supported embedded structs

Author: aksentyev

parser.go

@@ -134,6 +134,10 @@ func With(i interface{}) OptionFn {
 			for i := 0; i < t.NumField(); i++ {
 				f := t.Field(i)
 				p.types[f.Name] = f.Type
+
+				for name, typ := range p.findEmbeddedFieldNames(f.Type) {
+					p.types[name] = typ
+				}
 			}
 		case reflect.Map:
 			for _, key := range v.MapKeys() {
@@ -146,6 +150,26 @@ func With(i interface{}) OptionFn {
 	}
 }
 
+func (p *parser) findEmbeddedFieldNames(t reflect.Type) map[string]Type {
+	res := make(map[string]Type)
+	if t.Kind() == reflect.Struct {
+		for i := 0; i < t.NumField(); i++ {
+			f := t.Field(i)
+			if f.Type.Kind() == reflect.Struct && f.Type.Name() == f.Name {
+				for name, typ := range p.findEmbeddedFieldNames(f.Type) {
+					res[name] = typ
+				}
+
+				return res
+			}
+
+			res[f.Name] = f.Type
+		}
+	}
+
+	return res
+}
+
 func (p *parser) errorf(format string, args ...interface{}) *syntaxError {
 	return &syntaxError{
 		message: fmt.Sprintf(format, args...),

parser_test.go

@@ -207,3 +207,24 @@ func TestParse_error(t *testing.T) {
 		}
 	}
 }
+
+func TestParser_findEmbeddedFieldNames(t *testing.T) {
+	type (
+		C struct {
+			F int
+		}
+
+		B struct {
+			C
+		}
+
+		A struct {
+			B
+		}
+	)
+
+	res := new(parser).findEmbeddedFieldNames(reflect.TypeOf(A{}))
+	if res["F"] != reflect.TypeOf(1) {
+		t.Error("expected embedded struct field")
+	}
+}

type.go

@@ -331,13 +331,36 @@ func fieldType(ntype Type, name string) (Type, bool) {
 		case reflect.Interface:
 			return interfaceType, true
 		case reflect.Struct:
-			if t, ok := ntype.FieldByName(name); ok {
+			t, ok := ntype.FieldByName(name)
+			if ok {
 				return t.Type, true
 			}
+
+			if t, ok := checkEmbeddedFieldNames(ntype, name); ok {
+				return t, true
+			}
 		case reflect.Map:
 			return ntype.Elem(), true
 		}
 	}
+
+	return nil, false
+}
+
+func checkEmbeddedFieldNames(t reflect.Type, name string) (Type, bool) {
+	if t.Kind() == reflect.Struct {
+		for i := 0; i < t.NumField(); i++ {
+			f := t.Field(i)
+			if f.Type.Kind() == reflect.Struct {
+				return checkEmbeddedFieldNames(f.Type, name)
+			}
+
+			if f.Name == name {
+				return f.Type, true
+			}
+		}
+	}
+
 	return nil, false
 }
 

type_test.go

@@ -69,6 +69,7 @@ var typeTests = []typeTest{
 	"Int + Int + Int",
 	"Int % Int > 1",
 	"Int in Int..Int",
+	"FieldStr == 'test'",
 }
 
 var typeErrorTests = []typeErrorTest{
@@ -273,7 +274,13 @@ type foo struct {
 	Fn  func()
 	Abc abc
 }
+
+type StringStruct struct {
+	FieldStr string
+}
+
 type payload struct {
+	StringStruct
 	Abc    abc
 	Foo    *foo
 	Arr    []*foo