package builtin

type error interface {
    Error() string
}


######################
error接口定义

 

 

package errors

// 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) error {
    return &errorString{text}
}

// errorString is a trivial implementation of error.
type errorString struct {
    s string
}

func (e *errorString) Error() string {
    return e.s
}


######################################################
1.定义一个包含一个字符串的类errorString，并实现erro接口方法

2.创建一个errorString对象

 

package http


var (
    ErrBodyNotAllowed = errors.New("http: request method or response status code does not allow body")


    ErrHijacked = errors.New("http: connection has been hijacked")


    ErrContentLength = errors.New("http: wrote more than the declared Content-Length")


    ErrWriteAfterFlush = errors.New("unused")
)

########################################################################################################
erro使用：
直接使用errors包的New方法创建