TAL Programmer's Guide

Modular Programming Example
Sample Programs
A–8 096254 Tandem Computers Incorporated
File-Naming Conventions This modular program follows these file-naming conventions:
Source file names end with the character S.
Object file names correspond to source file names and end with O. For instance,
the object file built from the source file INS is named INO.
Section names ending with D belong to a specific module. For instance, IND is the
section that contains LITERAL declarations for INS. Other section names are used
to provide a direct means for other source programs to copy individual procedures
when they need them. The section names beginning with END_OF_ are used
solely to mark the ends of actual sections.
File names ending with P each contains external declarations of the procedures in
the module with the corresponding identifier. A module that calls an external
procedure includes a SOURCE directive for the P file. For instance, the source for
MESSAGE_MODULE is file MSGS, and source file MSGP declares each external
procedure in MSGS. The modules that call MESSAGE_MODULE specify MSGP in
a SOURCE directive.
If any external declarations change, you must recompile both the P file and any
module that calls a changed external procedure. The P file enables compile-time
consistency checking between procedure declarations and the corresponding external
declarations.
A module also uses a P file for its external procedure declarations. Module xxxS uses a
SOURCE directive to specify xxxP, which contains external declarations for its
procedures. (Otherwise, the consistency check is possible only during a later binding.)