Re: [RFC] [Discussion] Clone with

On Thu, Apr 20, 2023 at 9:01 AM Rowan Tommins <rowan.collins@gmail.com> wrote: > > On 18 April 2023 17:48:00 BST, "Tim Düsterhus" <tim@bastelstu.be> wrote: > >I'd rather see only the fat-arrow being allowed. Unless I'm missing something, > >braces with colon is not used anywhere else, whereas braces + '=>' is known from > >match() and '=>' more generally is already used with array literals [1]. Having two > >similar syntaxes for the same thing is not great when both are commonly needed is not great. They > >need to be documented and learned by developers. > > > I think it makes sense to have an unquoted form here, because the common case is that they are > names which analysers can match statically to particular properties, not strings which will be > analysed at runtime. There are plenty of places in the language where dynamic names are allowed, but > we don't just use strings for the static case: > > ${'foo'} = 'bar'( constant('BAZ') )->{'quux'}(); > > > More specifically, the "name: $value" syntax matches named parameters, and while you > can use an array for that (via ... unpacking), we don't force users to do so. > > In fact, the Future Scope of that RFC considered the opposite: using the colon syntax in > arrays, along with a shorthand for pulling the key name from the variable name: > https://wiki.php.net/rfc/named_params#shorthand_syntax_for_matching_parameter_and_variable_name > > > If I wanted to put these ideas into a general framework, I think one way to go about this > > would be as follows: > > > > - Consider identifier: $expr as a shorthand for "identifier" => $expr.. > > - Consider :$variable as a shorthand for variable: $variable and thus > > "variable" => $variable. > > > That would give us: > > $point = ['x' => $x, 'y' => $y, 'z' => $z]; > $point = [x: $x, y: $y, z: $z]; > $point = [:$x, :$y, :$z]; > > $point = new Point(...['x' => $x, 'y' => $y, 'z' => > $z]); > $point = new Point(x: $x, y: $y, z: $z); > $point = new Point(:$x, :$y, :$z); > > $point = clone $point with {'x' => $x, 'y' => $y, 'z' => > $z}; > $point = clone $point with {x: $x, y: $y, z: $z}; > $point = clone $point with {:$x, :$y, :$z}; > > > > Rather than making everything use an array or array-like syntax, I would probably go the other > way and scrap the special syntax for dynamic names, making the whole thing look like a function > call, with support for array unpacking: > > $point = clone $point with (x: $x, y: $y, z: $z); > $point = clone $point with (...['x' => $x, 'y' => $y, 'z' > => $z]); > > > > Regards, > > -- > Rowan Tommins > [IMSoP] > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: https://www.php.net/unsub.php > I think using arrays here makes a lot of sense. For example, this example: public function withStatus($code, $reasonPhrase = ''): Response { return clone $this { $this->statusCode = $code; $this->reasonPhrase = "Old: $this->reasonPhrase, New: $reasonPhrase"; } }; could be rewritten with public function withStatus($statusCode, $reasonPhrase = ''): Response { // perform validation here $reasonPhrase = "Old: $this->reasonPhrase, New: $reasonPhrase"; return clone $this with compact('statusCode', 'reasonPhrase'); } I, personally, would find this much more ergonomic than writing out blocks of code and having a totally different syntax.