/**
 * 正则匹配替换
 * @param content 
 * @param pattern 
 * @param cb 
 * @returns 
 */
export function regexReplace(content: string, pattern: RegExp, cb: (match: RegExpExecArray) => string): string {
    if (content.length < 1) {
        return content;
    }
    const matches: RegExpExecArray[] = [];
    let match: RegExpExecArray|null;
    while (null !== (match = pattern.exec(content))) {
        matches.push(match as RegExpExecArray);
    }
    const block: string[] = [];
    for (let i = matches.length - 1; i >= 0; i--) {
        match = matches[i];
        block.push(content.substr(match.index + match[0].length));
        block.push(cb(match));
        content = content.substr(0, match.index);
    }
    return content + block.reverse().join('');
}