README
¶
errors
errors provides utility routines for working with errors that are compatible with go 1.13+ and for annotating errors with location and other information.
It currently provides:
errors.Mwhich can be used to store multiple error values.errors.Mis thread safe.
errs := errors.M{}
...
errs.Append(fn(a))
...
errs.Append(fn(b))
...
err := errs.Err()
errors.Caller,errors.Annotateanderrors.AnnotateAllwhich can be used to annotate an existing error with location information on the caller or an arbitrary string respectively.
err := errors.Caller(os.ErrNotExist)
fmt.Printf("%v\n", err)
fmt.Printf("%v\n", errors.Unwrap(err))
// Output:
// errors/caller_test.go:17: file does not exist
// file does not exist
Documentation
¶
Overview ¶
Package errors provides utility routines for working with errors that are compatible with go 1.13+ and for annotating errors with location and other information. It provides errors.M which can be used to collect and work with multiple errors in a thread safe manner. It also provides convenience routines for annotating existing errors with caller and other information.
errs := errors.M{}
errs.Append(fn(a))
errs.Append(fn(b))
err := errs.Err()
Annotations, can be added as follows:
err := errors.Caller(os.ErrNotExist)
Where:
fmt.Printf("%v\n", err)
fmt.Printf("%v\n", errors.Unwrap(err))
Would produce:
errors/caller_test.go:17: file does not exist file does not exist
Annotated errors can be passed to errors.M:
errs := errors.M{}
errs.Append(errors.Caller(fn(a)))
errs.Append(errors.Caller(fn(b)))
err := errs.Err()
Index ¶
- func Annotate(annotation string, err error) error
- func AnnotateAll(annotation string, errs ...error) []error
- func As(err error, target interface{}) bool
- func Caller(err error) error
- func CallerAll(err ...error) []error
- func FileLocation(depth, nameLen int) string
- func Is(err, target error) bool
- func New(m string) error
- func Unwrap(err error) error
- type M
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Annotate ¶ added in v0.0.3
Annotate returns an error representing the original error and the supplied annotation.
func AnnotateAll ¶ added in v0.0.3
AnnotateAll returns a slice of errors representing the original errors and the supplied annotation.
func Caller ¶ added in v0.0.3
Caller returns an error annotated with the location of its immediate caller.
Example ¶
package main
import (
"fmt"
"os"
"cloudeng.io/errors"
)
func main() {
err := errors.Caller(os.ErrNotExist)
fmt.Printf("%v\n", err)
fmt.Printf("%v\n", errors.Unwrap(err))
}
Output: errors/caller_test.go:17: file does not exist file does not exist
func CallerAll ¶ added in v0.0.4
CallerAll returns a slice conntaing annotated versions of all of the supplied errors.
func FileLocation ¶ added in v0.0.3
FileLocation returns the callers location as a filepath and line number. Depth follows the convention for runtime.Caller. The filepath is the trailing nameLen components of the filename returned by runtime.Caller. A nameLen of 2 is generally the best compromise between brevity and precision since it includes the enclosing directory component as well as the filename.
Example ¶
package main
import (
"fmt"
"cloudeng.io/errors"
)
func main() {
fmt.Println(errors.FileLocation(1, 1))
fmt.Println(errors.FileLocation(1, 2))
}
Output: caller_test.go:38 errors/caller_test.go:39
Types ¶
type M ¶
type M struct {
// contains filtered or unexported fields
}
M represents multiple errors. It is thread safe. Typical usage is:
errs := errors.M{} ... errs.Append(err) ... return errs.Err()
Example ¶
package main
import (
"fmt"
"os"
"cloudeng.io/errors"
)
func main() {
m := &errors.M{}
fmt.Println(m.Err())
m.Append(os.ErrExist)
m.Append(os.ErrInvalid)
fmt.Println(m.Err())
}
Output: <nil> --- 1 of 2 errors file already exists --- 2 of 2 errors invalid argument
Example (Caller) ¶
package main
import (
"fmt"
"os"
"cloudeng.io/errors"
)
func main() {
m := &errors.M{}
m.Append(errors.Caller(os.ErrExist))
m.Append(errors.Caller(os.ErrInvalid))
fmt.Println(m.Err())
}
Output: --- 1 of 2 errors errors/caller_test.go:27: file already exists --- 2 of 2 errors errors/caller_test.go:28: invalid argument
Source Files