Creating programs

Programs which are used to implement user-created functions consist of two separate parts:

1. The syntax specification
   In this part, the syntax of the parameters of the function is specified. The code is generated in the BIFDESC macro.

2. The execution specification
   This part contains the code for the function. A parameter list is passed from the system to the function, containing an array of n records (string_length, string_ptr, value_type); n is here equal to the number of parameters of the function plus two (function_value, returncode) (the number of function parameters may not exceed 254). The BIFMDL macro contains the records with their values and the data structures.