Differences between previewer bat and bat_native?

[josh-nz]

I'm wondering what the differences are between these two previewer settings. The wiki page reads:

the difference between the two is that the former [bat] will use neovim as a proxy to the bat command and bat_native will defer the execution of bat to fzf (hence "native").

I would assume that bat_native is the fastest, but if this is correct, why then do the fzf-native and max-perf profiles use bat and not bat_native (but do use {man|help}_native)?

Aside from speed, are there any other things to consider when deciding between these two settings?

[ibhagwan]

The “native” as its name suggests sets fzf’s preview command directly to bat <args> <filename>, however for filename is then replaced with a neovim --headless --cmd <lua> command in order to properly extract the filename from the entry (strip icons, etc) - this approach has obvious limitations with tags for example where the entry doesn’t have a line number and other issues with Windows where the files index for the line number differs between relative paths and absolute paths (due to the extra C: prefix when our delimiter is :).

The non native version uses a neovim --headless … directly as fzf’s --preview argument and then spawns bat using libuv’s spawn and streams the data over named pipe to fzf.

Both technically are a separate process with the non-native doing a bit more work on neovim’s main thread as opposed to the native version but the perf difference is probably not that big.

why then do the fzf-native and max-perf profiles use bat and not bat_native (but do use {man|help}_native

bat is technically already counted as a “native” previewer, meaning the preview is spawned in the terminal inside fzf’s preview “window”, the reason it’s the default is due to the limitations I explained above (namely tags / Windows) and the fact I’d like to remove it one day :)

[ibhagwan]

Btw, if you want to see this in action, use :FzfLua files previewer=bat debug=true and :FzfLua files previewer=bat_native debug=true and then explore the generated fzf cli in :messages and inspect the --preview arg

bat_native

--preview 'bat --color=always --style=numbers,changes  "$(VIMRUNTIME='\''/usr/share/nvim/ru
ntime'\'' '\''/usr/bin/nvim'\'' -n --headless --clean --cmd '\''lua vim.g.did_load_filetypes=1; loadfile([[/home/bhagwan/Sources/nvim/fzf-lua/lua/fzf-lua/shell_helper.lu
a]])().rpc_nvim_exec_lua({fzf_lua_server=[[/run/user/1000/fzf-lua.1712038571.10020.1]], fnc_id=5 , debug=true})'\'' -- {})"'

bat

--preview 'VIMRUNTIME='\''/usr/share/nvim/runtime'\'' '\''/usr/bin/nvim'\'' -n --headless -
-clean --cmd '\''lua vim.g.did_load_filetypes=1; loadfile([[/home/bhagwan/Sources/nvim/fzf-lua/lua/fzf-lua/shell_helper.lua]])().rpc_nvim_exec_lua({fzf_lua_server=[[/run
/user/1000/fzf-lua.1712038571.10020.1]], fnc_id=6 , debug=true})'\'' -- {})"'