Add autocmd

[pit-ray]

#89, #100

[pit-ray]

I'm considering following commands.

command	syntax
autocmd	[au]tocmd {event} {aupat} {cmd}
autocmd!	[au]tocmd! {event} {aupat} {cmd}

autocmd

It adds {cmd} into autocmd list for {aupat}, autocmd pattern, corresponding to {event}. As such as Vim, this function does not overwrite but append {cmd} into a list even if the same {cmd} has already existed in a list. The event does not allow us to use *. If you want to add a command to some events at the same time, , without after-space is available. The rule of {aupat} is based on the original Vim. Of course, registered {cmd}s will execute in order added.

autocmd!

It remove all autocmd matched {event} and {aupat}, then register {cmd} after delete. The following syntaxes are available.

au[tocmd]! {event} {aupat} {cmd}
au[tocmd]! {event} {aupat}
au[tocmd]! * {aupat}
au[tocmd]! {event}

Each features are the same as the original Vim.

Implementation

I plan to adopt the following data structure.

https://github.com/vim/vim/blob/b26592a84c8f578c8fbe83cf02ebb47453de1683/src/autocmd.c#L16-L50

figure

[pit-ray]

Considering events.

Event	Happen
AppEnter	Select application
AppLeave	Unselect application
GNormalEnter	Enter to GUI normal mode
GNormalLeave	Leave from GUI normal mode
GVisualEnter	Enter to GUI visual mode
GVisualLeave	Leave from GUI visual mode
ENormalEnter	Enter to editor normal mode
ENormalLeave	Leave from editor normal mode
EVisualEnter	Enter to editor visual mode
EVisualLeave	Leave from editor visual mode
InsertEnter	Enter to insert mode
InsertLeave	Leave from insert mode
ResidentEnter	Enter to resident mode
ResidentLeave	Leave from resident mode
CmdLineEnter	Enter to command mode
CmdLineLeave	Leave from command mode