mirror of
https://github.com/golang/go
synced 2024-11-22 00:44:39 -07:00
Remove exp/exception as it's no longer relevant
R=gri, adg CC=golang-dev, r, rsc https://golang.org/cl/857048
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@ -67,7 +67,6 @@ DIRS=\
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exp/datafmt\
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exp/draw\
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exp/eval\
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exp/exception\
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exp/iterable\
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expvar\
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flag\
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@ -1,11 +0,0 @@
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# Copyright 2009 The Go Authors. All rights reserved.
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# Use of this source code is governed by a BSD-style
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# license that can be found in the LICENSE file.
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include ../../../Make.$(GOARCH)
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TARG=exp/exception
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GOFILES=\
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exception.go\
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include ../../../Make.pkg
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@ -1,83 +0,0 @@
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// This package illustrates how basic try-catch exception handling
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// can be emulated using goroutines, channels, and closures.
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//
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// This package is *not* intended as a general exception handler
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// library.
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//
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package exception
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import (
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"fmt"
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"runtime"
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)
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// A Handler function handles an arbitrary exception value x.
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type Handler func(x interface{})
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// An Exception carries an exception value.
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type Exception struct {
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Value interface{} // Value may be the nil exception
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}
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// Try invokes a function f with a Handler to throw exceptions.
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// The function f may terminate abnormally with an arbitrary
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// exception x by calling throw(x) within f. If an exception is
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// thrown, Try returns an *Exception; otherwise it returns nil.
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//
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// Usage pattern:
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//
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// if x := exception.Try(func(throw exception.Handler) {
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// ...
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// throw(42); // terminate f by throwing exception 42
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// ...
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// }); x != nil {
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// // catch exception, e.g. print it
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// fmt.Println(x.Value);
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// }
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//
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// Alternative:
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//
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// exception.Try(func(throw exception.Handler) {
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// ...
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// throw(42); // terminate f by throwing exception 42
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// ...
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// }).Catch(func (x interface{}) {
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// // catch exception, e.g. print it
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// fmt.Println(x);
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// })
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//
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func Try(f func(throw Handler)) *Exception {
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h := make(chan *Exception)
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// execute try block
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go func() {
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f(func(x interface{}) {
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h <- &Exception{x}
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runtime.Goexit()
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})
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h <- nil // clean termination
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}()
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return <-h
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}
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// If x != nil, Catch invokes f with the exception value x.Value.
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// See Try for usage patterns.
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func (x *Exception) Catch(f Handler) {
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if x != nil {
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f(x.Value)
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}
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}
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func (x *Exception) String() string {
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if x != nil {
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return fmt.Sprintf("exception: %v", x.Value)
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}
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return ""
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}
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@ -1,61 +0,0 @@
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package exception
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import "testing"
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func TestNoException(t *testing.T) {
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e := Try(func(throw Handler) {})
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if e != nil {
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t.Fatalf("no exception expected, found: %v", e)
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}
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}
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func TestNilException(t *testing.T) {
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e := Try(func(throw Handler) { throw(nil) })
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if e == nil {
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t.Fatalf("exception expected", e)
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}
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if e.Value != nil {
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t.Fatalf("nil exception expected, found: %v", e)
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}
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}
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func TestTry(t *testing.T) {
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s := 0
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for i := 1; i <= 10; i++ {
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e := Try(func(throw Handler) {
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if i%3 == 0 {
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throw(i)
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panic("throw returned")
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}
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})
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if e != nil {
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s += e.Value.(int)
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}
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}
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result := 3 + 6 + 9
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if s != result {
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t.Fatalf("expected: %d, found: %d", result, s)
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}
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}
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func TestCatch(t *testing.T) {
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s := 0
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for i := 1; i <= 10; i++ {
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Try(func(throw Handler) {
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if i%3 == 0 {
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throw(i)
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}
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}).Catch(func(x interface{}) { s += x.(int) })
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}
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result := 3 + 6 + 9
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if s != result {
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t.Fatalf("expected: %d, found: %d", result, s)
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}
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}
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