英文:
Regular expression to capture a group that is optionally present in Go
问题
我正在尝试编写一个正则表达式，用于在表示Go代码的字符串中将类型名称（例如Bar）替换为更新后的名称（例如FooBar），但仅在它作为另一个结构体字段的类型或该类型的数组时才替换。因此，我想将以下代码：
type Foo struct {Bar BarBaz []BarBars []Bar}
转换为：
type Foo struct {Bar FooBarBaz []FooBarBars []FooBar}
到目前为止，我已经成功使用ReplaceAllString将数组字段类型进行了转换：
package mainimport ("fmt""regexp")func main() {re := regexp.MustCompile(`(\w+)(\s+)\[\]Bar`)s := `type Foo struct {Bar BarBaz []BarBars []Bar}`fmt.Println(re.ReplaceAllString(s, `$1$2[]FooBar`))}
这将产生以下输出：
type Foo struct {Bar BarBaz []FooBarBars []FooBar}
但是，缺少将Bar替换为FooBar的第一个字段的类型。我尝试将[]设为可选项，如下所示：
package mainimport ("fmt""regexp")func main() {re := regexp.MustCompile(`(\w+)(\s+)(\[\])?Bar`)s := `type Foo struct {Bar BarBaz []BarBars []Bar}`fmt.Println(re.ReplaceAllString(s, `$1$2$3FooBar`))}
但是，这会导致所有字段类型都丢失的输出：
type Foo struct {BarBazBars}
这里出了什么问题？（我可以使用两个不同的正则表达式进行两次处理，但我更希望一次完成）。
英文:
I'm trying to write a regular expression that in a string representing Go code will replace the name of a type, say Bar, with an updated name, say FooBar, but only where it appears as the type of a field in another struct or as an array of that type. So I'd like to convert for example
type Foo struct {Bar BarBaz []BarBars []Bar}
into
type Foo struct {Bar FooBarBaz []FooBarBars []FooBar}
So far, I've managed to convert the array field types using this ReplaceAllString:
package mainimport ("fmt""regexp")func main() {re := regexp.MustCompile(`(\w+)(\s+)\[\]Bar`)s := `type Foo struct {Bar BarBaz []BarBars []Bar}`fmt.Println(re.ReplaceAllString(s, `$1$2[]FooBar`))}
which produces
type Foo struct {Bar BarBaz []FooBarBars []FooBar}
The replacement of Bar is missing as the type of the first field, also named Bar. I've tried making the [] optional like so,
package mainimport ("fmt""regexp")func main() {re := regexp.MustCompile(`(\w+)(\s+)(\[\])?Bar`)s := `type Foo struct {Bar BarBaz []BarBars []Bar}`fmt.Println(re.ReplaceAllString(s, `$1$2$3FooBar`))}
But this produces an output where all of the field types are missing:
type Foo struct {BarBazBars}
What is wrong here? (I could use a two-pass approach with two different regular expressions, but I would prefer to achieve this in one go).
答案1
得分: 2
根据你的情况，gofmt可能是一个更好的选择：
gofmt -r 'Bar -> FooBar' hello.go
文件 hello.go
package hellotype Foo struct {FooBar FooBarBaz []FooBarBars []FooBar}
英文:
Depending on your situation, gofmt might be a better option:
gofmt -r 'Bar -> FooBar' hello.go
File hello.go
package hellotype Foo struct {FooBar FooBarBaz []FooBarBars []FooBar}
答案2
得分: 1
原文翻译如下：
原来第三个引用需要${3}，而不是$3：
package mainimport ("fmt""regexp")func main() {re := regexp.MustCompile(`(\w+)(\s+)(\[\])?Bar`)s := `type Foo struct {Bar BarBaz []BarBars []Bar}`fmt.Println(re.ReplaceAllString(s, `$1$2FooBar`))}
这将产生期望的结果
type Foo struct {Bar FooBarBaz []FooBarBars []FooBar}
英文:
It turns out the third reference needs to be ${3}, not $3:
package mainimport ("fmt""regexp")func main() {re := regexp.MustCompile(`(\w+)(\s+)(\[\])?Bar`)s := `type Foo struct {Bar BarBaz []BarBars []Bar}`fmt.Println(re.ReplaceAllString(s, `$1$2FooBar`))}
which produces the desired result
type Foo struct {Bar FooBarBaz []FooBarBars []FooBar}
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