code: function handleText(stream, mdState) {
      var match;
      if (stream.match(/^\w+:\/\/\S+/)) {
        return 'linkhref';
      }
      if (stream.match(/^[^\[*\\<>` _][^\[*\\<>` ]*[^\[*\\<>` _]/)) {
        return mdMode.getType(mdState);
      }
      if (match = stream.match(/^[^\[*\\<>` ]+/)) {
        var word = match[0];
        if (word[0] === '_' && word[word.length-1] === '_') {
          stream.backUp(word.length);
          return undefined;
        }
        return mdMode.getType(mdState);
      }
      if (stream.eatSpace()) {
        return null;
      }
    }
docs: custom handleText to prevent emphasis in the middle of a word and add autolinking