Named captures in Go

named_captures.go

package main

import (
	"fmt"
	"regexp"
)

func GetNamedMatches(exp *regexp.Regexp,
	src string, limit int) map[string][]interface{} {
	result := make(map[string][]interface{})
	matches := exp.FindAllStringSubmatch(src, limit)
	groups := exp.SubexpNames()
	for _, match := range matches {
		for pos, val := range match {
			fieldName := groups[pos]
			if fieldName == "" {
				continue
			}
			_, ok := result[fieldName]
			if !ok {
				result[fieldName] = make([]interface{}, 0)
			}
			result[fieldName] = append(result[fieldName], val)
		}
	}
	return result
}

func main() {
	exp := regexp.MustCompile("^/(?P<address>(?P<resource>\\w+)/(?P<id>[\\d]+))/(?P<action>[\\w]+)$")
	src := "/products/13/view"
	fmt.Printf("%+v\n", GetNamedMatches(exp, src, 2))
	format := "(?P<resource>/(?P<kind>\\w+)/(?P<id>\\d+))"
	exp2 := regexp.MustCompile(format)
	src2 := "/books/13/rentals/6"
	fmt.Printf("%+v\n", GetNamedMatches(exp2, src2, 2))
}