mirror of
https://github.com/golang/go
synced 2024-11-12 09:50:21 -07:00
85 lines
1.6 KiB
Go
85 lines
1.6 KiB
Go
// $G $D/$F.go && $L $F.$A && ./$A.out
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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 main
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import "fmt"
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const (
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a = iota;
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b;
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c;
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d;
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e;
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)
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var x = []int{1,2,3}
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func f(x int, len *byte) {
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*len = byte(x);
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}
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func whatis(x interface{}) string {
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switch xx := x.(type) {
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default:
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return fmt.Sprint("default ", xx);
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case int, int8, int16, int32:
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return fmt.Sprint("signed ", xx);
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case int64:
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return fmt.Sprint("signed64 ", int64(xx));
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case uint, uint8, uint16, uint32:
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return fmt.Sprint("unsigned ", xx);
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case uint64:
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return fmt.Sprint("unsigned64 ", uint64(xx));
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case nil:
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return fmt.Sprint("nil ", xx);
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}
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panic("not reached");
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}
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func whatis1(x interface{}) string {
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xx := x;
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switch xx.(type) {
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default:
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return fmt.Sprint("default ", xx);
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case int, int8, int16, int32:
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return fmt.Sprint("signed ", xx);
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case int64:
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return fmt.Sprint("signed64 ", xx.(int64));
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case uint, uint8, uint16, uint32:
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return fmt.Sprint("unsigned ", xx);
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case uint64:
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return fmt.Sprint("unsigned64 ", xx.(uint64));
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case nil:
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return fmt.Sprint("nil ", xx);
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}
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panic("not reached");
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}
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func check(x interface{}, s string) {
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w := whatis(x);
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if w != s {
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fmt.Println("whatis", x, "=>", w, "!=", s);
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panic();
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}
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w = whatis1(x);
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if w != s {
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fmt.Println("whatis1", x, "=>", w, "!=", s);
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panic();
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}
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}
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func main() {
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check(1, "signed 1");
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check(uint(1), "unsigned 1");
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check(int64(1), "signed64 1");
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check(uint64(1), "unsigned64 1");
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check(1.5, "default 1.5");
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check(nil, "nil <nil>");
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}
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