问如何在javascript中从像twitter这样的字符串中提取@提及

EN

var str = "@jpotts18 what is up man? Are you hanging out with @kyle_clegg";
var pattern = /\B@[a-z0-9_-]+/gi;
str.match(pattern);
["@jpotts18", "@kyle_clegg"]

// Mention related regex collection
twttr.txt.regexen.validMentionPrecedingChars = /(?:^|[^a-zA-Z0-9_!#$%&*@＠]|RT:?)/;
twttr.txt.regexen.atSigns = /[@＠]/;
twttr.txt.regexen.validMentionOrList = regexSupplant(
    '(#{validMentionPrecedingChars})' +  // $1: Preceding character
    '(#{atSigns})' +                     // $2: At mark
    '([a-zA-Z0-9_]{1,20})' +             // $3: Screen name
    '(\/[a-zA-Z][a-zA-Z0-9_\-]{0,24})?'  // $4: List (optional)
  , 'g');
twttr.txt.regexen.endMentionMatch = regexSupplant(/^(?:#{atSigns}|[#{latinAccentChars}]|:\/\/)/);

var usernames = twttr.txt.extractMentions("Mentioning @twitter and @jack")
// usernames == ["twitter", "jack"]

var _ = require('underscore');

function parseMentions(text) {
    var mentionsRegex = new RegExp('@([a-zA-Z0-9\_\.]+)', 'gim');

    var matches = text.match(mentionsRegex);
    if (matches && matches.length) {
        matches = matches.map(function(match) {
            return match.slice(1);
        });
        return _.uniq(matches);
    } else {
        return [];
    }
}