如何建立重复的捕获组？

Question

I am trying to parse the following string:

`%%% First %%% part 1 %%% Second %%% part2`

This goes on and on into an unknown number of parts...e.g. Third, Fourth, Another, Car, Airplane, etc... all are separated by "%%% Something %%%"

I have:

package main

import (
    "fmt"
    "regexp"
)

func main() {
    reg:= regexp.MustCompile(`(?P<part>%%% .* %%%)+`)
    match := reg.FindStringSubmatch(`%%% First %%% part 1 %%% Second %%% part2`)
    if len(match) == 0 {
        fmt.Println("not found")
    }

    for i, g := range reg.SubexpNames() {
        if i == 0 || g == "" {
            continue
        }

        switch g {
        case "part":
            fmt.Println("part:", match[i])
        default:
            fmt.Printf("what group %q", g)
        }
    }

}

Gives:

part: %%% First %%% part 1 %%% Second %%%

How do I get output so that it prints like the following where part 1 and part 2 are separate matching groups? I would like to ignore "First" entirely and just focus on "Second":

part 2

https://play.golang.org/p/wLFwnk02dIJ

Answer 1

This makes the assumption that the pieces you are trying to capture follow the format of %%% Descriptor String %%% part where it will only print the part segment. This is expecting this pattern to repeat.

Also I added in the closing %%% that was missing from the given string.

With this pattern, it doesn't matter on having the closing %%%, but they don't harm either.

package main

import (
    "fmt"
    "regexp"
)

func main() {
    reg := regexp.MustCompile(`%%%[^%]*%%%(?P<part>[^%]*)`)
    match := reg.FindAllStringSubmatch(`%%% First %%% part 1 %%% Second %%% part2 %%% Third %%% wobble wobble %%%`, -1)
    if len(match) == 0 {
        fmt.Println("not found")
    }

    for i, _ := range match {
        fmt.Println("part:", match[i][1])
    }
}

This will print out:

part: part 1 part: part2 part: wobble wobble