The JADE external function facility passes parameters using the following conventions.
Structured parameter (
Always passed by reference; that is, the address of the String or Binary variable is taken and passed
When usage is output or io (which signifies the calling function may update the value), length must be specified in the parameter definition
A function that returns a String primitive type is assumed to return a zero-terminated string
A function that returns a Binary primitive type must have the length of the Binary specified in the return type
Simple parameter (
When the usage is defined as constant or input, the parameter is passed by value
When the usage is defined as output or io, the parameter is passed by reference
Structured parameter (
Always passed by reference; that is, the address of the Point variable is taken and passed