Several months ago, I switched to using Iosevka¹ as my main font for both editor and terminal.

It's an awesome font with reasonable defaults while providing the same customizability as Input².

Additionally, it also supports font ligatures³ (while Input removed its support for ligatures in its latest version⁴)

I first noticed this feature in a talk given by Dave Thomas⁵. In this talk, his Elixir code looked better in Emacs with the font ligature feature enabled. (Though, he's using a different font, FiraCode maybe)

So I tried to get the same effect in my Emacs.

Then I found this simple function to enable this feature for emacs-mac-port⁶:

(mac-auto-operator-composition-mode t)

Unfortunately, this function does not exist in GNU Emacs for macOS. Because GNU Emacs doesn't support font ligature yet. (You can kind of enable it via prettify-symbol-mode⁷)

(P.S. actually, I've tried to move back to GNU Emacs for a lightly better performance. But I found I kinda missed this font ligature feature and other nicer integration with the whole macOS system. And the performance of emacs-mac-port got better and better through Emacs 25 and Emacs 26.0.90. So I think I'm gonna stick with emacs-mac-port for a while.)

The result looks like this:

Hope this post can help you! And you can find more information below:

• What would it take to get ligatures working in emacs? · Issue #42 · tonsky/FiraCode
• Programming Ligatures (like in Fira Code—or PragmataPro) · Issue #56 · be5invis/Iosevka