Change `.t` to `.elem_type`

[Calvin-L]

The classes that represent collection types (TBag, TSet, and TList) use the attribute t for the type of their elements. This is ugly and is a bad name.

We should rename t to elem_type. This will be a wide-reaching change and we should be careful we got it right. Python's untyped nature makes it tricky.

Similarly, we might also want to perform these other renamings:

• ETupleGet.n --> .index
• EGetField.f --> .field_name
• SDecl.id --> .var (and change its type from str to EVar)
• SForEach.id --> .loop_var
• T and F --> ETRUE and EFALSE

(This is a follow-up to #43 and #44.)

[anhnamtran]

Do you just want this changed on TBag, TSet, and TList? There's also t in TApp, TRef, and TVector. Also TTuple has a ts and a n in it as well.

[Calvin-L]

Yes, those should probably also get cleaner names.

(Also, I am not sure TVector is used anymore.)

[anhnamtran]

I'll take a look at TVector and do some cleaning up.

[anhnamtran]

Similarly, are most of the .fs .fields as well? I was looking through it and it seems to make sense. Since they're in EArgMin and so on...

[Calvin-L]

No, most of the fs are functions. So perhaps:

• EArg{Min,Max}.f --> .key_function (reminiscent of key in Python's min, max, and sorted functions)
• ELet.f --> .body_function
• EMakeMap2.value --> .value_function

[anhnamtran]

When I change EArg(Min|Max).f to .key_function, EMap and EFlatMap breaks. For now I will temporarily change their .f to .key_function as well.

Followup: This is because in some places where you're checking isinstance(_, _) there are groups of EArg(Min|Max) or EFlatMap or EMap.

[Calvin-L]

Yep, those isinstance checks are hacky. They exploit the fact that all of those AST nodes have .e and .f properties. You should fix them by duplicating those checks and their bodies for each different case.

I agree that, too, feels wrong. We should think about a better design for the places that happens.

[anhnamtran]

Everything should be covered in #47.