Smart dash not quite smart

According to https://daringfireball.net/projects/smartypants/:

SmartyPants can perform the following transformations:

• Straight quotes ( " and ' ) into “curly” quote HTML entities
• Backticks-style quotes (``like this'') into “curly” quote HTML entities
• Dashes (“--” and “---”) into en- and em-dash entities
• Three consecutive dots (“...”) into an ellipsis entity

This does not seem the immplementation in Haroopad. Specifically, "--" becomes the em-dash, and I do not see how to generate an en-dash.

I think the described behaviour is quite standard now—my existing MarkDown files contain such dashes and are rendered well.

So I guess Haroopad should be fixed. Agree?