Requested here:

"The edit page text editor wikEd has a wikicode syntax highlighting function, that does "[h]ighlighting of different types of dash and blank characters"(https://en.wikipedia.org/wiki/User:Cacycle/wikEd#Full_features). This function marks Em dashes (U+2014), En dashes (U+2013), Thin Spaces (U+2009), En Spaces (U+2002), Em Spaces (U+2003) and Ideographic Spaces (U+3000). It would be helpful to have a similar feature in the Extension:CodeMirror."