README
¶
README
An errors recorder package
This design supplements and implements the errors interface of golang, Used to provide information such as the cause and file location of the error when it occurs, in order to restore the happened scene.
Due to the large amount of data contained in this erroneous design, it is necessary to pay attention to the frequency of calls to avoid affecting system efficiency.
- Example
package main
import "github.com/gwaylib/errors"
func fn1(a int) error {
if a == 0 {
// return a common no data error
return errors.ErrNoData.As(a)
}
// other errors with fault position
return errors.New("not implements").As(a)
}
func fn2(b int) error {
// call and set the error position, do nothing if 'fn1' return nil
return errors.As(fn1(b))
}
func main() {
err := fn2(2)
if err != nil {
// Attention, errors.ErrNoData == err may not necessarily hold, the Equal method should be used
if !errors.ErrNoData.Equal(err) {
panic(err)
}
fmt.Println(err)
}
}
- Analyze errors position information
Output：
["test",["errors_test.go:90#errors.TestAs"],["errors_test.go:95#errors.TestAs",123,456]]
Decode:
ErrData[0] -- the input of errors.New()
ErrData[1:] -- position information
ErrData[1][0] -- the position information when first calling 'As'
ErrData[1][1:] -- the args when first calling 'As'
Error handling suggestions
*) Prioritize handling errors before handling normal logic, as errors are less likely to be ignored and make the program more robust; *) Unless the error handling result is clearly defined, errors should always be returned to the caller; *) If it is not possible to return to the caller, user prompts or logs should be provided instead of discarding errors to fully understand what has happened in the program; *) Normal logic should not be written in if conditions to ensure good text indentation and reading of the code;
// Suggest
rows, err := db.Query(...)
if err != nil{
return errors.As(err)
}
defer rows.Close()
...
// Unsuggest
rows, err := db.Query(...)
if err == nil{
defer rows.Close()
// ...
} else {
// handle error or not
}
*) Define errors within a small scope, otherwise there is a risk of diffusion
func Get() (err error){
// Suggest
rows, err := db.Query(...)
if err != nil{
return errors.As(err)
}
defer rows.Close()
if err := rows.Scan(...); err != nil{
// ...
}
...
}
Documentation
¶
Overview ¶
错误记录器 error recorder
本设计补充并实现了系统的error接口。 This design complements and implements the error interface of the go package.
用于发生错误时附带发生错误的原因、位置等信息以便还原现场。 It can be used to restore the scene with the information of the cause and location of the error when it occurs.
因本错误设计含有比较大的数据量信息，因此需要注意被调用的频率，以避免影响到系统效率。 Because this incorrect design contains a large amount of data information, we need to pay attention to the frequency of calls to avoid affecting system efficiency.
使用例子 Example
package main
import "github.com/gwaylib/errors"
func fn1(a int) error {
if a == 1{
return errors.ErrNoData.As(a)
}
return errors.New("not implements").As(a)
}
func fn2(b int) error {
return errors.As(fn1(b))
}
func main() {
err := fn2(2)
if err != nil {
// errors.ErrNoData == err not necessarily true, so use Equal instead.
if !errors.ErrNoData.Equal(err) {
panic(err)
}
// Deals the same error.
fmt.Println(err)
}
}
Index ¶
Constants ¶
This section is empty.
Variables ¶
var (
ErrNoData = New("data not found")
)
Functions ¶
Types ¶
type Error ¶
type Error interface {
// Return the code of make.
Code() string
// Implement the error interface of go package
Error() string
// Impelment the json marshal interface of go package.
MarshalJSON() ([]byte, error)
// Record the stack when call, and return a new error with new stack.
As(arg ...interface{}) Error
// Compare to another error
// It should be established with err1.Code() == err2.Code().
Equal(err error) bool
}
func As ¶
Record the reason with as, and return a new error with new stack of reason. It would be safe for concurrency.
func ParseError ¶
Parse Error from a error instance. If the error is type of Error, it will be return directly.
Source Files