Turbo Prolog

The project concept has two purposes:
I. The contents of the LIBRARIAN file are used during linkage; the names of the
modules are inserted into the link command (given via PLlNK.BAT) from that file.
2. The project name is used during compilation to identify a symbol table shared by
all modules in that project. The symbol table is stored in a file in the OBJ directory
with the same name as the project and file type .SYM . This file is automatically
generated and updated during compilation.
To achieve the second purpose, the name of the project must be given in each module
via the project compiler directive, which takes the form
project "MYPROJ"
Global Domains and Global Predicates
By default. all names used in a module are local. Turbo Prolog programs communicate
across module boundaries using predicates defined in a global predicates section.
The domains used in global predicates must be defined as global domains, or else be
domains of standard types.
All the modules in a project need to know exactly the same global predicates and
global domains. The easiest way to achieve this is by writing all -global declarations in
one single file, which can then be included in every relevant module via an include
directive.
global domains
A domain is made global by writing it in a global domains program section. In all other
respects, global domains are the same as ordinary (local) domains.
global predicates
global predicate declarations differ from ordinary (local) predicate declarations in that
they must contain a description of the flow pattern(s) in which each given predicate
may be called. A global predicates declaration must follow the scheme
mypred(dl,d2, .. ,dn) - (f,f, ... ,f)(f,f, .. ,f) ...
where d l,d2, ... ,dn are global domains and each group
(f, f, ... , f)
denotes a flow pattern where each (is either i (input parameter) or 0 (output parameter).
Note that if any global definition is changed, all modules in that project must be
recompiled.
Programmer's Guide 153