github.com/mailgun/holster/v4@v4.20.0/errors/go113.go (about) 1 //go:build go1.13 2 // +build go1.13 3 4 package errors 5 6 import ( 7 stderrors "errors" 8 ) 9 10 // Is reports whether any error in err's chain matches target. 11 // 12 // The chain consists of err itself followed by the sequence of errors obtained by 13 // repeatedly calling Unwrap. 14 // 15 // An error is considered to match a target if it is equal to that target or if 16 // it implements a method Is(error) bool such that Is(target) returns true. 17 func Is(err, target error) bool { return stderrors.Is(err, target) } 18 19 // As finds the first error in err's chain that matches target, and if so, sets 20 // target to that error value and returns true. 21 // 22 // The chain consists of err itself followed by the sequence of errors obtained by 23 // repeatedly calling Unwrap. 24 // 25 // An error matches target if the error's concrete value is assignable to the value 26 // pointed to by target, or if the error has a method As(interface{}) bool such that 27 // As(target) returns true. In the latter case, the As method is responsible for 28 // setting target. 29 // 30 // As will panic if target is not a non-nil pointer to either a type that implements 31 // error, or to any interface type. As returns false if err is nil. 32 func As(err error, target interface{}) bool { return stderrors.As(err, target) } 33 34 // Unwrap returns the result of calling the Unwrap method on err, if err's 35 // type contains an Unwrap method returning error. 36 // Otherwise, Unwrap returns nil. 37 func Unwrap(err error) error { 38 return stderrors.Unwrap(err) 39 }