common/prpc, tools/cmd/cproto: prpc client

common/errors/wrap.go

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package errors
+
+// Wrap wraps an error.
+type Wrap interface {
+        // InnerError returns the wrapped error.
+        InnerError() error
+}
+
+// Unwrap returns the inner error of err.
+// Returns nil if err does not wrap anything or err is nil.
+func Unwrap(err error) error {
+        if wrap, ok := err.(Wrap); ok {
+                return wrap.InnerError()
+        }
+        return nil
+}
+
+// UnwrapAll unwraps a wrapped error recursively.
+// Returns nil iff err is nil.
+func UnwrapAll(err error) error {
+        for {
+                inner := Unwrap(err)
+                if inner == nil {
+                        break
+                }
+                err = inner
+        }
+        return err
+}