Using operators in API body

[M-Hagras]

I am trying to loop over source[List] to get data attribute pushing it to source.

I am using for loop but I get an error in codition operator. how can I escape it?
code
.body("for(int i=0 ; i<=${source}.size() ; i++) ${destination}.add(${source}.get(0).getXValue());" + "return ${destination};"))
Error

unexpected character in markup = (position: START_TAG seen ... to ="getXValue" type ="DYNAMIC">for(int i=0 ; i<=... @220:123)