neovim

commit 3869a2e0cf25323a8e5235840678b147ca908517
parent d40d34aaa5720b67da629b4ca74674dfd4b9221c
Author: jdrouhard <john@drouhard.dev>
Date:   Mon, 12 Dec 2022 11:42:37 -0600

perf(lsp): update semantic tokens algorithm for parsing modifiers (#21383)

Instead of testing for every possible modifier type, only test bits up
to the highest set in the token array. Saves many bit ops and
comparisons when there are no modifiers or when the highest set bit is a
lower bit than the highest possible in the legend on average.

Can be further simplified when non-luaJIT gets the full bit module (see #21222)
Diffstat:
M
runtime/lua/vim/lsp/semantic_tokens.lua
 | 
26
+++++++++++++-------------
M
test/functional/plugin/lsp/semantic_tokens_spec.lua
 | 
23
-----------------------

2 files changed, 13 insertions(+), 36 deletions(-)
diff --git a/runtime/lua/vim/lsp/semantic_tokens.lua b/runtime/lua/vim/lsp/semantic_tokens.lua
@@ -55,22 +55,22 @@ end
 ---@private
 ---@return string[]
 local function modifiers_from_number(x, modifiers_table)
-  ---@private
-  local function _get_bit(n, k)
-    --TODO(jdrouhard): remove once `bit` module is available for non-LuaJIT
+  local modifiers = {}
+  local idx = 1
+  while x > 0 do
     if _G.bit then
-      return _G.bit.band(_G.bit.rshift(n, k), 1)
+      if _G.bit.band(x, 1) == 1 then
+        modifiers[#modifiers + 1] = modifiers_table[idx]
+      end
+      x = _G.bit.rshift(x, 1)
     else
-      return math.floor((n / math.pow(2, k)) % 2)
-    end
-  end
-
-  local modifiers = {}
-  for i = 0, #modifiers_table - 1 do
-    local b = _get_bit(x, i)
-    if b == 1 then
-      modifiers[#modifiers + 1] = modifiers_table[i + 1]
+      --TODO(jdrouhard): remove this branch once `bit` module is available for non-LuaJIT (#21222)
+      if x % 2 == 1 then
+        modifiers[#modifiers + 1] = modifiers_table[idx]
+      end
+      x = math.floor(x / 2)
     end
+    idx = idx + 1
   end
 
   return modifiers
diff --git a/test/functional/plugin/lsp/semantic_tokens_spec.lua b/test/functional/plugin/lsp/semantic_tokens_spec.lua
@@ -459,29 +459,6 @@ describe('semantic token highlighting', function()
         {1:~                                       }|
                                                 |
       ]] }
-
-      exec_lua([[
-        vim.lsp.semantic_tokens.start(bufnr, client_id)
-      ]])
-
-      screen:expect { grid = [[
-        #include <iostream>                     |
-                                                |
-        int main()                              |
-        {                                       |
-            int x;                              |
-        #ifdef __cplusplus                      |
-            std::cout << x << "\n";             |
-        #else                                   |
-            printf("%d\n", x);                  |
-        #endif                                  |
-        }                                       |
-        ^}                                       |
-        {1:~                                       }|
-        {1:~                                       }|
-        {1:~                                       }|
-                                                |
-        ]], unchanged = true }
     end)
 
     it('does not send delta requests if not supported by server', function()