Add slices package

slices/slices.go

@@ -0,0 +1,57 @@
+package slices
+
+import (
+	"reflect"
+
+	errors "golang.org/x/xerrors"
+)
+
+type PtrSlice struct {
+	slice   reflect.Value
+	current interface{}
+	t       reflect.Type
+	idx     int
+	length  int
+}
+
+func NewPtrSlice(s interface{}) (*PtrSlice, error) {
+	ps := &PtrSlice{}
+	ps.t = reflect.TypeOf(s)
+	if ps.t.Kind() != reflect.Slice {
+		return nil, errors.New("Attempted to create a PtrSlice from non-Slice")
+	}
+	ps.slice = reflect.ValueOf(s)
+	ps.length = ps.slice.Len()
+	ps.idx = 0
+	ps.current = ps.slice.Index(ps.idx).Interface()
+	return ps, nil
+}
+
+func MustPtrSlice(s interface{}) *PtrSlice {
+	ps, err := NewPtrSlice(s)
+	if err != nil {
+		panic(err)
+	}
+	return ps
+}
+
+func (ps *PtrSlice) Val() interface{} {
+	return ps.current
+}
+
+func (ps *PtrSlice) Incr() {
+	ps.idx++
+	ps.current = ps.slice.Index(ps.idx).Interface()
+}
+
+func (ps *PtrSlice) Len() int {
+	return ps.length
+}
+
+func (ps *PtrSlice) Offset(offset int) interface{} {
+	return ps.slice.Index(ps.idx + offset).Interface()
+}
+
+func (ps *PtrSlice) Get(idx int) interface{} {
+	return ps.slice.Index(idx).Interface()
+}