Some functions that were already available in GAP 3 behave differently in GAP 4. This section lists them.
Orbit( G,pnt)
The GAP 3 manual promised that pnt would be the first entry of the resulting orbit. This was wrong already there in a few cases, therefore GAP 4 does not promise anything about the ordering of points in an orbit.
Order( g )
only takes the element g and computes its multiplicative order.
Calling Order with two arguments is permitted only in the
GAP 3 compatibility mode, see Compatibility Mode.
(Note that it does not make sense anymore to specify a group as
first argument w.r.t. which the order of the second argument shall
be computed, see Elements of Finitely Presented Groups.)
Position( list, obj )
If obj is not contained in the list list then fail is returned
in GAP 4 (see Fail), whereas false was returned in GAP 3.
Print( obj, ... )
Objects may appear on the screen in a different way,
depending on whether they are printed by the read eval print loop
or by an explicit call of Print.
The reason is that the read eval print loop calls the operation ViewObj
and not PrintObj, whereas Print calls PrintObj for each of its
arguments.
This permits the installation of methods for printing objects in a short form
in the read eval print loop while retaining Print to display
the object completely.
See also Section View and Print in the Reference Manual.
(PrintObj is installed as standard method ViewObj, so it is
not really necessary to have a ViewObj method for an object.)
PrintTo( filename, obj, ... )
In GAP 3, PrintTo could be (mis)used to ``redirect'' the text
printed by a function (that is, not only the output of a function)
to a file by entering the function call as second argument.
This was used mainly in order to avoid many calls of AppendTo.
In GAP 4, this feature has disappeared.
One can use streams (see Chapter Streams in the Reference Manual)
instead in order to write files efficiently.
[Top] [Previous] [Up] [Next] [Index]
GAP 4 manual