Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

document os

Browse source 
R=rsc
DELTA=143  (96 added, 0 deleted, 47 changed)
OCL=25876
CL=25888
This commit is contained in:
Rob Pike 2009-03-07 16:56:44 -08:00
parent 1910a7c595
commit 333cdd8f2a
6 changed files with 143 additions and 47 deletions
Download patch file Download diff file Expand all files Collapse all files

16
src/lib/os/error.go
View file

@ -6,8 +6,12 @@ package os
import syscall "syscall"
// Errors are singleton structures. Use the String() method to get their contents --
// it handles the nil (no error) case.
// Error is a structure wrapping a string describing an error.
// Errors are singleton structures, created by NewError, so their addresses can
// be compared to test for equality. A nil Error pointer means ``no error''.
// Use the String() method to get the contents; it handles the nil case.
// The Error type is intended for use by any package that wishes to define
// error strings.
type Error struct {
s string
}
@ -24,7 +28,8 @@ var errorStringTab = make(map[string] *Error);
// These functions contain a race if two goroutines add identical
// errors simultaneously but the consequences are unimportant.
// Allocate an Error object, but if it's been seen before, share that one.
// NewError allocates an Error object, but if s has been seen before,
// shares the Error associated with that message.
func NewError(s string) *Error {
if s == "" {
return nil
@ -38,7 +43,8 @@ func NewError(s string) *Error {
return err;
}
// Allocate an Error objecct, but if it's been seen before, share that one.
// ErrnoToError calls NewError to create an Error object for the string
// associated with Unix error code errno.
func ErrnoToError(errno int64) *Error {
if errno == 0 {
return nil
@ -53,6 +59,7 @@ func ErrnoToError(errno int64) *Error {
return err;
}
// Commonly known Unix errors.
var (
ENONE = ErrnoToError(syscall.ENONE);
EPERM = ErrnoToError(syscall.EPERM);
@ -92,6 +99,7 @@ var (
EAGAIN = ErrnoToError(syscall.EAGAIN);
)
// String returns the string associated with the Error.
func (e *Error) String() string {
if e == nil {
return "No Error"