Add support of mixed-type array (#376)

Fixes #357

marshal.go

@@ -475,7 +475,7 @@ func (e *Encoder) valueToTree(mtype reflect.Type, mval reflect.Value) (*Tree, er
 				return nil, err
 			}
 			if e.quoteMapKeys {
-				keyStr, err := tomlValueStringRepresentation(key.String(), "", "", e.arraysOneElementPerLine)
+				keyStr, err := tomlValueStringRepresentation(key.String(), "", "", OrderPreserve, e.arraysOneElementPerLine)
 				if err != nil {
 					return nil, err
 				}
@@ -503,9 +503,6 @@ func (e *Encoder) valueToTreeSlice(mtype reflect.Type, mval reflect.Value) ([]*T
 
 // Convert given marshal slice to slice of toml values
 func (e *Encoder) valueToOtherSlice(mtype reflect.Type, mval reflect.Value) (interface{}, error) {
-	if mtype.Elem().Kind() == reflect.Interface {
-		return nil, fmt.Errorf("marshal can't handle []interface{}")
-	}
 	tval := make([]interface{}, mval.Len(), mval.Len())
 	for i := 0; i < mval.Len(); i++ {
 		val, err := e.valueToToml(mtype.Elem(), mval.Index(i))

marshal_test.go

@@ -2995,10 +2995,6 @@ func TestMarshalInterface(t *testing.T) {
 		InterfacePointerField *interface{}
 	}
 
-	type ShouldNotSupportStruct struct {
-		InterfaceArray []interface{}
-	}
-
 	expected := []byte(`ArrayField = [1,2,3]
 InterfacePointerField = "hello world"
 PrimitiveField = "string"
@@ -3049,11 +3045,6 @@ PrimitiveField = "string"
 	} else {
 		t.Fatal(err)
 	}
-
-	// according to the toml standard, data types of array may not be mixed
-	if _, err := Marshal(ShouldNotSupportStruct{[]interface{}{1, "a", true}}); err == nil {
-		t.Errorf("Should not support []interface{} marshaling")
-	}
 }
 
 func TestUnmarshalToNilInterface(t *testing.T) {
@@ -3367,6 +3358,77 @@ func TestUnmarshalSliceFail2(t *testing.T) {
 
 }
 
+func TestMarshalMixedTypeArray(t *testing.T) {
+	type InnerStruct struct {
+		IntField int
+		StrField string
+	}
+
+	type TestStruct struct {
+		ArrayField []interface{}
+	}
+
+	expected := []byte(`ArrayField = [3.14,100,true,"hello world",{IntField = 100,StrField = "inner1"},[{IntField = 200,StrField = "inner2"},{IntField = 300,StrField = "inner3"}]]
+`)
+
+	if result, err := Marshal(TestStruct{
+		ArrayField:[]interface{}{
+			3.14,
+			100,
+			true,
+			"hello world",
+			InnerStruct{
+				IntField:100,
+				StrField:"inner1",
+			},
+			[]InnerStruct{
+				{IntField:200,StrField:"inner2"},
+				{IntField:300,StrField:"inner3"},
+			},
+		},
+	}); err == nil {
+		if !bytes.Equal(result, expected) {
+			t.Errorf("Bad marshal: expected\n----\n%s\n----\ngot\n----\n%s\n----\n", expected, result)
+		}
+	} else {
+		t.Fatal(err)
+	}
+}
+
+func TestUnmarshalMixedTypeArray(t *testing.T) {
+	type TestStruct struct {
+		ArrayField []interface{}
+	}
+
+	toml := []byte(`ArrayField = [3.14,100,true,"hello world",{Field = "inner1"},[{Field = "inner2"},{Field = "inner3"}]]
+`)
+
+	actual := TestStruct{}
+	expected := TestStruct{
+		ArrayField:[]interface{}{
+			3.14,
+			int64(100),
+			true,
+			"hello world",
+			map[string]interface{}{
+				"Field":"inner1",
+			},
+			[]map[string]interface{}{
+				{"Field":"inner2"},
+				{"Field":"inner3"},
+			},
+		},
+	}
+
+	if err := Unmarshal(toml, &actual); err == nil {
+		if !reflect.DeepEqual(actual, expected) {
+			t.Errorf("Bad unmarshal: expected %#v, got %#v", expected, actual)
+		}
+	} else {
+		t.Fatal(err)
+	}
+}
+
 func TestUnmarshalArray(t *testing.T) {
 	var tree *Tree
 	var err error

parser.go

@@ -427,7 +427,7 @@ Loop:
 
 func (p *tomlParser) parseArray() interface{} {
 	var array []interface{}
-	arrayType := reflect.TypeOf(nil)
+	arrayType := reflect.TypeOf(newTree())
 	for {
 		follow := p.peek()
 		if follow == nil || follow.typ == tokenEOF {
@@ -438,11 +438,8 @@ func (p *tomlParser) parseArray() interface{} {
 			break
 		}
 		val := p.parseRvalue()
-		if arrayType == nil {
-			arrayType = reflect.TypeOf(val)
-		}
 		if reflect.TypeOf(val) != arrayType {
-			p.raiseError(follow, "mixed types in array")
+			arrayType = nil
 		}
 		array = append(array, val)
 		follow = p.peek()
@@ -456,6 +453,12 @@ func (p *tomlParser) parseArray() interface{} {
 			p.getToken()
 		}
 	}
+
+	// if the array is a mixed-type array or its length is 0,
+	// don't convert it to a table array
+	if len(array) <= 0 {
+		arrayType = nil
+	}
 	// An array of Trees is actually an array of inline
 	// tables, which is a shorthand for a table array. If the
 	// array was not converted from []interface{} to []*Tree,

