Em dash is too short

[moubry]

Source Code Pro's em dash feels too short—like it’s more of an en dash.

This character is rarely (never?) used for programming. However, I use it in documentation blocks above code.

[pauldhunt]

@moubry please post some examples.

[frankrolf]

The width of the emdash is somewhat limited by the standard character width of 600 units.
Right now, the hyphen is 430 units wide, the endash is 440 units, the emdash 560.
Maybe there is a point about making the emdash flush to the left and right margin, Paul?

[krono]

Please don't :)
A minimal visible white between the preceding/following character and the emdash is (just in my opinion) increasing legibility and reducing the need of manual kerning.

For example, look at the emdash of the original Palatino and the one of the Linotype Palatino.

[frankrolf]

Hmm – are we really comparing the same kind of issue here?
Source Code Pro is a monospaced font for coding, that means that even the emdash needs to have the same width as all the other characters. I hope nobody will go in and manually kern a monospaced text.
Palatino is a proportional font, and on top of that used in a totally different area.
In writing code, I can imagine few uses for the emdash, apart from making a horizontal line in your documentation string (but then again, we also have Box Drawing Characters which might be more appropriate for that).

[krono]

I understand your concern, you are probably right, most people won't use an emdash for coding.
I just don't think that the em dash should touch other characters, but there's clearly more expertise on your side.

However, it is still difficult to discern the “three dashes” (-, –, —) easily, but this is not limited to source code pro:

[pauldhunt]

this problem is a bit tricky for several reasons: firstly because this is a monospaced font i only have 60% of the full em to work with (each glyph is 600 em units wide). This already forces the em dash to be much narrower than it would be in a proportional font. Secondly for coding the hyphen for coding has been made to match the design of the minus symbol and the mathematical characters have been designed to harmonize with the size and weight of the other numerical glyphs.

I will go ahead and make the em dashes the full width of 600 em to make it more distinct from from the en dash, but there will still be some confusion between endash and hyphen, unless you use the stylistic set with typographic alternates that substitutes a much shorter hyphen for the default form.

If you have further suggestions, I would love to hear your proposed solutions.

[moubry]

Sounds great.

[quicknir]

@pauldhunt Hi, realize I'm coming to this quite a bit after the fact. Could you make the dash shorter then? I know this will sound absurd, but: I just wasted something like a full day trouble-shooting a Nagios server. The culprit turned out to be that I had copied and pasted text from somewhere, and that text had a typo in it, such that I ended up with an en dash instead of a regular dash for a command line command. I've had to switch away from this font in the console for the time being.

[pauldhunt]

@quicknir i need unicode values for what you are calling 'en dash' and 'regular dash'.

[kenlunde]

My guess is U+2013 (EN DASH) and U+002D (HYPHEN-MINUS).

[quicknir]

En dash in UTF 8 is 0xE2 0x80 0x93, or U+2013 if you prefer. Here it is: –. As for dash, I simply mean the ascii character on your keyboard: -. It seems to have the technical name: hyphen-minus, and have code 0x2D, or U+002D. As you can see, these are plainly distinguishable in the font that github uses. In Source Code Pro they are nearly (or perhaps totally) indistinguishable.

[quicknir]

@kenlunde Well played!