I have String in the following format

`blah blah [user:1] ho ho [user:2] he he he`

I want it to be replaced by

`blah blah <a href='1'>someFunctionCall(1)</a> ho ho <a href='2'>someFunctionCall(2)</a> he he he`

so two things replacement of [user:id] and a methodCall

note: I want to do it in groovy, what would be the efficient way of doing it