feat: --execute flag which runs the passed keymap before launch

[nik-rev]

Adds a new flag -e/--execute which gets passed a command to execute before launching helix.

Why: Currently, when passing a directory to Helix like hx .. it will open a file finder <space>f.

What if instead of that, you want to open it with a file explorer <space>e? This PR allows you to do this by using hx .. --execute "<esc><space>e" which will open the file explorer instead

It allows for more versatility as well: you'll be able to start helix with whatever sequence of commands you want

[satoqz]

Another use case I've thought of previously was setting the language for text that's piped into helix:

some-command | hx -x ':lang bash<ret>'

Edit: Yeah, this works great:

ghostty +show-config --docs --default | hx --execute ':lang ghostty<ret>'

[Axlefublr]

this is incredible! my long standing usecase of “open file automatically in insert mode, at the end of the last line” can finally be solved 🚀

[Axlefublr]

yay it works :D no merge conflict no errors nothing :D
my one recommendation is to change the short flag from -x to -e
a bit bikesheddy, sure, but various programs tend to use -e as their flag for various exec/eval behavior, so it'll be a bit more natural / memorable for most users

[DerSaidin]

Why take a keymap rather than the commands the keys are mapped to?

e.g.

hx .. --execute "<esc><space>e"

• maybe easier to remember
• maybe shorter

vs

hx .. --execute "file_explorer"

• (equivalent command under default binding)
• don't need to do mode changes to access the command you want to use
• robust to any hx keybind config (e.g. custom; or if defaults change)
• more readable if used in scripts

[Axlefublr]

syntax would need to be introduced to chain commands, in that case 🤔 surrounding in [] probably

[nik-rev]

Why take a keymap rather than the commands the keys are mapped to?

e.g.

hx .. --execute "<esc><space>e"

• maybe easier to remember
• maybe shorter

vs

hx .. --execute "file_explorer"

• (equivalent command under default binding)
• don't need to do mode changes to access the command you want to use
• robust to any hx keybind config (e.g. custom; or if defaults change)
• more readable if used in scripts

• if you want to name the commands explicitly you can just use the command picker: <esc><space>?file_explorer<enter>
• people usually don't know names of commands, so its an extra step to look them up
• helix isn't meant to be used from scripts. you'd be better off with a programming language for that. this feature is for enhancing interactive usage
• series of commands is much less capable than an arbitrary key sequence. this would make the feature less useful. e.g. you won't be able to open a picker with some things typed in the prompt
• it would make the feature more complex, which means its much less likely to be merged