diff options
Diffstat (limited to 'vendor/github.com/pkg/errors/errors.go')
| -rw-r--r-- | vendor/github.com/pkg/errors/errors.go | 269 |
1 files changed, 0 insertions, 269 deletions
diff --git a/vendor/github.com/pkg/errors/errors.go b/vendor/github.com/pkg/errors/errors.go deleted file mode 100644 index 842ee804..00000000 --- a/vendor/github.com/pkg/errors/errors.go +++ /dev/null @@ -1,269 +0,0 @@ -// Package errors provides simple error handling primitives. -// -// The traditional error handling idiom in Go is roughly akin to -// -// if err != nil { -// return err -// } -// -// which applied recursively up the call stack results in error reports -// without context or debugging information. The errors package allows -// programmers to add context to the failure path in their code in a way -// that does not destroy the original value of the error. -// -// Adding context to an error -// -// The errors.Wrap function returns a new error that adds context to the -// original error by recording a stack trace at the point Wrap is called, -// and the supplied message. For example -// -// _, err := ioutil.ReadAll(r) -// if err != nil { -// return errors.Wrap(err, "read failed") -// } -// -// If additional control is required the errors.WithStack and errors.WithMessage -// functions destructure errors.Wrap into its component operations of annotating -// an error with a stack trace and an a message, respectively. -// -// Retrieving the cause of an error -// -// Using errors.Wrap constructs a stack of errors, adding context to the -// preceding error. Depending on the nature of the error it may be necessary -// to reverse the operation of errors.Wrap to retrieve the original error -// for inspection. Any error value which implements this interface -// -// type causer interface { -// Cause() error -// } -// -// can be inspected by errors.Cause. errors.Cause will recursively retrieve -// the topmost error which does not implement causer, which is assumed to be -// the original cause. For example: -// -// switch err := errors.Cause(err).(type) { -// case *MyError: -// // handle specifically -// default: -// // unknown error -// } -// -// causer interface is not exported by this package, but is considered a part -// of stable public API. -// -// Formatted printing of errors -// -// All error values returned from this package implement fmt.Formatter and can -// be formatted by the fmt package. The following verbs are supported -// -// %s print the error. If the error has a Cause it will be -// printed recursively -// %v see %s -// %+v extended format. Each Frame of the error's StackTrace will -// be printed in detail. -// -// Retrieving the stack trace of an error or wrapper -// -// New, Errorf, Wrap, and Wrapf record a stack trace at the point they are -// invoked. This information can be retrieved with the following interface. -// -// type stackTracer interface { -// StackTrace() errors.StackTrace -// } -// -// Where errors.StackTrace is defined as -// -// type StackTrace []Frame -// -// The Frame type represents a call site in the stack trace. Frame supports -// the fmt.Formatter interface that can be used for printing information about -// the stack trace of this error. For example: -// -// if err, ok := err.(stackTracer); ok { -// for _, f := range err.StackTrace() { -// fmt.Printf("%+s:%d", f) -// } -// } -// -// stackTracer interface is not exported by this package, but is considered a part -// of stable public API. -// -// See the documentation for Frame.Format for more details. -package errors - -import ( - "fmt" - "io" -) - -// New returns an error with the supplied message. -// New also records the stack trace at the point it was called. -func New(message string) error { - return &fundamental{ - msg: message, - stack: callers(), - } -} - -// Errorf formats according to a format specifier and returns the string -// as a value that satisfies error. -// Errorf also records the stack trace at the point it was called. -func Errorf(format string, args ...interface{}) error { - return &fundamental{ - msg: fmt.Sprintf(format, args...), - stack: callers(), - } -} - -// fundamental is an error that has a message and a stack, but no caller. -type fundamental struct { - msg string - *stack -} - -func (f *fundamental) Error() string { return f.msg } - -func (f *fundamental) Format(s fmt.State, verb rune) { - switch verb { - case 'v': - if s.Flag('+') { - io.WriteString(s, f.msg) - f.stack.Format(s, verb) - return - } - fallthrough - case 's': - io.WriteString(s, f.msg) - case 'q': - fmt.Fprintf(s, "%q", f.msg) - } -} - -// WithStack annotates err with a stack trace at the point WithStack was called. -// If err is nil, WithStack returns nil. -func WithStack(err error) error { - if err == nil { - return nil - } - return &withStack{ - err, - callers(), - } -} - -type withStack struct { - error - *stack -} - -func (w *withStack) Cause() error { return w.error } - -func (w *withStack) Format(s fmt.State, verb rune) { - switch verb { - case 'v': - if s.Flag('+') { - fmt.Fprintf(s, "%+v", w.Cause()) - w.stack.Format(s, verb) - return - } - fallthrough - case 's': - io.WriteString(s, w.Error()) - case 'q': - fmt.Fprintf(s, "%q", w.Error()) - } -} - -// Wrap returns an error annotating err with a stack trace -// at the point Wrap is called, and the supplied message. -// If err is nil, Wrap returns nil. -func Wrap(err error, message string) error { - if err == nil { - return nil - } - err = &withMessage{ - cause: err, - msg: message, - } - return &withStack{ - err, - callers(), - } -} - -// Wrapf returns an error annotating err with a stack trace -// at the point Wrapf is call, and the format specifier. -// If err is nil, Wrapf returns nil. -func Wrapf(err error, format string, args ...interface{}) error { - if err == nil { - return nil - } - err = &withMessage{ - cause: err, - msg: fmt.Sprintf(format, args...), - } - return &withStack{ - err, - callers(), - } -} - -// WithMessage annotates err with a new message. -// If err is nil, WithMessage returns nil. -func WithMessage(err error, message string) error { - if err == nil { - return nil - } - return &withMessage{ - cause: err, - msg: message, - } -} - -type withMessage struct { - cause error - msg string -} - -func (w *withMessage) Error() string { return w.msg + ": " + w.cause.Error() } -func (w *withMessage) Cause() error { return w.cause } - -func (w *withMessage) Format(s fmt.State, verb rune) { - switch verb { - case 'v': - if s.Flag('+') { - fmt.Fprintf(s, "%+v\n", w.Cause()) - io.WriteString(s, w.msg) - return - } - fallthrough - case 's', 'q': - io.WriteString(s, w.Error()) - } -} - -// Cause returns the underlying cause of the error, if possible. -// An error value has a cause if it implements the following -// interface: -// -// type causer interface { -// Cause() error -// } -// -// If the error does not implement Cause, the original error will -// be returned. If the error is nil, nil will be returned without further -// investigation. -func Cause(err error) error { - type causer interface { - Cause() error - } - - for err != nil { - cause, ok := err.(causer) - if !ok { - break - } - err = cause.Cause() - } - return err -} |