Create a struct for VariableSpace

[mohdibntarek]

It would be nice to create a new struct VariableSpace and use that instead of Set for Sampler space. We can then overload Base.in to check if vn is inside space including the case when space is empty. We can overload in now with space::Set but that can cause confusion with the empty space case.

[phipsgabler]

In my VarName refactoring PR #49, the overloaded in(::VarName, ::Tuple) is replaced by a new function inspace. Does that make this issue obsolete?

[mohdibntarek]

Maybe but I still prefer VariableSpace and Base.in, less new function names. This is one thing we need to consider in DPPL and VarInfo. There are too many similar function names that can probably be simplified with structs and dispatch on Base functions that make sense.

[yebai]

Maybe but I still prefer VariableSpace and Base.in, less new function names. This is one thing we need to consider in DPPL and VarInfo. There are too many similar function names that can probably be simplified with structs and dispatch on Base functions that make sense.

Mohamed has some valid points here. We'd like to reduce the number of APIs in VarInfo if possible.

[devmotion]

I agree, having a VariableSpace struct might make sense due to the discrepancy of variable spaces to regular tuples caused by the empty spaces. But if we have a VariableSpace, one would probably have to add it to the API instead of inspace and one loses all existing functionality that is provided for free for tuples 🤷‍♂️

[yebai]

Seems this issue got fixed by #49?