errors

func As ¶

func As(err error, target interface{}) bool

As finds the first error in err's chain that matches target, and if so, sets target to that error value and returns true. Otherwise, it returns false.

The chain consists of err itself followed by the sequence of errors obtained by repeatedly calling Unwrap.

An error matches target if the error's concrete value is assignable to the value pointed to by target, or if the error has a method As(interface{}) bool such that As(target) returns true. In the latter case, the As method is responsible for setting target.

An error type might provide an As method so it can be treated as if it were a a different error type.

As panics if target is not a non-nil pointer to either a type that implements error, or to any interface type.

func CallDetail ¶

func CallDetail(msg []byte, fn interface{}, args ...interface{}) []byte

CallDetail print a function call shortly.

func Err ¶

func Err(err error) error

Err returns the cause error.

func Is ¶

func Is(err, target error) bool

Is reports whether any error in err's chain matches target.

The chain consists of err itself followed by the sequence of errors obtained by repeatedly calling Unwrap.

An error is considered to match a target if it is equal to that target or if it implements a method Is(error) bool such that Is(target) returns true.

An error type might provide an Is method so it can be treated as equivalent to an existing error. For example, if MyError defines

func (m MyError) Is(target error) bool { return target == os.ErrExist }

then Is(MyError{}, os.ErrExist) returns true. See syscall.Errno.Is for an example in the standard library.

func IsNotFound ¶

func IsNotFound(err error) bool

IsNotFound unwraps err and checks it is a *NotFound object or not.

func New ¶

func New(msg string) error

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 Summary ¶

func Summary(err error) string

Summary returns summary of specified error.

func Unwrap ¶

func Unwrap(err error) error

Unwrap returns the result of calling the Unwrap method on err, if err's type contains an Unwrap method returning error. Otherwise, Unwrap returns nil.