HP 3000 Manuals HP 3000 Manuals
Chapter 19 Part V Dialect Summary Introduction to Dialect Summary
Micro Focus COBOL, which is implemented in this product, supports a
number of dialects of COBOL. It consists of a base of ANSI '74 COBOL,
which is always enabled, and the following optional dialects:
* ANSI '85 COBOL
* Data General Interactive COBOL
* Micro Focus extensions
* Microsoft V 1.1/IBM (PC) V 1.0 COBOL
* Microsoft V 2.2 COBOL
* IBM OS/VS COBOL
* Ryan MacFarland RM/COBOL V2
* IBM VS COBOL II
Notes: In addition, the Report Writer facility may be enabled.
IBMs SAA COBOL and the X/Open standard which are supported in
VS COBOL are not described explicitly in this document.
Both the ANSI '74 Standard and the ANSI '85 Standard allow implementors
to include extensions to the COBOL language and explicitly describe the
details of some features as implementor-defined. The resulting different
versions of COBOL, or dialects, mean that moving a program from one
compiler to another can involve a fair amount of work to amend it to the
new dialect.
To help overcome this problem, VS COBOL incorporates many of the most
widely used dialects of COBOL. The COBOL compiler cannot simply accept
all features of all these dialects unconditionally, because a word
available for use as a user-defined word in one dialect may be reserved
in another. So the compiler treats the dialects as alternatives; it
accepts dialect control directives, which reserve particular sets of
words needed for particular dialects. (See your COBOL System Reference
for a description of directives.)
Some dialect control directives can also be used as operands in the FLAG
directive. This makes the compiler flag any feature that is not in the
dialect that that directive controls. Flagging a feature means the
compiler allows it, but produces a message to draw the programmers
attention to it.
Generally, if a feature from some dialect does not need extra reserved
words, it is always accepted by the compiler. However, there are
instances where the same source code may produce different results in
different dialects. For these cases there are other language-affecting
directives you can use to control the behavior of specific features.
There are also a few directives to disable certain features that some
installations may not want to use.
The compiler treats COBOL as defined in the ANSI '74 Standard (excluding
the Report Writer module) as the base language. Whatever dialect control
directives are set, all features that appear in the ANSI '74 Standard
(excluding Report Writer) are accepted. For convenience, the ANSI '85
Standard and the Report Writer module of the ANSI '74 Standard are
treated as dialects.
The VS COBOL language has developed over the years, with features being
added at intervals, but always with compatibility with earlier versions
paramount. The different levels of COBOL functionality resulting from
this process are known as language levels. This reference also contains
useful information for users of products developed by Micro Focus as it
indicates in which product each feature first appeared.
The dialect control directives for some dialects can be followed by a
number; this clasifies as reserved words only the words needed for the
features implemented in a particular language level.
The tables in this reference list all features of VS COBOL that do not
appear in the ANSI 74 Standard. The features are divided according to
the dialect(s) in which they appear. These tables also list the language
level at which each feature was introduced as well as indicate directives
which enable particular behavior.