Google took me here, luckily.

So, for you professional editors/writers, will it be useful if we support these kinds of dashes/hyphens separately when we develop our software?

* en dash - using the glyph in the font
* em dash - using the glyph in the font
* 'n'-width dash - stretching the length of hyphen to the width of 'n' of the font, as some fonts do not have en dash glyph in the font
* 'm'-width dash - stretching the length of hyphen to the width of 'm' of the font
* hyphen - just the standard '-' char, right next to '0' (if US Qwerty keyboard layout)
* figure dash - the width of a number or the proceeding number if not fixed width font
* negative sign - use the hyphen (which is shorter than the regular mathematical minus symbol) on the same height with other operators
* minus symbol - same width, center line aligned to the center of plus, multiplication, division operator signs, left-right spacing based on TeX rule

If yes, how would you rate the usefulness/priority?
This is mainly for our equation editor software but it looks most of the concepts/rules should be borrowed from the publishing side.

Thank you for all the info here.