in general, do not use a known Name value in PrintObj

[ThomasBreuer]

This addresses #5699.

For more than 25 years, there is a PrintObj method with high rank that just prints a known Name value of the object in question.
According to the documentation of Name, a known Name value should be used only by View and ViewObj; the function Print is recommended to show GAP input to reconstruct the object in question if this makes sense.

When we remove the PrintObj method in question, the tests from testinstall and teststandard show differences essentially in two situations:

• Certain global variables such as Rationals are currently expected to be printed via this name. The solution proposed here is to provide a PrintObj method with high rank that uses a known name under the condition that a global variable with this name exists.
• Some tests for groups returned by SimpleGroupsIterator call Print in order to show the names of these groups. Here we can call View instead of Print.

(Let us see the results of the other tests, perhaps there are more differences.)

[ThomasBreuer]

No, apparently the CI tests do not complain about the proposed change.
So is this a reasonable solution to Leonard's problem?

[Stefan-Kohl]

Would this really be a good idea? -- I mean, for example assume you name an object "X". Then, as I understand, with your proposal this would still be "Print"ed as "X", as there is a global variable named "X". (Or did I misread something?)

[ThomasBreuer]

@Stefan-Kohl

Would this really be a good idea? -- I mean, for example assume you name an object "X". Then, as I understand, with your proposal this would still be "Print"ed as "X", as there is a global variable named "X". (Or did I misread something?)

Well, this has been the behaviour since more than 25 years, and nobody has reported a problem with it.
Yes, one can set misleading names. If a user does this then it is his/her fault, and View will continue showing these names. (I think that function names such as X cause less confusion than names of objects such as Rationals.)

I think that Name should not be set by library functions, but this is another question to be answered.

[james-d-mitchell]

Looks good to me

[frankluebeck]

I do not support this new method. The way, an object is printed should not depend on the state of the GAP session in this way. (A global name can become bound and this may have no relation with the object to be printed.)

I would vote for removing this method completely.

Or, just leave it as it always was and adjust the documentation (if the additional work caused by removing it seems too much).

Also, I don't think that the proposed change addresses the issue #5699 appropriately. That should be done with better methods for viewing and printing those objects.

[fingolfin]

I think this should only be triggered if the variable with that name actually contains the object. I.e. like so:

Suggested change

	if ISBOUND_GLOBAL( Name( obj ) ) then
	Print( Name( obj ) );
	local name;
	name := Name( obj );
	if ISBOUND_GLOBAL( name ) and IS_IDENTICAL_OBJ( VALUE_GLOBAL( name ), obj ) then
	Print( name );