diff --git a/README.md b/README.md
index dd6348b..0f90b77 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,8 @@ gogen - Code generator for the Go language
 [![Coverage Status](https://codecov.io/gh/goplus/gogen/branch/main/graph/badge.svg)](https://codecov.io/gh/goplus/gogen)
 [![GoDoc](https://pkg.go.dev/badge/github.com/goplus/gogen.svg)](https://pkg.go.dev/github.com/goplus/gogen)
 
+`gogen` is a general-purpose Go code generation toolkit. Like the Go compiler, It can perform type checking of expressions. For example, if you generate an expression like `"Hello" + 1`, it will report the corresponding error.
+
 ## Quick start
 
 Create a file named `hellogen.go`, like below:
diff --git a/func.go b/func.go
index dfb80a3..1473b10 100644
--- a/func.go
+++ b/func.go
@@ -132,6 +132,7 @@ func (p *Func) End(cb *CodeBuilder, src ast.Node) {
 	}
 }
 
+// NewFuncDecl creates a new function without function body (declaration only).
 func (p *Package) NewFuncDecl(pos token.Pos, name string, sig *types.Signature) *Func {
 	f, err := p.NewFuncWith(pos, name, sig, nil)
 	if err != nil {
@@ -142,7 +143,7 @@ func (p *Package) NewFuncDecl(pos token.Pos, name string, sig *types.Signature)
 	return f
 }
 
-// NewFunc func
+// NewFunc creates a new function (should have a function body).
 func (p *Package) NewFunc(recv *Param, name string, params, results *Tuple, variadic bool) *Func {
 	sig := types.NewSignatureType(recv, nil, nil, params, results, variadic)
 	f, err := p.NewFuncWith(token.NoPos, name, sig, nil)
@@ -159,7 +160,7 @@ func getRecv(recvTypePos func() token.Pos) token.Pos {
 	return token.NoPos
 }
 
-// NewFuncWith func
+// NewFuncWith creates a new function (should have a function body).
 func (p *Package) NewFuncWith(
 	pos token.Pos, name string, sig *types.Signature, recvTypePos func() token.Pos) (*Func, error) {
 	if name == "" {
diff --git a/import.go b/import.go
index f89e301..5959144 100644
--- a/import.go
+++ b/import.go
@@ -97,6 +97,11 @@ func isGopCommon(name string) bool {
 
 // InitThisGopPkg initializes a Go+ package.
 func InitThisGopPkg(pkg *types.Package) {
+	InitThisGopPkgEx(pkg, nil)
+}
+
+// InitThisGopPkg initializes a Go+ package. pos map overload name to postion.
+func InitThisGopPkgEx(pkg *types.Package, pos map[string]token.Pos) {
 	scope := pkg.Scope()
 	gopos := make([]string, 0, 4)
 	overloads := make(map[omthd][]types.Object)
@@ -156,7 +161,7 @@ func InitThisGopPkg(pkg *types.Package) {
 				}
 			}
 			if len(fns) > 0 {
-				newOverload(pkg, scope, m, fns)
+				newOverload(pkg, scope, m, fns, pos)
 			}
 			delete(overloads, m)
 		}
@@ -164,7 +169,7 @@ func InitThisGopPkg(pkg *types.Package) {
 	for key, items := range overloads {
 		off := len(key.name) + 2
 		fns := overloadFuncs(off, items)
-		newOverload(pkg, scope, key, fns)
+		newOverload(pkg, scope, key, fns, pos)
 	}
 	for name, items := range onameds {
 		off := len(name) + 2
@@ -310,19 +315,19 @@ func checkOverloads(scope *types.Scope, gopoName string) (ret []string, exists b
 	return
 }
 
-func newOverload(pkg *types.Package, scope *types.Scope, m omthd, fns []types.Object) {
+func newOverload(pkg *types.Package, scope *types.Scope, m omthd, fns []types.Object, pos map[string]token.Pos) {
 	if m.typ == nil {
 		if debugImport {
 			log.Println("==> NewOverloadFunc", m.name)
 		}
-		o := NewOverloadFunc(token.NoPos, pkg, m.name, fns...)
+		o := NewOverloadFunc(pos[m.name], pkg, m.name, fns...)
 		scope.Insert(o)
 		checkGoptsx(pkg, scope, m.name, o)
 	} else {
 		if debugImport {
 			log.Println("==> NewOverloadMethod", m.typ.Obj().Name(), m.name)
 		}
-		NewOverloadMethod(m.typ, token.NoPos, pkg, m.name, fns...)
+		NewOverloadMethod(m.typ, pos[m.typ.Obj().Name()+"."+m.name], pkg, m.name, fns...)
 	}
 }