ShowParamterHelp is bound to Alt+h by default which doesn't work on macOS

[SteveL-MSFT]

Environment

PS version: 7.2.0-preview.3
PSReadline version: 2.2.0-beta2
os: Darwin mmomalife.northamerica.corp.microsoft.com 20.3.0 Darwin Kernel Version 20.3.0: Thu Jan 21 00:07:06 PST 2021; root:xnu-7195.81.3~1/RELEASE_X86_64 x86_64
PS file version: 7.2.0.0
HostName: ConsoleHost
BufferWidth: 381
BufferHeight: 94

By default 2.2-beta2 binds Alt+h to ShowParameterHelp, but Alt+h on macOS prints Unicode 0xCB99 instead of calling the key handler. There is already an issue with .NET in not catching some keyboard combinations correctly on Unix systems. For now, it may make sense to pick a different default binding that works on Windows and Linux/macOS. Perhaps F2?

[daxian-dbw]

@theJasonHelmick and I had a discussion about this on Monday. We thought about choosing a different key binding, but decided to postpone the change.
It works fine on Linux, but not on macOS because of #1075. There are many existing default bindings today using combination keys with Alt, and all of them are not working on macOS. So we should fix #1075 as it's the root cause. But I'm fine that we choose different default binding for parameter help. F2 is already taken, to switch between prediction views.

[adityapatwardhan]

How about Ctrl+F1. Still related to F1 so keeps the help chords together?

[theJasonHelmick]

The same problem exists with ALT-a as well - any ALT key combinations on MAc. I have remapped them as Ctrl-L and Ctrl-k. I'm not recommending these mappings, but more to @adityapatwardhan point - I think that loading up the function keys with ctrl options might not work well - as a Mac user, one method of accessing the function keys is to press Fn + the function key - this would make it Fn+Ctrl+F1 - which is a stretch.

[mklement0]

It's not ideal, but a one-time configuration of the macOS terminal apps makes the Alt-based shortcuts work:

See #1075 (comment)

[andyleejordan]

Edit: Oops yeah exactly what @mklement0 linked to! Sorry didn't read, it was just the notification that pulled me over lol.

Have you all tried setting "Use option as meta key" in macOS's terminal settings? This works for me, been doing it since 2012 to get all my Alt- combos in terminal Emacs working 😆

[mklement0]

Thanks, @andschwa, let me just duplicate the info from the linked comment for convenience here, so as to also cover iTerm2 users:

Preferences > Profiles > (profile of interest) > Keys > Left Option key: / Right Option key:

Choose ESC+.