feat: add impl support

docs: add impl

lua/gopher/impl.lua

@@ -0,0 +1,74 @@
+local Job = require "plenary.job"
+local ts_utils = require "gopher._utils.ts"
+
+local function get_struct()
+  local ns = ts_utils.get_struct_node_at_pos(unpack(vim.api.nvim_win_get_cursor(0)))
+  if ns == nil then
+    print "put cursor on struct or specify a receiver"
+    return ""
+  end
+
+  vim.api.nvim_win_set_cursor(0, {
+    ns.dim.e.r,
+    ns.dim.e.c,
+  })
+
+  return ns.name
+end
+
+return function(...)
+  local args = { ... }
+  local iface, recv_name = "", ""
+  local recv = get_struct()
+
+  if #args == 0 then
+    iface = vim.fn.input "impl: generating method stubs for interface: "
+    vim.cmd "redeaw!"
+    if iface == "" then
+      print "usage: GoImpl f *File io.Reader"
+    end
+  elseif #args == 1 then -- :GoImpl io.Reader
+    recv = string.lower(recv) .. " *" .. recv
+    vim.cmd "redraw!"
+    iface = select(1, ...)
+  elseif #args == 2 then -- :GoImpl w io.Writer
+    recv_name = select(1, ...)
+    recv = string.format("%s *%s", recv_name, recv)
+    iface = select(#args, ...)
+  elseif #args > 2 then
+    iface = select(#args, ...)
+    recv = select(#args - 1, ...)
+    recv_name = select(#args - 2, ...)
+    recv = string.format("%s %s", recv_name, recv)
+  end
+
+  -- stylua: ignore
+  local cmd_args = {
+    "-dir", vim.fn.fnameescape(vim.fn.expand "%:p:h"), ---@diagnostic disable-line: missing-parameter
+    recv,
+    iface
+  }
+
+  local res_data
+  Job
+    :new({
+      command = "impl",
+      args = cmd_args,
+      on_exit = function(data, retval)
+        if retval ~= 0 then
+          print("command exited with code " .. retval)
+          return
+        end
+
+        res_data = data:result()
+      end,
+    })
+    :sync()
+
+  local pos = vim.fn.getcurpos()[2]
+  table.insert(res_data, 1, "")
+  vim.fn.append(pos, res_data)
+
+  -- table.insert(res_data, 1, "")
+  -- vim.fn.append(vim.fn.getcurpos()[2], res_data)
+end