Variable-array parts

A variable-array phrase part describes a message part that is made up of a variable number of characters. Variable-arrays are restricted to the cases. By looking at each succeeding character in isolation, it can be determined if it belongs in the variable array. This property is reflected by the fact that component is a character set.

On input, the variable array matches as many successive characters in the component character set as possible.

  • component can be more than a single character. It can be a character constant, a named character set, or a composition of a character set using not or or.
  • If component is any, then this form has special meaning. Use this form inside a length-encoded region.

Except for length-encoded phrase parts, use variable-arrays to read a variable-length field up to some terminating character.

For example:

define phrase a-phrase;
field line = variable-array(not(<cr>));
<cr>;
<lf>;
end phrase;
Note: Do not use a variable-length field at the end of a phrase. The PDL would not know when to stop trying to read characters for the field.