Hi Rowan,

On Sat, June 6, 2020 at 7:06 AM Rowan Tommins <rowan.coll...@gmail.com> wrote:

> The `::` token in the parser is called `T_PAAMAYIM_NEKUDOTAYIM`, and 
> personally I find `T_SL` and `T_SR` just as cryptic and irrelevant. The most 
> common place I see those token names is when accidentally running code 
> with conflict markers like "<<<<<<<<", or when messing up heredoc 
> syntax; even if they weren't so abbreviated, my reaction would be "shift 
> what now?" I've used bit-shifts maybe twice in the last ten years, so 
> it's just not an immediate association to me.
>
> "Disingenuous" was probably too strong a word, but I do think it relates 
> to a fundamental difference in viewpoint: to some people, `<<` and `>>`
> are first and foremost the shift-left and shift-right operators, and so
> the immediate association on seeing them is so obvious it's not worth
> mentioning; to others, they just look like a new kind of brackets.
> 
> That association might actually be a good reason to avoid that syntax, 
> but if so it should be spelled out, rather than taken as a given.

That makes sense. I updated the RFC now to avoid usage of "shift tokens"
in most places and instead refer to them as `<<` and `>>` tokens. I also
added a sentence spelling out why the association with shift operators
may be confusing for some developers.

Additionally, the RFC more clearly lays out the issues with nested
attributes now.

> > Also, grouped attributes would probably have to be special-cased to
> > be disallowed in nested attributes, since they don't make sense there.
> 
> I'm not entirely clear how they work in current implementations like 
> Doctrine's, but I think nested attributes would have to have completely 
> different rules anyway, because you don't access them directly through 
> reflection in the same way.
> 
> If `<<Foo( <<Bar>> )>>` means something like `new Foo( new Bar )`, then I 
> can imagine it being useful for `<<Foo( <<Bar, Baz>> )>>` to mean
> `new Foo( [new Bar, new Baz] )`. That would actually be more convenient than
> the double-at version, where you'd have to write `@@Foo( [@@Bar, @@Baz] )`
> or use a constructor with a `...$variadic` parameter.

In that example there are the same number of characters either way, so
it's not clear the nested `<<>>` approach would be more convenient.
And do you think it's a good idea to have an additional syntax for
creating arrays like that? It seems like it could get confusing.

> Ultimately, it all comes down to judgement calls - is the 
> double-angle-bracket syntax "too verbose", "too ugly" when nested, etc; 
> and does the double-at syntax make it "better enough".

Yes, I agree that there's a judgment call to make. Out of curiosity,
given these shortcomings of the double-angle-bracket syntax, do you
think there are any objective reasons to prefer it over `@@` (other
than the theoretical BC break of code like `@@@really_suppress_me()`)?

Best regards,  
Theodore
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