match: ${if match{abcd}{^([ab]+)(\\w+)\$}{$2$1}fail}
match: ${if match{wxyz}{^([ab]+)(\\w+)\$}{$2$1}fail}
match: ${if match{abcd}{^([ab]+)(\\w+)\$}{$2[${if match{xyz}{(.*)}{$1}fail}]$1}fail}
match: ${if match{abcd}{^([ab]+)(\\w+)\$}{$2$1}fail}
match: ${if match{wxyz}{^([ab]+)(\\w+)\$}{$2$1}fail}
match: ${if match{abcd}{^([ab]+)(\\w+)\$}{$2[${if match{xyz}{(.*)}{$1}fail}]$1}fail}