diff options
Diffstat (limited to 'vendor/go.uber.org/multierr/error.go')
-rw-r--r-- | vendor/go.uber.org/multierr/error.go | 58 |
1 files changed, 53 insertions, 5 deletions
diff --git a/vendor/go.uber.org/multierr/error.go b/vendor/go.uber.org/multierr/error.go index de6ce473..04eb9618 100644 --- a/vendor/go.uber.org/multierr/error.go +++ b/vendor/go.uber.org/multierr/error.go @@ -1,4 +1,4 @@ -// Copyright (c) 2017 Uber Technologies, Inc. +// Copyright (c) 2019 Uber Technologies, Inc. // // Permission is hereby granted, free of charge, to any person obtaining a copy // of this software and associated documentation files (the "Software"), to deal @@ -33,7 +33,7 @@ // If only two errors are being combined, the Append function may be used // instead. // -// err = multierr.Combine(reader.Close(), writer.Close()) +// err = multierr.Append(reader.Close(), writer.Close()) // // This makes it possible to record resource cleanup failures from deferred // blocks with the help of named return values. @@ -99,8 +99,6 @@ var ( // Separator for single-line error messages. _singlelineSeparator = []byte("; ") - _newline = []byte("\n") - // Prefix for multi-line messages _multilinePrefix = []byte("the following errors occurred:") @@ -132,7 +130,7 @@ type errorGroup interface { } // Errors returns a slice containing zero or more errors that the supplied -// error is composed of. If the error is nil, the returned slice is empty. +// error is composed of. If the error is nil, a nil slice is returned. // // err := multierr.Append(r.Close(), w.Close()) // errors := multierr.Errors(err) @@ -399,3 +397,53 @@ func Append(left error, right error) error { errors := [2]error{left, right} return fromSlice(errors[0:]) } + +// AppendInto appends an error into the destination of an error pointer and +// returns whether the error being appended was non-nil. +// +// var err error +// multierr.AppendInto(&err, r.Close()) +// multierr.AppendInto(&err, w.Close()) +// +// The above is equivalent to, +// +// err := multierr.Append(r.Close(), w.Close()) +// +// As AppendInto reports whether the provided error was non-nil, it may be +// used to build a multierr error in a loop more ergonomically. For example: +// +// var err error +// for line := range lines { +// var item Item +// if multierr.AppendInto(&err, parse(line, &item)) { +// continue +// } +// items = append(items, item) +// } +// +// Compare this with a verison that relies solely on Append: +// +// var err error +// for line := range lines { +// var item Item +// if parseErr := parse(line, &item); parseErr != nil { +// err = multierr.Append(err, parseErr) +// continue +// } +// items = append(items, item) +// } +func AppendInto(into *error, err error) (errored bool) { + if into == nil { + // We panic if 'into' is nil. This is not documented above + // because suggesting that the pointer must be non-nil may + // confuse users into thinking that the error that it points + // to must be non-nil. + panic("misuse of multierr.AppendInto: into pointer must not be nil") + } + + if err == nil { + return false + } + *into = Append(*into, err) + return true +} |