Node: Source Structures, Next: Data Types, Up: Programming

### Source Structures

A source file accepted by GNU Pascal may contain up to one program, zero or more ISO-style modules, and/or zero or more UCSD-style units. Units and modules can be mixed in one project.

One trivial example for a valid GPC source file follows. Note that the code below may either be in one source file, or else the unit and the program may be in separate source files.

         unit DemoUnit;

         interface

         procedure Hello;

         implementation

         procedure Hello;
         begin
           WriteLn ('Hello, world!')
         end;

         end.

         program UnitDemo;

         uses
           DemoUnit;

         begin
           Hello
         end.