Welcome to the Lounge

Greg Utas wrote:

Ah yes, the 90-10 rule.

M.D.V.

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.

PIEBALDconsult wrote:

(not that any HTML is truly good)

lineComment<skipped>='\/\/[^\n]*';
blockComment<skipped,blockEnd="*/">="/*";

size_t Lexer::NextPos(size_t pos) const
{
   //  Find the next character to be parsed.
   //
   while(pos < size_)
   {
      auto c = source_->at(pos);

      switch(c)
      {
      case SPACE:
      case CRLF:
      case TAB:
         //
         //  Skip these.
         //
         ++pos;
         break;

      case '/':
         //
         //  See if this begins a comment (// or /*).
         //
         if(++pos >= size_) return string::npos;

         switch(source_->at(pos))
         {
         case '/':
            //
            //  This is a // comment.  Continue on the next line.
            //
            pos = source_->find(CRLF, pos);
            if(pos == string::npos) return pos;
            ++pos;
            break;

         case '*':
            //
            //  This is a /* comment.  Continue where it ends.
            //
            if(++pos >= size_) return string::npos;
            pos = source_->find(COMMENT_END_STR, pos);
            if(pos == string::npos) return string::npos;
            pos += 2;
            break;

         default:
            //
            //  The / did not introduce a comment, so it is the next
            //  character of interest.
            //
            return --pos;
         }
         break;

      case BACKSLASH:
         //
         //  See if this is a continuation of the current line.
         //
         if(++pos >= size_) return string::npos;
         if(source_->at(pos) != CRLF) return pos - 1;
         ++pos;
         break;

      default:
         return pos;
      }
   }

   return string::npos;
}