voicera/gooseberry

// Package regex provides regular expressions utilities.
package regex

import (
    "regexp"
)

// FindNamedStringSubmatch returns a map whose elements are the names of
// explicitly named capturing groups in the specified pattern (denoted by
// ?P<name>) and their respective submatches in the input string, as
// defined by the 'Submatch' description in the regexp package comment.
// A return value of nil indicates no match (to be consistent with regexp).
// A return value of an empty map indicates lack of any named capturing group.
func FindNamedStringSubmatch(pattern *regexp.Regexp, input string) map[string]string {
    matches := pattern.FindStringSubmatch(input)
    if matches == nil {
        return nil
    }

    names := pattern.SubexpNames()
    mapping := make(map[string]string, len(names))
    for i, key := range names {
        if key != "" {
            mapping[key] = matches[i]
        }
    }

    return mapping
}