fix: on Windows, use zig compiler for treesitter instead of clang

On Windows:

Rust: `cargo build` -> builds successfully.
Zig: `zig build-exe` -> builds successfully.
C++: `clang++ main.cpp` -> unable to find a visual studio installation; try running clang from a developer command prompt [-wmsvc-not-found]

Windows C++ toolchain is still a joke today, and the joke's not funny
anymore.

As the zig way of building treesitter is unstable on other platforms,
limit zig usage to just Windows.

docs/setup.md

@@ -5,9 +5,10 @@
 ### Common
 * Rust
     * Rationale: Mainly for compiling
-* Clang
-    * Plugin users: Treesitter
-    * Note: For Windows, setting up `PATH` is essential so that Treesitter can access clang. For more details, see [Treesitter Wiki](https://github.com/nvim-treesitter/nvim-treesitter/wiki/Windows-support) ("Through Visual Studio")
+* Clang (non-Windows only)
+    * Plugin users: Treesiiter
+* Zig (Windows only)
+    * Plugin users: Treesitter (clang is a pain to setup on Windows)
 * Nodejs
     * Plugin users: Lsp
 * Nerd Fonts

lua/wangleng/plugins/treesitter.lua

@@ -4,6 +4,13 @@ return {
         "nvim-treesitter/nvim-treesitter",
         build = ":TSUpdate",
         config = function()
+            local is_win32 = vim.fn.has('win32') == 1
+
+            if is_win32 then
+                -- on Windows, it is a pain to set up clang properly
+                require("nvim-treesitter.install").compilers = { "zig" }
+            end
+
             local configs = require("nvim-treesitter.configs")
 
             configs.setup({
@@ -19,7 +26,9 @@ return {
                     "zig",
                 },
                 -- install parsers synchronously (only applied to `ensure_installed`)
-                sync_install = false,
+                -- zig can only install synchronously, async install somehow have problems
+                -- (and since Windows is using zig, have to disable async install, which is the default)
+                sync_install = is_win32,
                 -- enable highlighting
                 highlight = { enable = true },
                 -- enable indent behaviour when using '=' operator
@@ -28,4 +37,3 @@ return {
         end
     },
 }
-