parser_test.go

@@ -488,18 +488,6 @@ func TestNestedEmptyArrays(t *testing.T) {
 	})
 }
 
-func TestArrayMixedTypes(t *testing.T) {
-	_, err := Load("a = [42, 16.0]")
-	if err.Error() != "(1, 10): mixed types in array" {
-		t.Error("Bad error message:", err.Error())
-	}
-
-	_, err = Load("a = [42, \"hello\"]")
-	if err.Error() != "(1, 11): mixed types in array" {
-		t.Error("Bad error message:", err.Error())
-	}
-}
-
 func TestArrayNestedStrings(t *testing.T) {
 	tree, err := Load("data = [ [\"gamma\", \"delta\"], [\"Foo\"] ]")
 	assertTree(t, tree, err, map[string]interface{}{
@@ -934,7 +922,7 @@ func TestTomlValueStringRepresentation(t *testing.T) {
 		{[]interface{}{"gamma", "delta"}, "[\"gamma\",\"delta\"]"},
 		{nil, ""},
 	} {
-		result, err := tomlValueStringRepresentation(item.Value, "", "", false)
+		result, err := tomlValueStringRepresentation(item.Value, "", "", OrderPreserve, false)
 		if err != nil {
 			t.Errorf("Test %d - unexpected error: %s", idx, err)
 		}

toml_testgen_test.go

@@ -5,21 +5,6 @@ import (
 	"testing"
 )
 
-func TestInvalidArrayMixedTypesArraysAndInts(t *testing.T) {
-	input := `arrays-and-ints =  [1, ["Arrays are not integers."]]`
-	testgenInvalid(t, input)
-}
-
-func TestInvalidArrayMixedTypesIntsAndFloats(t *testing.T) {
-	input := `ints-and-floats = [1, 1.1]`
-	testgenInvalid(t, input)
-}
-
-func TestInvalidArrayMixedTypesStringsAndInts(t *testing.T) {
-	input := `strings-and-ints = ["hi", 42]`
-	testgenInvalid(t, input)
-}
-
 func TestInvalidDatetimeMalformedNoLeads(t *testing.T) {
 	input := `no-leads = 1987-7-05T17:45:00Z`
 	testgenInvalid(t, input)

tomltree_write.go

@@ -103,7 +103,42 @@ func encodeTomlString(value string) string {
 	return b.String()
 }
 
-func tomlValueStringRepresentation(v interface{}, commented string, indent string, arraysOneElementPerLine bool) (string, error) {
+func tomlTreeStringRepresentation(t *Tree, ord marshalOrder) (string, error) {
+	var orderedVals []sortNode
+
+	switch ord {
+	case OrderPreserve:
+		orderedVals = sortByLines(t)
+	default:
+		orderedVals = sortAlphabetical(t)
+	}
+
+	stringBuffer := bytes.Buffer{}
+	stringBuffer.WriteString(`{`)
+	first := true
+	for i := range orderedVals {
+		v := t.values[orderedVals[i].key]
+		quotedKey := quoteKeyIfNeeded(orderedVals[i].key)
+		valueStr, err := tomlValueStringRepresentation(v, "", "", ord, false)
+		if err != nil {
+			return "", err
+		}
+		if first {
+			first = false
+		} else {
+			stringBuffer.WriteString(`,`)
+		}
+
+		stringBuffer.WriteString(quotedKey)
+		stringBuffer.WriteString(" = ")
+		stringBuffer.WriteString(valueStr)
+	}
+	stringBuffer.WriteString(`}`)
+
+	return stringBuffer.String(), nil
+}
+
+func tomlValueStringRepresentation(v interface{}, commented string, indent string, ord marshalOrder, arraysOneElementPerLine bool) (string, error) {
 	// this interface check is added to dereference the change made in the writeTo function.
 	// That change was made to allow this function to see formatting options.
 	tv, ok := v.(*tomlValue)
@@ -140,7 +175,7 @@ func tomlValueStringRepresentation(v interface{}, commented string, indent strin
 		return "\"" + encodeTomlString(value) + "\"", nil
 	case []byte:
 		b, _ := v.([]byte)
-		return tomlValueStringRepresentation(string(b), commented, indent, arraysOneElementPerLine)
+		return tomlValueStringRepresentation(string(b), commented, indent, ord, arraysOneElementPerLine)
 	case bool:
 		if value {
 			return "true", nil
@@ -154,6 +189,8 @@ func tomlValueStringRepresentation(v interface{}, commented string, indent strin
 		return value.String(), nil
 	case LocalTime:
 		return value.String(), nil
+	case *Tree:
+		return tomlTreeStringRepresentation(value, ord)
 	case nil:
 		return "", nil
 	}
@@ -164,7 +201,7 @@ func tomlValueStringRepresentation(v interface{}, commented string, indent strin
 		var values []string
 		for i := 0; i < rv.Len(); i++ {
 			item := rv.Index(i).Interface()
-			itemRepr, err := tomlValueStringRepresentation(item, commented, indent, arraysOneElementPerLine)
+			itemRepr, err := tomlValueStringRepresentation(item, commented, indent, ord, arraysOneElementPerLine)
 			if err != nil {
 				return "", err
 			}
@@ -368,7 +405,7 @@ func (t *Tree) writeToOrdered(w io.Writer, indent, keyspace string, bytesCount i
 			if parentCommented || t.commented || v.commented {
 				commented = "# "
 			}
-			repr, err := tomlValueStringRepresentation(v, commented, indent, arraysOneElementPerLine)
+			repr, err := tomlValueStringRepresentation(v, commented, indent, ord, arraysOneElementPerLine)
 			if err != nil {
 				return bytesCount, err
 			}