Adding upstream version 1.17.13.upstream/1.17.13upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 69 insertions, 0 deletions

diff --git a/src/errors/errors.go b/src/errors/errors.go
new file mode 100644
index 0000000..f2fabac
--- /dev/null
+++ b/src/errors/errors.go
@@ -0,0 +1,69 @@
+// Copyright 2011 The Go 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 implements functions to manipulate errors.
+//
+// The New function creates errors whose only content is a text message.
+//
+// The Unwrap, Is and As functions work on errors that may wrap other errors.
+// An error wraps another error if its type has the method
+//
+//	Unwrap() error
+//
+// If e.Unwrap() returns a non-nil error w, then we say that e wraps w.
+//
+// Unwrap unpacks wrapped errors. If its argument's type has an
+// Unwrap method, it calls the method once. Otherwise, it returns nil.
+//
+// A simple way to create wrapped errors is to call fmt.Errorf and apply the %w verb
+// to the error argument:
+//
+//	errors.Unwrap(fmt.Errorf("... %w ...", ..., err, ...))
+//
+// returns err.
+//
+// Is unwraps its first argument sequentially looking for an error that matches the
+// second. It reports whether it finds a match. It should be used in preference to
+// simple equality checks:
+//
+//	if errors.Is(err, fs.ErrExist)
+//
+// is preferable to
+//
+//	if err == fs.ErrExist
+//
+// because the former will succeed if err wraps fs.ErrExist.
+//
+// As unwraps its first argument sequentially looking for an error that can be
+// assigned to its second argument, which must be a pointer. If it succeeds, it
+// performs the assignment and returns true. Otherwise, it returns false. The form
+//
+//	var perr *fs.PathError
+//	if errors.As(err, &perr) {
+//		fmt.Println(perr.Path)
+//	}
+//
+// is preferable to
+//
+//	if perr, ok := err.(*fs.PathError); ok {
+//		fmt.Println(perr.Path)
+//	}
+//
+// because the former will succeed if err wraps an *fs.PathError.
+package errors
+
+// New returns an error that formats as the given text.
+// Each call to New returns a distinct error value even if the text is identical.
+func New(text string) error {
+	return &errorString{text}
+}
+
+// errorString is a trivial implementation of error.
+type errorString struct {
+	s string
+}
+
+func (e *errorString) Error() string {
+	return e.s
+}