Avoid global state / global settings, esp. with common names

[fingolfin]

From read.g:

MIP_GLLIMIT := infinity;
COVER_LIMIT := 100;
POWER_LIMIT := 1000;

# some flags for the algorithm
if not IsBound(USE_PARTI) then USE_PARTI := false; fi;
if not IsBound(USE_CHARS) then USE_CHARS := false; fi;
if not IsBound(USE_MSERS) then USE_MSERS := false; fi;

# checking modes for the package
if not IsBound(CHECK_AUT) then CHECK_AUT := false; fi;
if not IsBound(CHECK_STB) then CHECK_STB := false; fi;
if not IsBound(CHECK_CNF) then CHECK_CNF := false; fi;
if not IsBound(CHECK_NQA) then CHECK_NQA := false; fi;

# store info
if not IsBound(STORE) then STORE := true; fi;
if not IsBound(COVER) then COVER := true; fi;
if not IsBound(ALLOW) then ALLOW := true; fi;

These are problematic because it means the results of computations can vary based on some invisible global state. It is e.g. conceivable that a user sets a variable like STORE for unrelated reasons, not knowing that this will affect modisom.

Possible solutions (which may be mixed as desired):

1. add a prefix identifying the package, such as MODISOM_, so that we have MODISOM_ALLOW
2. use the GAP package namespace feature; so e.g. ALLOW@ etc. -> this is turned internally by GAP into ALLOW@Modisom
3. some of them these settings could perhaps be turned into GAP options, so that the user can set them for specific function calls instead of globally

[limakzi]

@fingolfin Do you know, if this issue is still relevant?

[margollo]

Yes, this has not been resolved. It is rather tricky, as it involves many parts of the code.