Refactor type checker of fieldType helper

Author: antonmedv

type.go

@@ -374,13 +374,22 @@ func fieldType(ntype Type, name string) (Type, bool) {
 		case reflect.Interface:
 			return interfaceType, true
 		case reflect.Struct:
-			t, ok := ntype.FieldByName(name)
-			if ok {
-				return t.Type, true
+			// First check all struct's fields.
+			for i := 0; i < ntype.NumField(); i++ {
+				f := ntype.Field(i)
+				if !f.Anonymous && f.Name == name {
+					return f.Type, true
+				}
 			}
 
-			if t, ok := checkEmbeddedFieldNames(ntype, name); ok {
-				return t, true
+			// Second check fields of embedded structs.
+			for i := 0; i < ntype.NumField(); i++ {
+				f := ntype.Field(i)
+				if f.Anonymous {
+					if t, ok := fieldType(f.Type, name); ok {
+						return t, true
+					}
+				}
 			}
 		case reflect.Map:
 			return ntype.Elem(), true
@@ -390,26 +399,6 @@ func fieldType(ntype Type, name string) (Type, bool) {
 	return nil, false
 }
 
-func checkEmbeddedFieldNames(t reflect.Type, name string) (Type, bool) {
-	t = dereference(t)
-	if t.Kind() == reflect.Struct {
-		for i := 0; i < t.NumField(); i++ {
-			f := t.Field(i)
-
-			fType := dereference(f.Type)
-			if fType.Kind() == reflect.Struct {
-				return checkEmbeddedFieldNames(fType, name)
-			}
-
-			if f.Anonymous && f.Name == name {
-				return fType, true
-			}
-		}
-	}
-
-	return nil, false
-}
-
 func indexType(ntype Type) (Type, bool) {
 	ntype = dereference(ntype)
 	if ntype == nil {

type_test.go

@@ -73,8 +73,9 @@ var typeTests = []typeTest{
 	"Int + Int + Int",
 	"Int % Int > 1",
 	"Int in Int..Int",
-	"FieldStr == ''",
-	"FieldStr2 == ''",
+	"EmbStr == ''",
+	"EmbPtrStr == ''",
+	"SubStr ~ ''",
 	"OkFn() and OkFn()",
 	"Foo.Fn() or Foo.Fn()",
 }
@@ -280,6 +281,10 @@ var typeErrorTests = []typeErrorTest{
 		"1 in Foo",
 		"invalid operation: 1 in Foo (mismatched types float64 and *expr_test.foo)",
 	},
+	{
+		"Embedded.EmbStr ~ Str",
+		"unknown name Embedded",
+	},
 }
 
 type abc interface {
@@ -293,18 +298,19 @@ type foo struct {
 	Fn  func() bool
 	Abc abc
 }
-
-type StringStruct struct {
-	FieldStr string
+type SubEmbedded struct {
+	SubStr string
 }
-
-type StringStructPtr struct {
-	FieldStr2 string
+type Embedded struct {
+	SubEmbedded
+	EmbStr string
+}
+type EmbeddedPtr struct {
+	EmbPtrStr string
 }
-
 type payload struct {
-	StringStruct
-	*StringStructPtr
+	Embedded
+	*EmbeddedPtr
 	Abc    abc
 	Foo    *foo
 	Arr    []*foo