pkg: a slew of examples
R=golang-dev, gri, r
CC=golang-dev
https://golang.org/cl/5676071
diff --git a/src/pkg/errors/errors_test.go b/src/pkg/errors/errors_test.go
index c537eeb..63c05d7 100644
--- a/src/pkg/errors/errors_test.go
+++ b/src/pkg/errors/errors_test.go
@@ -5,29 +5,49 @@
package errors_test
import (
- . "errors"
+ "errors"
+ "fmt"
"testing"
)
func TestNewEqual(t *testing.T) {
// Different allocations should not be equal.
- if New("abc") == New("abc") {
+ if errors.New("abc") == errors.New("abc") {
t.Errorf(`New("abc") == New("abc")`)
}
- if New("abc") == New("xyz") {
+ if errors.New("abc") == errors.New("xyz") {
t.Errorf(`New("abc") == New("xyz")`)
}
// Same allocation should be equal to itself (not crash).
- err := New("jkl")
+ err := errors.New("jkl")
if err != err {
t.Errorf(`err != err`)
}
}
func TestErrorMethod(t *testing.T) {
- err := New("abc")
+ err := errors.New("abc")
if err.Error() != "abc" {
t.Errorf(`New("abc").Error() = %q, want %q`, err.Error(), "abc")
}
}
+
+func ExampleNew() {
+ err := errors.New("emit macho dwarf: elf header corrupted")
+ if err != nil {
+ fmt.Print(err)
+ }
+ // Output: emit macho dwarf: elf header corrupted
+}
+
+// The fmt package's Errorf function lets us use the package's formatting
+// features to create descriptive error messages.
+func ExampleNew_errorf() {
+ const name, id = "bimmler", 17
+ err := fmt.Errorf("user %q (id %d) not found", name, id)
+ if err != nil {
+ fmt.Print(err)
+ }
+ // Output: user "bimmler" (id 17) not found
+}
diff --git a/src/pkg/errors/example_test.go b/src/pkg/errors/example_test.go
new file mode 100644
index 0000000..0e86828
--- /dev/null
+++ b/src/pkg/errors/example_test.go
@@ -0,0 +1,34 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package errors_test
+
+import (
+ "fmt"
+ "time"
+)
+
+// MyError is an error implementation that includes a time and message.
+type MyError struct {
+ When time.Time
+ What string
+}
+
+func (e MyError) Error() string {
+ return fmt.Sprintf("%v: %v", e.When, e.What)
+}
+
+func oops() error {
+ return MyError{
+ time.Date(1989, 3, 15, 22, 30, 0, 0, time.UTC),
+ "the file system has gone away",
+ }
+}
+
+func Example() {
+ if err := oops(); err != nil {
+ fmt.Println(err)
+ }
+ // Output: 1989-03-15 22:30:00 +0000 UTC: the file system has gone away
+}
