On May 14, 2021, at 7:36 PM, Larry Garfield <la...@garfieldtech.com> wrote: > > On Fri, May 14, 2021, at 7:20 PM, Aaron Piotrowski wrote: >> >>> On May 14, 2021, at 7:00 PM, Larry Garfield <la...@garfieldtech.com> wrote: >>> >>> Is that actually going to come up? Given that PHP functions (at least >>> user-space ones) accept extra trailing arguments and just let them fall >>> off, I would *expect* a closure that way to do the same. Named arguments >>> continue that, I believe, by just ignoring any variadic arguments that do >>> not match a parameter in the function. It seems odd to go back on that >>> behavior now. >> >> I don't consider forwarding extra arguments an issue. I briefly was >> thinking it might be nice to be explicit about the number of arguments >> a partial would accept, but you convinced me otherwise in R11, so I >> think we're on the same page here. >> >>> >>> I can't speak for the others, but I could tolerate making "more than one >>> extra ? beyond the end of the parameter list is an error", potentially, as >>> at that point they're redundant. But if a function has, say, 4 params, >>> then fourParams(1, 3, ?) is a convenient way to say "and placeholder >>> everything else". Especially in dynamic cases like Nicolas pointed out, >>> you may not necessarily know how many arguments there are. >> >> With what I proposed in my last email, `fourParams(1, 3, ?)` is >> acceptable, there's nothing superfluous there. At least one ? is needed >> to declare a partial. Similarly, a partial for a no parameter function: >> `$partial = functionTakingNoParams(?)`. Or even a partial with args >> bound to all four params: `fourParams(1, 2, 3, 4, ?)`. >> >> What would error is `fourParams(1, 3, ?, ?)`, as the second ? is meaningless. >> >> I think you've convinced me that one-for-one matching on ? is >> burdensome, but the above is a happy medium perhaps? > > I'd be OK with "no more than one trailing ? in excess of what the underlying > callable has." (Which means if you don't know, just stick one ? at the end > and you know it will work.)
I think multiple trailing ? should be an error, otherwise how am I suppose to know at a glance if a partial declaration will error? Plus it’s adding multiple ways to declare the same thing, which I was hoping to avoid. fourParams(1, 2, ?); // OK fourParams(1, 2, ?, ?); // OK for you, should error to me fourParams(1, 2, ?, ?, ?); // Again OK for you, should error to me fourParams(1, 2, ?, ?, ?, ?); // Error for both What value is gained in allowing any of those but the first? I’d also be fine allowing a trailing ? in any declaration. It’s unnecessary, but one could argue that it’s consistent to allow a trailing ? in any partial, since it’s required for some. fourParams(?, 2, ?); // Could error, but probably fine for consistency Aaron Piotrowski
