[ https://issues.jboss.org/browse/DROOLS-1481?page=com.atlassian.jira.plugi... ] Edson Tirelli updated DROOLS-1481: ---------------------------------- Description: Function signatures as of now are only validated in runtime. We can improve it to add static validation as well. For instance, in the expression: {code}"$"+ (if Payment < 1000 then string(Payment) else (substring(string(Payment),1,1) + "," + substring(string(decimal(Payment,2),2)))){code} In runtime I get: {quote}Unable to find function 'string( class java.math.BigDecimal, class java.math.BigDecimal )'{quote} Because of: {code}...string(decimal(Payment,2),2)...{code} Instead of (see the misplaced parenthesis): {code}...string(decimal(Payment,2)),2...{code} I think we can also improve the error message to say: {quote}Unable to find function 'string( number, number )'{quote} was: Function signatures as of now are only validated in runtime. We can improve it to add static validation as well. For instance, in the expression: "$"+ (if Payment < 1000 then string(Payment) else (substring(string(Payment),1,1) + "," + substring(string(decimal(Payment,2),2)))) In runtime I get: Unable to find function 'string( class java.math.BigDecimal, class java.math.BigDecimal )' Because of: ...string(decimal(Payment,2),2)... Instead of (see the misplaced parenthesis): ...string(decimal(Payment,2)),2... I think we can also improve the error message to say: Unable to find function 'string( number, number )' -- This message was sent by Atlassian JIRA (v7.2.3#72005)