package errors

import "emperror.dev/errors"

Package errors is a drop-in replacement for the standard errors package and github.com/pkg/errors.

Index ¶

• func As(err error, target interface{}) bool
• func Cause(err error) error
• func Errorf(format string, a ...interface{}) error
• func Is(err, target error) bool
• func New(message string) error
• func NewPlain(message string) error
• func Unwrap(err error) error
• func WithMessage(err error, message string) error
• func WithMessagef(err error, format string, a ...interface{}) error
• func WithStack(err error) error
• func WithStackDepth(err error, depth int) error
• func Wrap(err error, message string) error
• func Wrapf(err error, format string, a ...interface{}) error
• type Frame
• type StackTrace

Examples ¶

• As

Functions ¶

func As ¶

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

As finds the first error in err's chain that matches the type to which target points, and if so, sets the target to its value and returns true. An error matches a type if it is assignable to the target type, or if it has a method As(interface{}) bool such that As(target) returns true. As will panic if target is not a non-nil pointer to a type which implements error or is of interface type.

The As method should set the target to its value and return true if err matches the type to which target points.

package main

import (
	"fmt"
	"os"

	"emperror.dev/errors"
)

func main() {
	if _, err := os.Open("non-existing"); err != nil {
		var pathError *os.PathError
		if errors.As(err, &pathError) {
			fmt.Println("Failed at path:", pathError.Path)
		} else {
			fmt.Println(err)
		}
	}

}

Failed at path: non-existing

func Cause ¶

func Cause(err error) error

Cause returns the last error (root cause) in an error chain. If the error has no cause, it is returned directly.

It supports both Go 1.13 errors.Wrapper and github.com/pkg/errors.Causer interfaces (the former takes precedence).

func Errorf ¶

func Errorf(format string, a ...interface{}) error

Errorf returns a new error with a formatted message and annotated with stack trace at the point Errorf is called.

func Is ¶

func Is(err, target error) bool

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

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.

func New ¶

func New(message string) error

New returns a new error annotated with stack trace at the point New is called.

func NewPlain ¶

func NewPlain(message string) error

NewPlain returns a simple error without any annotated context, like stack trace. Useful for creating sentinel errors and in testing.

func Unwrap ¶

func Unwrap(err error) error

Unwrap returns the result of calling the Unwrap method on err, if err implements Unwrap. Otherwise, Unwrap returns nil.

It supports both Go 1.13 Unwrap and github.com/pkg/errors.Causer interfaces (the former takes precedence).

func WithMessage ¶

func WithMessage(err error, message string) error

WithMessage annotates err with a new message. If err is nil, WithMessage returns nil.

func WithMessagef ¶

func WithMessagef(err error, format string, a ...interface{}) error

WithMessagef annotates err with the format specifier. If err is nil, WithMessagef returns nil.

func WithStack ¶

func WithStack(err error) error

WithStack annotates err with a stack trace at the point WithStack was called. If err is nil, WithStack returns nil.

func WithStackDepth ¶

func WithStackDepth(err error, depth int) error

WithStackDepth annotates err with a stack trace at the given call depth. Zero identifies the caller of WithStackDepth itself. If err is nil, WithStackDepth returns nil.

func Wrap ¶

func Wrap(err error, message string) 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 Wrapf ¶

func Wrapf(err error, format string, a ...interface{}) error

Wrapf returns an error annotating err with a stack trace at the point Wrapf is called, and the format specifier. If err is nil, Wrapf returns nil.

Types ¶

type Frame ¶

type Frame = errors.Frame

Frame represents a program counter inside a stack frame. For historical reasons if Frame is interpreted as a uintptr its value represents the program counter + 1.

It is an alias of the same type in github.com/pkg/errors.

type StackTrace ¶

type StackTrace = errors.StackTrace

StackTrace is stack of Frames from innermost (newest) to outermost (oldest).

It is an alias of the same type in github.com/pkg/errors.

Source Files ¶

errors.go stack.go wrap.go wrap_go1_13.go

Directories ¶