Imports #
"unsafe"
"internal/reflectlite"
errors
Imports
Constants & Variables
ErrUnsupported var #
ErrUnsupported indicates that a requested operation cannot be performed, because it is unsupported. For example, a call to [os.Link] when using a file system that does not support hard links. Functions and methods should not return this error but should instead return an error including appropriate context that satisfies errors.Is(err, errors.ErrUnsupported) either by directly wrapping ErrUnsupported or by implementing an [Is] method. Functions and methods should document the cases in which an error wrapping this will be returned.
var ErrUnsupported = *ast.CallExprerrorType var #
var errorType = *ast.CallExprStructs
errorString struct #
errorString is a trivial implementation of error.
type errorString struct {
s string
}joinError struct #
type joinError struct {
errs []error
}Functions
As function #
As finds the first error in err's tree that matches target, and if one is found, sets target to that error value and returns true. Otherwise, it returns false. The tree consists of err itself, followed by the errors obtained by repeatedly calling its Unwrap() error or Unwrap() []error method. When err wraps multiple errors, As examines err followed by a depth-first traversal of its children. 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(any) 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 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 As(err error, target any) boolError method #
func (e *errorString) Error() stringError method #
func (e *joinError) Error() stringIs function #
Is reports whether any error in err's tree matches target. The tree consists of err itself, followed by the errors obtained by repeatedly calling its Unwrap() error or Unwrap() []error method. When err wraps multiple errors, Is examines err followed by a depth-first traversal of its children. 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 == fs.ErrExist } then Is(MyError{}, fs.ErrExist) returns true. See [syscall.Errno.Is] for an example in the standard library. An Is method should only shallowly compare err and the target and not call [Unwrap] on either.
func Is(err error, target error) boolJoin function #
Join returns an error that wraps the given errors. Any nil error values are discarded. Join returns nil if every value in errs is nil. The error formats as the concatenation of the strings obtained by calling the Error method of each element of errs, with a newline between each string. A non-nil error returned by Join implements the Unwrap() []error method.
func Join(errs ...error) errorNew function #
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) errorUnwrap method #
func (e *joinError) Unwrap() []errorUnwrap function #
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. Unwrap only calls a method of the form "Unwrap() error". In particular Unwrap does not unwrap errors returned by [Join].
func Unwrap(err error) erroras function #
func as(err error, target any, targetVal reflectlite.Value, targetType reflectlite.Type) boolis function #
func is(err error, target error, targetComparable bool) boolGenerated with Arrow