Record Definition Language › RDL Repetition Groups

RDL Repetition Groups

If a sequence of 1 or more field definitions is repeated n times, it can be coded once with a repetition factor by enclosing the sequence in single quotes and preceding it with a 2-digit number, n, where 02<n<99. For example:

02'ZRF2,03'PDF4,C1F25''.

is an abbreviated form of

ZRF2,PDF4,C1F25,PDF4,C1F25,PDF4,C1F25,
ZRF2,PDF4,C1F25,PDF4,C1F25,PDF4,C1F25.

Repetition groups can be completely, but not partially, contained in conditional groups and conversely. Thus:

...(...03'...)...'  and   03'...(...'...)

are syntactical errors.

The symbol VS can be used instead of the 2-digit repetition factor to indicate that the value used is specified in a previous type V definition. VS is useful when the actual number of times that a field or a series of fields occurs within the record is variable and is contained in a separate field. For example, an invoice file consisting of variable-length records has a variably occurring series of 3 fields:

• Line item description, 20 bytes of character data
• Line item quantity, 4 bytes packed decimal data
• Line item amount, 7 bytes packed decimal data

A separate field in the record contains a value indicating the number of line items represented in the record. This field is 2 bytes in length and is zoned decimal format. The following is coded to define these fields:

...,VZ2,...,VS'C1F20,PDF4,PDF7' etc.

The characters enclosed in single quotes represent the line item fields.