Fix working with struct's method

Author: antonmedv

eval_test.go

@@ -586,19 +586,19 @@ func TestEval_panic(t *testing.T) {
 }
 
 func TestEval_method(t *testing.T) {
-	env := testEnv{
+	env := &testEnv{
 		Hello: "hello",
 		World: testWorld{
 			name: []string{"w", "o", "r", "l", "d"},
 		},
-		testVersion: testVersion{
+		testVersion: &testVersion{
 			version: 2,
 		},
 	}
 
-	input := `Title(Hello) ~ ' ' ~ (CompareVersion(1, 3) ? World.String() : '')`
+	input := `Title(Hello) ~ Empty() ~ (CompareVersion(1, 3) ? World.String() : '')`
 
-	node, err := expr.Parse(input)
+	node, err := expr.Parse(input, expr.Env(&testEnv{}))
 	fmt.Printf("%#v\n", node)
 	if err != nil {
 		t.Fatal(err)
@@ -619,7 +619,7 @@ type testVersion struct {
 	version float64
 }
 
-func (c testVersion) CompareVersion(min, max float64) bool {
+func (c *testVersion) CompareVersion(min, max float64) bool {
 	return min < c.version && c.version < max
 }
 
@@ -632,11 +632,15 @@ func (w testWorld) String() string {
 }
 
 type testEnv struct {
-	testVersion
+	*testVersion
 	Hello string
 	World testWorld
 }
 
-func (e testEnv) Title(s string) string {
+func (e *testEnv) Title(s string) string {
 	return strings.Title(s)
 }
+
+func (e *testEnv) Empty() string {
+	return " "
+}

parser.go

@@ -140,14 +140,22 @@ func (p *parser) createTypesTable(i interface{}) typesTable {
 	v := reflect.ValueOf(i)
 	t := reflect.TypeOf(i)
 
-	t = dereference(t)
-	if t == nil {
-		return types
+	d := t
+	if t.Kind() == reflect.Ptr {
+		d = t.Elem()
 	}
 
-	switch t.Kind() {
+	switch d.Kind() {
 	case reflect.Struct:
-		types = p.fromStruct(t)
+		types = p.fieldsFromStruct(d)
+
+		// Methods of struct should be gathered from original struct with pointer,
+		// as methods maybe declared on pointer receiver. Also this method retrieves
+		// all embedded structs methods as well, no need to recursion.
+		for i := 0; i < t.NumMethod(); i++ {
+			m := t.Method(i)
+			types[m.Name] = m.Type
+		}
 
 	case reflect.Map:
 		for _, key := range v.MapKeys() {
@@ -161,7 +169,7 @@ func (p *parser) createTypesTable(i interface{}) typesTable {
 	return types
 }
 
-func (p *parser) fromStruct(t reflect.Type) typesTable {
+func (p *parser) fieldsFromStruct(t reflect.Type) typesTable {
 	types := make(typesTable)
 	t = dereference(t)
 	if t == nil {
@@ -174,18 +182,13 @@ func (p *parser) fromStruct(t reflect.Type) typesTable {
 			f := t.Field(i)
 
 			if f.Anonymous {
-				for name, typ := range p.fromStruct(f.Type) {
+				for name, typ := range p.fieldsFromStruct(f.Type) {
 					types[name] = typ
 				}
 			}
 
 			types[f.Name] = f.Type
 		}
-
-		for i := 0; i < t.NumMethod(); i++ {
-			m := t.Method(i)
-			types[m.Name] = m.Type
-		}
 	}
 
 	return types

runtime.go

@@ -103,9 +103,14 @@ func extract(val interface{}, i interface{}) (interface{}, bool) {
 
 func getFunc(val interface{}, i interface{}) (interface{}, bool) {
 	v := reflect.ValueOf(val)
-	switch v.Kind() {
+	d := v
+	if v.Kind() == reflect.Ptr {
+		d = v.Elem()
+	}
+
+	switch d.Kind() {
 	case reflect.Map:
-		value := v.MapIndex(reflect.ValueOf(i))
+		value := d.MapIndex(reflect.ValueOf(i))
 		if value.IsValid() && value.CanInterface() {
 			return value.Interface(), true
 		}
@@ -119,11 +124,6 @@ func getFunc(val interface{}, i interface{}) (interface{}, bool) {
 		if value.IsValid() && value.CanInterface() {
 			return value.Interface(), true
 		}
-	case reflect.Ptr:
-		value := v.Elem()
-		if value.IsValid() && value.CanInterface() {
-			return getFunc(value.Interface(), i)
-		}
 	}
 	return nil, false
 }