Read lib/transatl.g before reading gap.ini

[wilfwilson]

I have made this PR as a result of what I think would be the best solution to #2828 and #2996.

Currently, lib/transatl.g is read in init.g a bit later than gap.ini. This means that if a package is autoloaded from gap.ini and the package uses a name declared in lib/transatl.g, then an unbound global variable warning is given. This happens with GRAPE 4.8.1 in particular.

This PR moves the reading of lib/transatl.g to the point directly before reading gap.ini.

Anyway, I've created this PR as a discussion point. There might be very good reasons for why this is a bad idea; in this case, I will be keen to hear about them!

[fingolfin]

Can you please edit the issue message to say Resolve #XYZ for all (both?) issues that would be resolved by merging this? Thank you!

[fingolfin]

To me this seems very sensible and plausible.

[fingolfin]

AFAICT, @hulpke originally wrote this code, so he might have additional insights. And perhaps some of the other people who've been around longer, such as @stevelinton @frankluebeck @ThomasBreuer ?

[wilfwilson]

@fingolfin Ah, sorry, I used Closes rather than Resolve – now I think about it, I suppose this closes the issue automatically without resolving it.

[wilfwilson]

Oh wait, no, there is no separate notion of closed or resolved. Is it okay how it is @fingolfin?

[olexandr-konovalov]

The consideration could be that e.g. before calling Transatlantic(IsPSolvable) one should have IsPSolvable declared already. Reading it earlier like in this PR does not break this. So it looks good for me then.

[hulpke]

Originally GAP had the convention that US spelling was used.

This bothered some users, who felt that if Stabiliser was good enough for her Majesty, it should be good enough for GAP. transatl.g simply does this renaming in bulk, rather than add a synonym in each declaration. As it only does so for library declared operations, it is fine to have it be used before reading in gap.ini.

The only reason I can see for loading it after gap.ini would be to enforce that packages should use the declared name and not synonyms. I can't see a good reason for doing so, and it would be a fight against windmills in any case.

[fingolfin]

@wilfwilson it is OK as it is -- I didn't see that you have the Closes lines in the commit messages, only looked at the PR description (where I usually put them, to make them more visible -- this is not a hidden request to change that here, BTW, just an explanation for my thought process :)

[ThomasBreuer]

I have no strong preferences about this topic, but since I have been asked:

• An argument for not reading transatl.g at all would be that due to the synonyms,
  tab completion stops before the end of the name even if the function is unique.

• An argument for reading transatl.g as late as possible would be
  that then it would be easier to find occurrences of function names with grep.

• The selection of function names for which transatlantic variants are available looks quite arbitrary.
  For example attribute testers and setters are not handled.
  The fact that this has not been observed indicates that the feature is used rarely.
  (The code would be able to deal with DeclareSynonymAttr, this is just not used.
  And of course one could simplify the code.)

[lhsoicher]

Thanks @wilfwilson. I agree with you. That said, I am happy to change any "Stabiliser" to "Stabilizer" for the next release of GRAPE.