模拟枚举类型

go语言中虽然没有Java, C++等一些高级语言提供的枚举类型特性，但可以使用常量和iota来模拟。 例如：

 1// BuildResult 构建结果
 2type BuildResult int
 3
 4const (
 5	// Success 成功
 6	Success BuildResult = iota
 7	// Fail 失败
 8	Fail
 9	// Abort 中断
10	Abort
11)

1var buildResult = Success
2println(buildResult) // 0

使用go generate和stringer生成String() string函数

https://godoc.org/golang.org/x/tools/cmd/stringergo generatefunc (t T) String() stringfmt.Stringer//go:generate stringer -type=BuildResult
 1// BuildResult 构建结果
 2//go:generate stringer -type=BuildResult
 3type BuildResult int
 4
 5const (
 6	// Success 成功
 7	Success BuildResult = iota
 8	// Fail 失败
 9	Fail
10	// Abort 中断
11	Abort
12)

go get -u golang.org/x/tools/cmd/stringer$GOPATH/bin$PATH
go generatebuildresult_string.go
 1// Code generated by "stringer -type=BuildResult"; DO NOT EDIT.
 2
 3package enums
 4
 5import "strconv"
 6
 7func _() {
 8	// An "invalid array index" compiler error signifies that the constant values have changed.
 9	// Re-run the stringer command to generate them again.
10	var x [1]struct{}
11	_ = x[Success-0]
12	_ = x[Fail-1]
13	_ = x[Abort-2]
14}
15
16const _BuildResult_name = "SuccessFailAbort"
17
18var _BuildResult_index = [...]uint8{0, 7, 11, 16}
19
20func (i BuildResult) String() string {
21	if i < 0 || i >= BuildResult(len(_BuildResult_index)-1) {
22		return "BuildResult(" + strconv.FormatInt(int64(i), 10) + ")"
23	}
24	return _BuildResult_name[_BuildResult_index[i]:_BuildResult_index[i+1]]
25}

使用生成的源码：

1var buildResult = Success
2println(buildResult.String()) // Success