structure: add ToSlice() , closes #3

README.md

@@ -32,10 +32,21 @@ if err != nil {
 	panic(err)
 }
 
-fmt.Printf("%#v", m)
 // prints: map[string]interface {}{"Name":"Arslan", "ID":123456, "Enabled":true}
+fmt.Printf("%#v", m)
 ```
 
+```go
+// convert it to a []interface{}. Slice values are sorted according to the
+// field names.
+m, err := structure.ToSlice(s)
+if err != nil {
+	panic(err)
+}
+
+// prints: []interface {}{true, 123456, "Arslan"}
+fmt.Printf("%#v", m)
+
 ```go
 // check if it's a struct or a pointer to struct
 if structure.IsStruct(s) {

structure.go

@@ -4,6 +4,7 @@ package structure
 import (
 	"errors"
 	"reflect"
+	"sort"
 )
 
 // ErrNotStruct is returned when the passed value is not a struct
@@ -13,11 +14,11 @@ var ErrNotStruct = errors.New("not struct")
 // string is the struct fieldname but this can be changed by defining a
 // "structure" tag key if needed. Note that only exported fields of a struct
 // can be accessed, non exported fields will be neglected.
-func ToMap(in interface{}) (map[string]interface{}, error) {
+func ToMap(s interface{}) (map[string]interface{}, error) {
 	out := make(map[string]interface{})
 
-	t := reflect.TypeOf(in)
-	v := reflect.ValueOf(in)
+	t := reflect.TypeOf(s)
+	v := reflect.ValueOf(s)
 
 	// if pointer get the underlying element≤
 	if t.Kind() == reflect.Ptr {
@@ -50,10 +51,38 @@ func ToMap(in interface{}) (map[string]interface{}, error) {
 	return out, nil
 }
 
+// ToSlice converts a struct's field values to a []interface{}. Values are
+// inserted and sorted according to the field names. Note that only exported
+// fields of a struct can be accessed, non exported fields  will be neglected.
+func ToSlice(s interface{}) ([]interface{}, error) {
+	m, err := ToMap(s)
+	if err != nil {
+		return nil, err
+	}
+
+	keys := make([]string, len(m))
+	count := 0
+	for k := range m {
+		keys[count] = k
+		count++
+	}
+
+	sort.Strings(keys)
+
+	t := make([]interface{}, len(m))
+
+	for i, key := range keys {
+		t[i] = m[key]
+	}
+
+	return t, nil
+
+}
+
 // IsStruct returns true if the given variable is a struct or a pointer to
 // struct.
-func IsStruct(strct interface{}) bool {
-	t := reflect.TypeOf(strct)
+func IsStruct(s interface{}) bool {
+	t := reflect.TypeOf(s)
 	if t.Kind() == reflect.Ptr {
 		t = t.Elem()
 	}

structure_example_test.go

@@ -58,3 +58,27 @@ func ExampleToMap_tags() {
 	// false
 
 }
+
+func ExampleToSlice() {
+	type Server struct {
+		Name    string
+		ID      int32
+		Enabled bool
+	}
+
+	s := &Server{
+		Name:    "Fatih",
+		ID:      135790,
+		Enabled: false,
+	}
+
+	m, err := ToSlice(s)
+	if err != nil {
+		panic(err)
+	}
+
+	// note that the output is sorted according to the field names
+	fmt.Printf("%#v\n", m)
+	// Output:
+	// []interface {}{false, 135790, "Fatih"}
+}

structure_test.go

@@ -105,3 +105,36 @@ func TestStruct(t *testing.T) {
 	}
 
 }
+
+func TestToSlice(t *testing.T) {
+	var T = struct {
+		A string
+		B int
+		C bool
+	}{
+		A: "a-value",
+		B: 2,
+		C: true,
+	}
+
+	s, err := ToSlice(T)
+	if err != nil {
+		t.Error(err)
+	}
+
+	inSlice := func(val interface{}) bool {
+		for _, v := range s {
+			if reflect.DeepEqual(v, val) {
+				return true
+			}
+		}
+
+		return false
+	}
+
+	for _, val := range []interface{}{"a-value", 2, true} {
+		if !inSlice(val) {
+			t.Errorf("ToSlice should have the value %v", val)
+		}
+	}
+}