1 files changed, 37 insertions, 0 deletions
diff --git a/.config/nvim/lua/extra.lua b/.config/nvim/lua/extra.lua
new file mode 100644
index 0000000..00d2b7c
--- /dev/null
+++ b/.config/nvim/lua/extra.lua
@@ -0,0 +1,37 @@
+-- show unused zig variables as "DiagnosticUnnecessary" instead of error
+local orig_underline_show = vim.diagnostic.handlers.underline.show
+local custom_ns = vim.api.nvim_create_namespace('custom_unused_ns')
+
+vim.diagnostic.handlers.underline.show = function(namespace, bufnr, diagnostics, opts)
+    local normal_diags = {}
+    local custom_diags = {}
+    for _, diag in ipairs(diagnostics) do
+        if diag.message:find('unused', 1, true) then
+            table.insert(custom_diags, diag)
+        else
+            table.insert(normal_diags, diag)
+        end
+    end
+    if #normal_diags > 0 and orig_underline_show ~= nil then
+        orig_underline_show(namespace, bufnr, normal_diags, opts)
+    end
+    for _, diag in ipairs(custom_diags) do
+        vim.highlight.range(
+            bufnr,
+            custom_ns,
+            'DiagnosticUnnecessary',
+            { diag.lnum, diag.col },
+            { diag.end_lnum, diag.end_col },
+            { inclusive = false }
+        )
+    end
+end
+
+local orig_underline_hide = vim.diagnostic.handlers.underline.hide
+
+vim.diagnostic.handlers.underline.hide = function(namespace, bufnr)
+    if orig_underline_hide ~= nil then
+        orig_underline_hide(namespace, bufnr)
+    end
+    vim.api.nvim_buf_clear_namespace(bufnr, custom_ns, 0, -1)
+end