🚀 go-pugleaf

Could someone say a few words about the typical 
applications of Collections, or indicate a reference that 
discusses them?  I am new to object-oriented programming 
and have not heard of collections as a construct before, 
and I do not have the appropriate TurboPascal manual.  Of 
course I can get an idea of the functionality from the 
routines, but I am still not sure what problems they are a 
solution for.

When I compiled Collections and the example program using 
Oberon/F 1.1 for the Mac and tried to run it, an error trap 
appeared because of the null value for file type in the 
example program when f.Register executes.  Here is a method 
of making this section of the example program 
platform-independent:

	CONST (* values supplied by Oberon microsystems *)
		Win32s	= 11;
		Windows95	= 12;
		WindowsNT	= 13;
		Cairo	= 14;
		MacOS7	= 21;
			
	VAR type : Files.Type;

..
		 IF Dialog.platform = MacOS7 THEN 
				type := "DATA";
		 ELSE
				type := "";
		 END;  (* IF *)
   f.Register("TEST.DAT", type, res);
..