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Document that errors returned by Join always implement Unwrap []error.
Explicitly state that Unwrap does not unwrap errors
with an Unwrap() []error method.
Change-Id: Id610345dcf43ca54a9dde157e56c5815c5112073
GitHub-Last-Rev: 7a0ec450bd
GitHub-Pull-Request: golang/go#59301
Reviewed-on: https://go-review.googlesource.com/c/go/+/480021
Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com>
Auto-Submit: Emmanuel Odeke <emmanuel@orijtech.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
53 lines
1.1 KiB
Go
53 lines
1.1 KiB
Go
// Copyright 2022 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package errors
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// Join returns an error that wraps the given errors.
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// Any nil error values are discarded.
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// Join returns nil if every value in errs is nil.
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// The error formats as the concatenation of the strings obtained
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// by calling the Error method of each element of errs, with a newline
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// between each string.
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//
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// A non-nil error returned by Join implements the Unwrap() []error method.
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func Join(errs ...error) error {
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n := 0
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for _, err := range errs {
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if err != nil {
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n++
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}
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}
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if n == 0 {
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return nil
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}
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e := &joinError{
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errs: make([]error, 0, n),
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}
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for _, err := range errs {
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if err != nil {
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e.errs = append(e.errs, err)
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}
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}
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return e
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}
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type joinError struct {
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errs []error
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}
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func (e *joinError) Error() string {
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var b []byte
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for i, err := range e.errs {
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if i > 0 {
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b = append(b, '\n')
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}
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b = append(b, err.Error()...)
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}
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return string(b)
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}
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func (e *joinError) Unwrap() []error {
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return e.errs
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}
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