function Name

    [entry Parameter, ...]       :There may be several entry parameters.

     exit [@]Result            :

   return  [Expression]

A Function can have multiple Entry parameters or none. The last parameter is required and must be an Exit lising only one parameter. Functions can be called from an expression or by using the same calling format as a Method.

Value = Name( [Parameter, ...] );         Function syntax

NAME  [Parameter, ..., ]  Result;         Method call syntax

The name of a non-generic Function can potentially conflict with the name of an array or an Enumerated type. If that case the name will be interpreted as an array, then a function over the Enumeration. It's clearest if you can avoid using the same name between these enitities.

A Function is a pure procedure. That restricts them so they do not have side effects. Function procedure files can also contain Idiom procedures.

• They cannot perform input nor output, but Trace commands are allowed for debugging.


• They cannot raise Error exceptions, however Faults can always be raised anywhere in a program. A Precondition or any Assertion command within them can only raise a fault. They cannot contain Catch exception procedures.


• They only have read access to global variables and constants. Consequently they can include Use declarations, but not Alter declarations.


• Only Functions or pure Methods and Sequences can be called from within them.