Supercharge your shift key. Tap it for parentheses. Hold it for shift.
As Steve Losh points out in his Modern Space Cadet post, there are "keys you hold down to change how other keys behave, but that (usually) don’t do anything if you use them on their own" (e.g., shift), and there are "keys that you press and release but don’t want to 'repeat' as you hold them" (e.g., parentheses). "There are two [distinctly] different ways to use [these keys] and they’re each only useful in one of those ways. This means that we can combine them onto a single key without losing any useful functionality!"
With that in mind, we can teach the shift key to pull double duty:
- If shift is pressed and released in isolation, we can generate a pair of parentheses and locate the cursor between them
- If shift is held down and used in combination with another key, then we can let it provide the normal shift key behavior
This functionality is developed and tested with the following dependencies:
- macOS Sierra 10.12
- Hammerspoon 0.9.54
mkdir -p ~/.hammerspoon/Spoons
git clone https://github.com/dccxi/ShiftParentheses.spoon.git ~/.hammerspoon/Spoons/ShiftParentheses.spoon
cd ~/.hammerspoon/Spoons/ShiftParentheses.spoon
script/setupNow you're ready to rock. 🤘
If you prefer to roll your own Hammerspoon config, this code is also available as a Spoon. Just look for ShiftParentheses.spoon.zip included with the latest release.
Shout-out to @arbelt and @jasoncodes for the original implementation of this functionality. ⚡️🍻🌟
This code is an adaptation of their work:
- https://gist.github.com/arbelt/b91e1f38a0880afb316dd5b5732759f1
- https://github.com/jasoncodes/dotfiles/blob/ac9f3ac/hammerspoon/control_escape.lua
Still reading? Dude, you're pretty serious about your keyboard. 
Lucky for you, there's more where this came from. Check out jasonrudolph/keyboard for even more fun. ⌨🤓