◄Back►                                      ◄Up► ◄Contents► ◄Index► ◄Back►
────────────────────────────────────────────────────────────────────────────
 
     Dialects
 
     The syntax diagrams in the On-line Reference contain full syntax
     for all dialects. However, there is no indication of dialect on
     syntax diagrams.
 
     For full details of dialects and a full definition of the COBOL
     syntax please refer to your COBOL Language Reference.
 
     Railroad Tracks
 
     COBOL syntax is shown using diagrams called "railroad tracks", in
     which the words and phrases comprising a construct are shown
     joined by lines indicating the order they should be written in.
     You read these diagrams left-to-right. Each diagram starts with
     ►► and ends with ►◄.
 
     Sometimes the track forks to show alternatives and then joins up
     again. An arrow starting after a word or phrase and pointing back
     before it, forming a loop, means it can be repeated. The length
     of a track has no significance.
 
     When a diagram reaches the right-hand side of the screen, it is
     continued further down. A track continued onto a new line ends
     with ►, and the new line begins with ►. If several tracks are
     continued they are numbered so you can match up each track with
     its continuation.
 
     Within the diagrams, COBOL reserved words which are not significant
     and can be left out without affecting the sense of the statement
     (noise words) are indicated by a "drop-out" with narrow sides.
     Reserved words which are optional, but change the sense of the
     statement when included are shown by a drop-out with wide sides.
     For example, in the statement:
 
     ►►──GET─┬───┬─SYNTAX─┬───────────┬────►◄
             └NEW┘        └─BACKWARDS─┘
 
     the word NEW can be left out without affecting the operation.
     However, omitting the the word BACKWARDS will produce a different
     effect than if it is included.
 
 
     Multiple Formats
 
     Many COBOL statements have several alternative formats. When you
     enter the topic for such a statement, the format displayed under
     the "Syntax" heading is the one most commonly used. There is a
     format selector consisting of a button for each format; when you
     select a button, the format displayed changes to the one you
     have chosen. The button for the format currently displayed is
     highlighted.
 
     Within a format, all options are shown. There is no indication of
     which dialect each option belongs to. To distinguish dialects,
     see the ◄FLAG► directive.
                                    -♦-