rfc:callable-types

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rfc:callable-types [2016/04/26 17:26] – amendments regarding references, optional types, fix error messages nikita2206rfc:callable-types [2016/06/06 21:25] – nikita2206
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-====== PHP RFC: Callable Types ======+====== PHP RFC: Callable Prototypes ======
   * Version: 1.0   * Version: 1.0
   * Date: 2015-08-27   * Date: 2015-08-27
   * Authors: Nikita Nefedov <inefedor@gmail.com>, Márcio Almada <marcio3w@gmail.com>   * Authors: Nikita Nefedov <inefedor@gmail.com>, Márcio Almada <marcio3w@gmail.com>
-  * Status: Under Discussion+  * Status: Declined
   * First Published at: http://wiki.php.net/rfc/callable-types   * First Published at: http://wiki.php.net/rfc/callable-types
  
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 </code> </code>
  
-Optional parameters count just like any other arguments if they are typed:+Optional parameters count just like any other parameters if they are typed:
 <code php> <code php>
 function foo(callable() $cb) { } function foo(callable() $cb) { }
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 There's no way to declare that you expect a callable that returns reference due to syntax limitations. There's no way to declare that you expect a callable that returns reference due to syntax limitations.
 +
 +==== Parameters with default values ====
 +
 +It's not possible to declare default value of a parameter in a callable prototype. Because currently PHP doesn't consider parameter's default values in signature validation (their invariance is not enforced in overridden methods in classes).
  
 ==== Syntax Choices ==== ==== Syntax Choices ====
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 function foo(callable($a, $b):void $callback) { function foo(callable($a, $b):void $callback) {
   //...   //...
 +}
 +</code>
 +
 +===== Reflection =====
 +
 +There are no BC-breaking changes in Reflection.
 +
 +Here are the changes needed for reflection:
 +
 +`ReflectionParameter::getType()` can now return instance of `ReflectionCallableType` which extends `ReflectionType`:
 +
 +<code php>
 +class ReflectionCallableType extends ReflectionType
 +{
 +    /**
 +     * Tells whether it's just a `callable` hint or if it has a prototype `callable(something): something`
 +     */
 +    public function hasPrototype(): bool;
 +
 +    /**
 +     * Returns a number of parameters required by a callable prototype
 +     */
 +    public function getArity(): bool;
 +
 +    /**
 +     * Returns an array of ReflectionCallableParameter instances
 +     */
 +    public function getParameters(): array;
 +
 +    /**
 +     * Tells whether the prototype has return type defined
 +     */
 +    public function hasReturnType(): bool;
 +
 +    /**
 +     * Returns return type of the callable prototype
 +     */
 +    public function getReturnType(): ReflectionType;
 +
 +    /**
 +     * Tells whether $value has compatible callable prototype. This is the easiest way
 +     * to implement runtime-error-free compatibility checks at this point...
 +     * Later we could implement it in the form of `instanceof`
 +     */
 +    public function isA($value);
 +}
 +
 +class ReflectionCallableParameter
 +{
 +    /**
 +     * Tells whether this callable parameter has a type
 +     */
 +    public function hasType(): bool;
 +
 +    /**
 +     * Returns a type of this callable parameter
 +     */
 +    public function getType(): ReflectionType;
 +
 +    /**
 +     * Tells whether callable parameter is named or not (e.g. callable(Foo $foo) vs callable(Foo))
 +     */
 +    public function hasName(): bool;
 +
 +    /**
 +     * Returns name of the callable parameter
 +     */
 +    public function getName(): string;
 +
 +    /**
 +     * Whether this is by-val or by-ref parameter
 +     */
 +    public function isPassedByReference(): bool;
 +    
 +    /**
 +     * Whether this is a variadic parameter
 +     */
 +    public function isVariadic(): bool;
 } }
 </code> </code>
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 while PHP lacks first class packages. while PHP lacks first class packages.
  
-==== Reflection API ====+===== Votes =====
  
-An extension to the reflection API will be proposed in case the RFC is approved. +This RFC requires a 2/3 majority to pass. Vote started on May 23, 2016, ends June 6, 2016.
- +
-===== Votes =====+
  
-This RFC requires a 2/3 majority to pass.+<doodle title="Accept callable prototypes?" auth="nikita2206" voteType="single" closed="true"> 
 +   * Yes 
 +   * No 
 +</doodle>
  
 ===== Patches and Tests ===== ===== Patches and Tests =====
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     - Scala     - Scala
     - Swift https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Types.html     - Swift https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Types.html
- 
rfc/callable-types.txt · Last modified: 2017/09/22 13:28 by 127.0.0.1

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