Modification

A group of objects can be given by specifying some editing to apply to another already existing group of objects. For instance, if the string new_*b|_ds|_im| was given in response to a request for a group expression, then the following steps occur:

• Each element in some existing group of objects (identified in the description of the parameter concerned) is substituted in turn for the ``*'' character.
• Any occurrences of the string ``_ds'' is replaced by the string ``_im''.
• The string ``b'' is added to the end of the string.
• The string ``new_'' is added to the start of the string.

Thus if the existing group contained the strings file1_ds and file2_ds, the resulting group would be new_file1_imb and new_file2_imb. Note, this facility is only available if the parameter description identifies an existing group which will be used as the basis for the modified strings.