errors

Stack errors for golang

Package errors provides simple error handling primitives.

go get github.com/pharosnet/errors

The traditional error handling idiom in Go is roughly akin to

if err != nil {
        return err
}

which applied recursively up the call stack results in error reports without context or debugging information. The errors package allows programmers to add context to the failure path in their code in a way that does not destroy the original value of the error.

Adding context to an error

The errors.Wrap function returns a new error that adds context to the original error. For example

_, err := ioutil.ReadAll(r)
if err != nil {
        return errors.Wrap(err)
}

Retrieving the cause of an error

Using errors.Wrap constructs a stack of errors, adding context to the preceding error. Depending on the nature of the error it may be necessary to reverse the operation of errors.Wrap to retrieve the original error for inspection. Any error value which implements this interface can be inspected by errors.Cause.

type Errors interface {
	Error() string
	Cause() error
	OccurTime() time.Time
	PCS() []uintptr
	Contains(error) bool
	Format(fmt.State, rune)
}

errors.Contains will search target in error which implements Errors, For example:

    e1 := io.EOF
    e2 := errors.With(e1, "error2")
    e3 := errors.Withf(e2, "%s", "error3")
     
    if errors.Contains(e3, e2) {
            // TODO .. 
    }
        
    if errors.Contains(e3, e1) {
        // TODO ...
    }

    // full format
    fmt.Println(fmt.Sprintf("%+v", e3))

    // json format
    fmt.Println(fmt.Sprintf("%-v", e3))

Read the examples for more usages.

Read the package documentation for more information.

Contributing

We welcome pull requests, bug fixes and issue reports. With that said, the bar for adding new symbols to this package is intentionally set high.

Before proposing a change, please discuss your change by raising an issue.

License

GNU GENERAL PUBLIC LICENSE(v3)