英文:
Go regexp FindAllStringSubmatch
问题
这是我的Go代码片段，可以在这里找到：http://play.golang.org/p/L1AcgHf3E4。
package main
import (
"fmt"
"regexp"
)
func main() {
reg := regexp.MustCompile("([0-9]+[dh]){2}")
str := "2d3h5d"
fmt.Println(reg.FindAllStringSubmatch(str, -1))
}
我期望的结果是[[2d3h 3h] [3h5d 5d]]，但实际结果是[[2d3h 3h]]。你能解释一下为什么吗？提前谢谢。
英文:
here is my snippet of code in Go which can be found here http://play.golang.org/p/L1AcgHf3E4.
package main
import (
"fmt"
"regexp"
)
func main() {
reg := regexp.MustCompile("([0-9]+[dh]){2}")
str := "2d3h5d"
fmt.Println(reg.FindAllStringSubmatch(str, -1))
}
I'd expect the result to be [[2d3h 3h] [3h5d 5d]], but it turned out to be [[2d3h 3h]]. Can you explain why? Thanks in advance.
答案1
得分: 4
原因是你无法获得重叠的结果。对于支持前瞻的正则表达式引擎，你可以使用技巧：(?=([0-9]+[dh]){2})，但是Go语言不支持它。
如果你想获取所有的结果，我建议你使用FindAllStringIndex()和([0-9]+[dh])，然后确定所有连续的子字符串和偏移量。
英文:
the reason is that you can not obtain overlapping results. With regex engines that support lookahead you can use the trick: (?=([0-9]+[dh]){2}) but go language does not support it.
If you want to obtain all results, I suggest you to use FindAllStringIndex() with ([0-9]+[dh]) and then determine all contiguous substrings with the offset.
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