Still wasting time looking at possible micro-optimizations on the CLI side. The MacBook M4 Pro is a beast, and I found it reduced by a fair amount (~ 40%) Neovim startup time. Digging into how fast it starts now (using vim-startuptime and hyperfine), I found the following:
scratch master* 2m44s
» hyperfine "nvim --headless +qa" --warmup 5
Benchmark 1: nvim --headless +qa
Time (mean ± σ): 32.5 ms ± 0.4 ms [User: 19.0 ms, System: 7.1 ms]
Range (min … max): 31.4 ms … 33.7 ms 85 runs
scratch master*
» vim-startuptime --vimpath nvim
Extra options: []
Measured: 10 times
Total Average: 22.782900 msec
Total Max: 28.338000 msec
Total Min: 21.359000 msec
AVERAGE MAX MIN
------------------------------
14.312000 18.240000 13.348000: /Users/chl/.config/nvim/init.lua
5.226100 6.687000 4.827000: require('fzf-lua')
2.576100 3.206000 2.425000: require('nvim-treesitter.configs')
2.393600 2.972000 2.255000: require('nvim-treesitter.query')
2.110400 2.705000 1.979000: require('vim.lsp')
1.709600 2.168000 1.511000: require('fzf-lua.config')
1.443200 1.824000 1.330000: require('fzf-lua.path')
1.227300 1.388000 1.181000: loading rtp plugins
1.133800 1.385000 1.052000: require('nvim-treesitter.tsrange')
1.064300 1.333000 1.004000: require('nvim-treesitter.compat')
1.053900 1.290000 0.977000: require('nvim-treesitter.ts_utils')
1.016600 1.270000 0.961000: require('vim.treesitter')
0.990800 1.184000 0.943000: /Users/chl/.config/nvim/plugin/lisp.lua
0.973200 1.165000 0.927000: nvim_exec2() called at /Users/chl/.config/nvim/plugin/lisp.lua:0
The lisp.lua custom plugin is just here to load slimv which sits as an optional plugin, and so I realized that there was no gain in this case. Better to leave it as a start plugin and remove the custom plugin itself. It makes no difference whatsoever. It’s still much higher than three years ago when I was using a proper package manager and much less Lua code in my init.lua. However, I found that using vim.loader.enable() introduced in Neovim 0.9 resulted in a slight improvement:
~/.config/nvim
» hyperfine "nvim --headless +qa" --warmup 5
Benchmark 1: nvim --headless +qa
Time (mean ± σ): 25.7 ms ± 0.5 ms [User: 12.8 ms, System: 6.7 ms]
Range (min … max): 24.3 ms … 26.9 ms 112 runs
Loading my init.lua is now two times faster as reported by vim-startuptime. #vim