fix(grainfmt): Fix grouping of expressions on LHS of fn application, record access etc

[marcusroberts]

Look for the special case of expressions on the left hand side of function application, record/array accessors and group with parens as appropriate.

Fixes #1559

[marcusroberts]

@ospencer does this look like it covers all the cases you can think of?

[ospencer]

I would probably reverse the logic and group everything that isn't one of the things to be grouped. Then you can just follow this: https://github.com/grain-lang/grain/blob/main/compiler/src/parsing/parser.mly#L545

So if it is not a:

• function call
• constant
• tuple
• identifier
• array access
• record access
• record
• block
• list
• array

Then it needs parens. That'll help us in the future too if we ever add more constructs; it's easier to tell what needs to be updated.

Maybe you might want to make a helper function for the above, so it's easy to modify if we update the parser rules.

[ospencer]

That'll also err on the side of being ugly but correct in the worst case.

[marcusroberts]

Thanks, that makes sense!

[marcusroberts]

Thanks @ospencer that's done I think.

[ospencer]

Overall looks great! Just some thoughts around naming.

[ospencer]

One small bug (related to the marshal format change)

[ospencer]

Looks great, excellent work @marcusroberts!

[phated]

Excellent!