HP 3000 Manuals HP 3000 Manuals
Overview
Language preprocessors exist in order to simplify source code. They
convert non-COBOL code within a COBOL program into standard COBOL
allowing the programmer to work more productively.
Such preprocessors are usually invoked as a separate operation from the
compiling phase of the development cycle (and are often known as
"pre-compilers"). This means not only an extra step in the development
cycle, but that any debugging tools which rely on the source code will
display the changed source code to the programmer - not the code as
written. This will again lengthen the development cycle.
The Integrated Preprocessor Interface does not have these disadvantages;
the preprocessing phase is so closely integrated with the compiling phase
that it becomes almost invisible.
This means that:
* listings contain only original source code
* Animator operates on the original source code
* errors identified by the preprocessor can cause a return to the
editor with a preprocessor-generated error message.
This chapter explains how to write an integrated preprocessor. You
should read it if you are creating a preprocessor for the first time or
if you are migrating a preprocessor from another environment.