Re: Strict switch statements

On Thu, Jun 14, 2018 at 4:35 AM, Nikita Popov <nikita.ppv@gmail.com> wrote: > I think if people want to use strict matching, they'll quite likely want to > have it on all cases. Something like "strict switch ($expr) {}" or "switch > strict ($expr) {}" or "switch (strict $expr) {}" or "switch ($expr) strict > {}" or "switch ($expr) { strict; }" or whatever would be preferable in that > case. > > Additionally, switch has the issue of fall-through behavior, which is > somewhat unexpected and error prone to many people. It might make sense to > introduce an entirely new "match" statement that conforms a bit more with > how switch-like strictures are implemented nowadays. That is, something like > > match ($expr) { >     "foo" => {...}, >     "bar" | "baz" => {...}, > } > > or similar. This might need some more design work to ensure forward > compatibility with potential future algebraic datatypes etc. I really like this idea. It's similar to the match control flow operator in Rust: https://doc.rust-lang.org/book/second-edition/ch06-02-match.html. One reason I almost never use the switch statement in PHP (besides the lack of strict matching) is that it's so verbose. Having to put a break keyword after every case to avoid fallthrough means that it almost always requires less code to use if statements instead. To avoid confusion with union types, I think I would prefer commas between or conditions instead of a pipe character. Example: ``` match ($expr) { "foo", "bar" => {echo 'expr is "foo" or "bar"';}, true => {echo 'expr is true';}, 1 => {echo 'expr is 1';}, null => {echo 'expr is null';}, false => {echo 'expr is false';}, default => {echo 'expr is something else';}, } ```