Include file:
One of these is used by the editor to save and restore drawing editor
documents in idraw "PostScript" format or in an ASCII variable-length
record format (each record enclosed in parenthesis separated by commas,
with nesting for hierarchical objects). Reading in "PostScript" is done
with the balance of "Read" methods below. Reading in the ASCII script
files is done with the istream constructors of classes derived from OverlayComp.
Only writing in script is supported by this class. Writing in idraw "PostScript"
is handled by IdrawCatalog.