config: change macos-option-as-alt default to left

[mitchellh]

As suggested: #2363 (comment)

This allows users of non-US keyboard layouts to continue to use the right option key for input methods, while still being able to use the the left option key as alt for keybindings.

This is a bit of an experiment to see if this is a good default for everyone. This is in response to very common confusion of US keyboard layouts where "alt" doesn't work along with the very common use of non-US layouts where the right option key is used for input methods. I think this will strike the right balance for most users.

[clason]

That's a bit of a nasty change at least on German keyboard layouts since, e.g., { is option-8 -- which means you'd need to use the left hand for option because 8 is in the right-hand half of the keyboard (and even moreso for } == option-9).

While it's easy to work around, I would argue that this not a good default since virtually no application on macOS has this behavior (by default).

(In fact, my first reaction was "oh no, international keyboard entry is broken again...")

[mitchellh]

Thanks for the report. That was what I was concerned about. I thought all international usage with terminals normalized to the right. Perhaps I can detect a US layout (and expand that list over time) to set this config.

[net]

@clason how do German users typically use alt in the terminal on macOS?

[clason]

I've never needed to; ctrl was more than enough for me. Having alt for input encoding is much more important.

[mitchellh]

Indeed. My experience is alt is very rare to use (also evident by very few people asking about this config). I think making this default US only is the way to go.

[mitchellh]

Reverted this change until it can be done in a way that excludes non-US users.

[mitchellh]

#2930