Replace `vim.foo` with `(rawget vim :foo)` via macro about nvim-laurel HOT 2 CLOSED

The scripts for benchmark is meaningless because they're on Lua 5.4.3; Neovim is built with luaJIT.
rawget is slower than regular table access; therefore, this suggestion should be rejected.

Benchmark

• hyperfine --warmup 10 --max-runs 50 'lua -e "local foo; for _=1, 2e7 do foo = _G.string end; print(foo.len(\"bar\"))"' results in

  Benchmark 1: lua -e "local foo; for _=1, 2e7 do foo = _G.string end; print(foo.len(\"bar\"))"
    Time (mean ± σ):     238.8 ms ±  20.0 ms    [User: 235.2 ms, System: 2.4 ms]
    Range (min … max):   216.7 ms … 268.8 ms    11 runs

• hyperfine --warmup 10 --max-runs 50 'lua -e "local foo; for _=1, 2e7 do foo = rawget(_G, \"string\") end; print(foo.len(\"bar\"))"' results in

  Benchmark 1: lua -e "local foo; for _=1, 2e7 do foo = rawget(_G, \"string\") end; print(foo.len(\"bar\"))"
    Time (mean ± σ):     880.1 ms ±  22.6 ms    [User: 878.1 ms, System: 0.9 ms]
    Range (min … max):   854.6 ms … 928.3 ms    10 runs

References

• https://gintenlabo.hatenablog.com/entry/20100715/1279204620 concluded on 2010 Jul 15 that regular table access is faster than rawget/rawset;
• https://www.luaforum.com/index.php?threads/is-there-a-way-to-reffer-a-table-itself-inside-the-same-table.469/ referred to the performance difference, but no one was sure there.

from nvim-laurel.

On LuaJIT in nvim, rawget makes no performance difference compared with regular table access.

Benchmarks

Global access

• Regular table access:

  In /tmp/global-regular.lua,

  for _=1,8e4 do
    print(string.len("foo"))
  end

  hyperfine --warmup 10 --max-runs 100 'nvim --headless --noplugin -u /tmp/global-regular.lua +q'

  Benchmark 1: nvim --headless --noplugin -u /tmp/global-regular.lua +q
    Time (mean ± σ):     262.7 ms ±   8.1 ms    [User: 235.8 ms, System: 21.5 ms]
    Range (min … max):   249.2 ms … 276.5 ms    11 runs

• With rawget:

  In /tmp/global-rawget.lua,

  for _=1,8e4 do
    print(rawget(string, "len")("foo"))
  end

  hyperfine --warmup 10 --max-runs 100 'nvim --headless --noplugin -u /tmp/global-rawget.lua +q'

  Benchmark 1: nvim --headless --noplugin -u /tmp/global-rawget.lua +q
    Time (mean ± σ):     273.0 ms ±   9.7 ms    [User: 248.3 ms, System: 21.7 ms]
    Range (min … max):   249.8 ms … 285.7 ms    11 runs

Local access

• Regular table access:

  In /tmp/local-regular.lua,

  local foo = {
    bar = {baz="qux"}
  }
  for _=1,8e4 do
    print(foo.bar.baz)
  end

  hyperfine --warmup 10 --max-runs 100 'nvim --headless --noplugin -u /tmp/local-regular.lua +q'

  Benchmark 1: nvim --headless --noplugin -u /tmp/local-regular.lua +q
    Time (mean ± σ):     297.1 ms ±   9.0 ms    [User: 257.8 ms, System: 35.1 ms]
    Range (min … max):   282.2 ms … 310.4 ms    10 runs

• With rawget:

  In /tmp/local-rawget.lua,

  local foo = {
    bar = {baz="qux"}
  }
  for _=1,8e4 do
    print(rawget(rawget(foo, "bar"), "baz"))
  end

  hyperfine --warmup 10 --max-runs 100 'nvim --headless --noplugin -u /tmp/local-rawget.lua +q'

  Benchmark 1: nvim --headless --noplugin -u /tmp/local-rawget.lua +q
    Time (mean ± σ):     299.1 ms ±  14.8 ms    [User: 257.7 ms, System: 39.4 ms]
    Range (min … max):   283.1 ms … 327.5 ms    10 runs

vim.api

• Regular table access:

  In /tmp/vim-regular.lua,

  for _=1,8e4 do
    vim.api.nvim_set_keymap("n", "s", "x")
    vim.api.nvim_set_keymap("x", "s", "x")
  end

  hyperfine --warmup 10 --max-runs 100 'nvim --headless --noplugin -u /tmp/vim-regular.lua +q'

  Benchmark 1: nvim --headless --noplugin -u /tmp/vim-regular.lua +q
    Time (mean ± σ):      1.034 s ±  0.004 s    [User: 0.021 s, System: 0.006 s]
    Range (min … max):    1.028 s …  1.038 s    10 runs

• With rawget:

  In /tmp/vim-rawget.lua,

  for _=1,8e4 do
    rawget(rawget(vim, "api"), "nvim_set_keymap")("n", "s", "x")
    rawget(rawget(vim, "api"), "nvim_set_keymap")("x", "s", "x")
  end

  hyperfine --warmup 10 --max-runs 100 'nvim --headless --noplugin -u /tmp/vim-rawget.lua +q'

  Benchmark 1: nvim --headless --noplugin -u /tmp/vim-rawget.lua +q
    Time (mean ± σ):      1.032 s ±  0.005 s    [User: 0.019 s, System: 0.006 s]
    Range (min … max):    1.025 s …  1.037 s    10 runs

from nvim-laurel.