[jboss-jira] [JBoss JIRA] (DROOLS-1481) Validate function signature at compile time and improve error message

Validate function signature at compile time and improve error message --------------------------------------------------------------------- Key: DROOLS-1481 URL: https://issues.jboss.org/browse/DROOLS-1481 Project: Drools Issue Type: Feature Request Components: dmn engine Affects Versions: 7.0.0.Beta7 Reporter: Edson Tirelli Assignee: Matteo Mortari Priority: Major 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}