perf(cmdline): reduce spurious cursor and char events

[soifou]

See discussion in #1952 (comment)

For Neovim 0.11, there’s no real change to the core logic, I added throttling for rapid cursor movements. Considering as "rapid", a cursor move below 60ms from the last "move" (char added included). This is not an ideal solution but I don't see a better option for now.

For Neovim 0.10, I simplified the logic. In both cases, the number of triggered events is reduced by at least 50%, should be easier on downstream listeners and, in my opinion, only includes the meaningful events.

Test case

-- abbreviation
vim.keymap.set('ca', 'mes', 'Messages')
vim.api.nvim_create_user_command('Messages', 'echo "It works!"', {})

User action	Cmdline
:=	:=
<SPACE>	:=
<ALT+v> (paste)	:= vim.treesitter.
f	:= vim.treesitter.f
oldexpr (accept)	:= vim.treesitter.foldexpr
<C-w>	:= vim.treesitter.
<C-w>	:= vim.treesitter
<C-w>	:= vim.
<C-u>	:
mes<CR> (abbrev)	:mes -> : -> :Messages

Events triggered

Version	Original	Patched
0.11	22	11
0.10	20	11

Details

0.11 original

{ char = "=", event = "on_char_added" } 
{ char = " ", event = "on_char_added" }
{ char = ".", event = "on_char_added" } 
{ char = "f", event = "on_char_added" }
{ char = ".", event = "on_cursor_moved" } 
{ char = "r", event = "on_cursor_moved" } 
{ char = ".", event = "on_cursor_moved" } 
{ char = "", event = "on_cursor_moved" } 
{ char = "m", event = "on_char_added" } 
{ char = "e", event = "on_char_added" } 
{ char = "s", event = "on_char_added" } 
{ char = "e", event = "on_cursor_moved" } 
{ char = "m", event = "on_cursor_moved" } 
{ char = "", event = "on_cursor_moved" } 
{ char = "M", event = "on_cursor_moved" } 
{ char = "e", event = "on_cursor_moved" }
{ char = "s", event = "on_cursor_moved" } 
{ char = "s", event = "on_cursor_moved" } 
{ char = "a", event = "on_cursor_moved" } 
{ char = "g", event = "on_cursor_moved" } 
{ char = "e", event = "on_cursor_moved" } 
{ char = "s", event = "on_cursor_moved" }

0.11 patched

{ char = "=", event = "on_char_added" } 
{ char = " ", event = "on_char_added" }
{ char = ".", event = "on_char_added" } 
{ char = "f", event = "on_char_added" }
{ char = ".", event = "on_cursor_moved" } 
{ char = "r", event = "on_cursor_moved" } 
{ char = ".", event = "on_cursor_moved" } 
{ char = "", event = "on_cursor_moved" } 
{ char = "m", event = "on_char_added" } 
{ char = "e", event = "on_char_added" } 
{ char = "s", event = "on_char_added" } 

0.10 original

{ char = "", event = "on_cursor_moved" }
{ char = "=", event = "on_char_added" }
{ char = "=", event = "on_cursor_moved" }
{ char = " ", event = "on_char_added" }
{ char = " ", event = "on_cursor_moved" }
{ char = ".", event = "on_char_added" }
{ char = ".", event = "on_cursor_moved" }
{ char = "f", event = "on_char_added" }
{ char = "f", event = "on_cursor_moved" }
{ char = "r", event = "on_cursor_moved" }
{ char = ".", event = "on_cursor_moved" }
{ char = "r", event = "on_cursor_moved" }
{ char = ".", event = "on_cursor_moved" }
{ char = "", event = "on_cursor_moved" }
{ char = "m", event = "on_char_added" }
{ char = "m", event = "on_cursor_moved" }
{ char = "e", event = "on_char_added" }
{ char = "e", event = "on_cursor_moved" }
{ char = "s", event = "on_char_added" }
{ char = "s", event = "on_cursor_moved" }

0.10 patched

{ char = "=", event = "on_char_added" }
{ char = " ", event = "on_char_added" }
{ char = ".", event = "on_char_added" }
{ char = "f", event = "on_char_added" }
{ char = ".", event = "on_cursor_moved" }
{ char = "r", event = "on_cursor_moved" }
{ char = ".", event = "on_cursor_moved" }
{ char = "", event = "on_cursor_moved" }
{ char = "m", event = "on_char_added" }
{ char = "e", event = "on_char_added" }
{ char = "s", event = "on_char_added" }