nvim: Add telescope to switch rust-analyzer target

tree/.config/nvim/lua/fns.lua

@@ -0,0 +1,26 @@
+-- change rust-analyzer target
+set_rust_target = function(target)
+    print("rust-analyzer.cargo.target = " .. target)
+    require("rust-tools").setup({
+      server = { settings = { ["rust-analyzer"] = { cargo = { target = target } } } },
+    })
+end
+
+-- a custom telescope picker for changing rust-analyzer target
+pick_rust_target = function(opts)
+  opts = opts or {}
+  require("telescope.pickers").new(opts, {
+    prompt_title = "rustup target list --installed",
+    finder = require("telescope.finders").new_oneshot_job({ "rustup", "target", "list", "--installed" }, opts ),
+    sorter = require("telescope.config").values.generic_sorter(opts),
+    attach_mappings = function(prompt_bufnr, map)
+      local actions = require("telescope.actions")
+      actions.select_default:replace(function()
+        actions.close(prompt_bufnr)
+        local selection = require("telescope.actions.state").get_selected_entry()
+        set_rust_target(selection[1])
+      end)
+      return true
+    end,
+  }):find()
+end