Update Maddy to not convert internal single underscores.

Still has problems with internal double-underscores, but at least those are less common.

Author: luciansmith

src/sbml/maddy/emphasizedparser.h

@@ -40,8 +40,10 @@ class EmphasizedParser : public LineParser
    */
   void Parse(std::string& line) override
   {
+    // Modifed from previous version, with help from
+    // https://stackoverflow.com/questions/61346949/regex-for-markdown-emphasis
     static std::regex re(
-      R"((?!.*`.*|.*<code>.*)_(?!.*`.*|.*<\/code>.*)([^_]*)_(?!.*`.*|.*<\/code>.*))"
+      R"((?!.*`.*|.*<code>.*)\b_(?![\s])(?!.*`.*|.*<\/code>.*)(.*?[^\s])_\b(?!.*`.*|.*<\/code>.*))"
     );
     static std::string replacement = "<em>$1</em>";
 

src/sbml/maddy/parser.h

@@ -59,7 +59,7 @@ class Parser
    */
   static const std::string& version()
   {
-    static const std::string v = "1.4.0";
+    static const std::string v = "1.5.0";
     return v;
   }
 

src/sbml/maddy/strongparser.h

@@ -40,6 +40,23 @@ class StrongParser : public LineParser
    */
   void Parse(std::string& line) override
   {
+    // This version of the regex is changed exactly the same way
+    // that the regex for the emphasized parser was changed, and
+    // it then passes all the 'disabled' tests in the 'strong parser'
+    // test, but then it fails general parsing.  For some reason,
+    // "__text__" translates "<i></i>text<i></i>" even though there
+    // are no word boundaries at the correct places.  It's weird!
+
+    // static std::vector<std::regex> res{
+    //   std::regex{
+    //     R"((?!.*`.*|.*<code>.*)\b\*\*(?![\s])(?!.*`.*|.*<\/code>.*)"
+    //      "(.*?[^\s])\*\*\b(?!.*`.*|.*<\/code>.*))"
+    //   },
+    //   std::regex{
+    //     R"((?!.*`.*|.*<code>.*)\b__(?![\s])(?!.*`.*|.*<\/code>.*)"
+    //      "(.*?[^\s])__\b(?!.*`.*|.*<\/code>.*))"
+    //   }
+    // };
     static std::vector<std::regex> res{
       std::regex{
         R"((?!.*`.*|.*<code>.*)\*\*(?!.*`.*|.*<\/code>.*)([^\*\*]*)\*\*(?!.*`.*|.*<\/code>.*))"