Compiling User-Defined Function Definitions

The characteristics of a user-defined function are extracted to internal data areas whenever the Compiler encounters a user-defined function definition, The data extracted is analogous to an implicit prototype, with characteristics such as the function name, returning item data description, and parameter item data description extracted.

If a function is invoked in a subsequent compilation unit, that has the same function name, a conformance check is carried out, where the Compiler determines if the provided invocation context, arguments, and returning item are appropriate.