |$)/) {
+      ret = ret "&larr;"; line = substr(line, 3);
+      continue;
+    } else if ( line ~ /^->( |$)/) {
+      ret = ret "&rarr;"; line = substr(line, 3);
+      continue;
+
+    # Escape lone HTML character
+    } else if ( match( line, /^[&<>"']/) ) {
+      ret = ret HTML(substr(line, 1, 1)); line = substr(line, 2);
+      continue;
+
+    #  continue walk over string
     } else {
-      return "" HTML(substr(line, 1, len)) inline( substr(line, len + 1) );
+      ret = ret substr(line, 1, 1); line = substr(line, 2);
+      continue;
     }
-
-  #  ~~strikeout~~ (pandoc)
-  } else if ( match(line, /^~~([[:graph:]]|[[:graph:]]([^~]|~[^~])*[[:graph:]])~~/) ) {
-    len = RLENGTH;
-    return "<del>" inline( substr( line, 3, len - 4 ) ) "</del>" inline( substr( line, len + 1 ) );
-
-  #  ^superscript^ (pandoc)
-  } else if ( match(line, /^\^([^[:space:]^]|\\[ ^])+\^/) ) {
-    len = RLENGTH;
-    return "<sup>" inline( substr( line, 2, len - 2 ) ) "</sup>" inline( substr( line, len + 1 ) );
-
-  #  ~subscript~ (pandoc)
-  } else if ( match(line, /^~([^[:space:]~]|\\[ ~])+~/) ) {
-    len = RLENGTH;
-    return "<sub>" inline( substr( line, 2, len - 2 ) ) "</sub>" inline( substr( line, len + 1 ) );
-
-  # ignore embedded underscores (pandoc, php md)
-  } else if ( match(line, "^[[:alnum:]](__|_)") ) {
-    return HTML(substr( line, 1, RLENGTH)) inline( substr(line, RLENGTH + 1) );
-
-  #  __strong__$
-  } else if ( match(line, "^__(([^_[:space:]]|" ieu ")|([^_[:space:]]|" ieu ")(" nu "|" ieu ")*([^_[:space:]]|" ieu "))__$") ) {
-    len = RLENGTH;
-    return "<strong>" inline( substr( line, 3, len - 4 ) ) "</strong>" inline( substr( line, len + 1 ) );
-
-  #  __strong__
-  } else if ( match(line, "^__(([^_[:space:]]|" ieu ")|([^_[:space:]]|" ieu ")(" nu "|" ieu ")*([^_[:space:]]|" ieu "))__[[:space:][:punct:]]") ) {
-    len = RLENGTH;
-    return "<strong>" inline( substr( line, 3, len - 5 ) ) "</strong>" inline( substr( line, len) );
-
-  #  **strong**
-  } else if ( match(line, "^\\*\\*(([^\\*[:space:]]|" iea ")|([^\\*[:space:]]|" iea ")(" na "|" iea ")*([^\\*[:space:]]|" iea "))\\*\\*") ) {
-    len = RLENGTH;
-    return "<strong>" inline( substr( line, 3, len - 4 ) ) "</strong>" inline( substr( line, len + 1 ) );
-
-  #  _em_$
-  } else if ( match(line, "^_(([^_[:space:]]|" isu ")|([^_[:space:]]|" isu ")(" nu "|" isu ")*([^_[:space:]]|" isu "))_$") ) {
-    len = RLENGTH;
-    return "<em>" inline( substr( line, 2, len - 2 ) ) "</em>" inline( substr( line, len + 1 ) );
-
-  #  _em_
-  } else if ( match(line, "^_(([^_[:space:]]|" isu ")|([^_[:space:]]|" isu ")(" nu "|" isu ")*([^_[:space:]]|" isu "))_[[:space:][:punct:]]") ) {
-    len = RLENGTH;
-    return "<em>" inline( substr( line, 2, len - 3 ) ) "</em>" inline( substr( line, len ) );
-
-  #  *em*
-  } else if ( match(line, "^\\*(([^\\*[:space:]]|" isa ")|([^\\*[:space:]]|" isa ")(" na "|" isa ")*([^\\*[:space:]]|" isa "))\\*") ) {
-    len = RLENGTH;
-    return "<em>" inline( substr( line, 2, len - 2 ) ) "</em>" inline( substr( line, len + 1 ) );
-
-  # Literal HTML entities
-  # } else if ( match( line, /^&([a-zA-Z]{2,32}|#[0-9]{1,7}|#[xX][0-9a-fA-F]{1,6});/) ) {
-  # mawk does not support repitition ranges
-  } else if ( match( line, /^&([a-zA-Z][a-zA-Z][a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?[a-zA-Z]?|#[0-9][0-9]?[0-9]?[0-9]?[0-9]?[0-9]?[0-9]?|#[xX][0-9a-fA-F][0-9a-fA-F]?[0-9a-fA-F]?[0-9a-fA-F]?[0-9a-fA-F]?[0-9a-fA-F]?);/) ) {
-    len = RLENGTH;
-    return substr( line, 1, len ) inline(substr(line, len + 1));
-
-  # Arrows
-  } else if ( line ~ /^-->( |$)/) {  # ignore multidash-arrow
-    return "--&gt;" inline( substr(line, 4) );
-  } else if ( line ~ /^<-( |$)/) {
-    return "&larr;" inline( substr(line, 3) );
-  } else if ( line ~ /^->( |$)/) {
-    return "&rarr;" inline( substr(line, 3) );
-
-  # Escape lone HTML character
-  } else if ( match( line, /^[&<>"']/) ) {
-    return HTML(substr(line, 1, 1)) inline(substr(line, 2));
-
-  #  continue walk over string
-  } else {
-    return substr(line, 1, 1) inline( substr(line, 2) );
   }
+  return ret;
 }
 
 function headline( hlvl, htxt, attrib, LOCAL, sec, n, HL) {
@@ -364,14 +406,14 @@ function _nblock( block, LOCAL, sec, n ) {
   for ( n = blvl + 1; n in BL; n++) { delete BL[n]; }
 
   block = _block( block );
-  match(hstack, /([0-9]+( [0-9]+){5})$/); split( substr(hstack, RSTART),  HL);
+  match(hstack, /([0-9]+( [0-9]+)( [0-9]+)?( [0-9]+)?( [0-9]+)?( [0-9]+)?)$/); split( substr(hstack, RSTART),  HL);
   sec = ""; for ( n = 1; n <= 6; n++ ) { sec = sec (HL[n]?"</section>":""); }
 
-  sub("( +[0-9]+){6} *$", "", hstack); blvl--;
+  sub("( +[0-9]+)( +[0-9]+)?( +[0-9]+)?( +[0-9]+)?( +[0-9]+)?( +[0-9]+)? *$", "", hstack); blvl--;
   return block sec;
 }
 
-function _block( block, LOCAL, st, len, text, title, attrib, href, guard, code, indent, list ) {
+function _block( block, LOCAL, st, len, text, title, attrib, href, guard, code, indent, list, tmp ) {
   gsub( "(^\n+|\n+$)", "", block );
 
   if ( block == "" ) {