Simplify skipping syntax nodes...

[gafter]

in JuliaServices/AutoHashEqualsCached.jl#1 (comment) @nystrom wrote:

I'd make this more robust and just skip LineNumberNode, expecting a struct (or wrapped struct) at the beginning of the block. Or you could apply the macro to all structs in the block.

[NHDaly]

I think i agree with @nystrom. Or at least, you could consider asserting that there's only a single struct declaration in there. It seems it would a bit strange to encounter something like:

@auto_hash_equals begin
    struct Foo end
    struct Bar end
end

As a reader, i would probably incorrectly assume the macro is applying to all the structs, not just the first. No reason to keep this potential misunderstanding, i think.

[gafter]

The problem is that the block might be the result of applying a macro to the struct, and there might be a LineNumberNode in there when it is the result of applying the other macro. This is a scenario I'm trying to enable. So I think I do need to skip LineNumberNodes. However, your suggestion to assert a single struct or apply to every struct in the block if that situation arises - makes sense.

[gafter]

@NHDaly Asserting that there is only one struct would break this package's ability to interoperate with another hypothetical macro that produces a utility type during its expansion (inside begin ... end, which you get implicitly from quote). Is that what we intend?

[NHDaly]

hrmm yeah those are good points! Sorry for my long delay. 🤔 Yeah i don't have a great suggestion here then...

It's worth noting that i think macros run outside-in, so you should be able to see what the user wrote before any macros are expanded inside the usage?