rfc:class-like_primitive_types

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rfc:class-like_primitive_types [2016/12/19 21:56] ajfrfc:class-like_primitive_types [2017/09/22 13:28] (current) – external edit 127.0.0.1
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   * <php>$x instanceof array</php>   * <php>$x instanceof array</php>
   * <php>$x instanceof object</php>   * <php>$x instanceof object</php>
-  * <php>$x instanceof resource</php> (**FIXME:** should I omit this?)+  * <php>$x instanceof resource</php>
  
 ==== Features not extended to primitives ==== ==== Features not extended to primitives ====
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 In JavaScript, ''null'' does not have any properties or methods, but ''true'' and ''false'' do. In contrast, Python's ''None'' (its equivalent to null) //does// have properties and methods, albeit only magic methods. In JavaScript, ''null'' does not have any properties or methods, but ''true'' and ''false'' do. In contrast, Python's ''None'' (its equivalent to null) //does// have properties and methods, albeit only magic methods.
  
-This RFC currently chooses to omit null from support by most of these features.+This RFC currently chooses to omit null from the extension of most features of objects to the other types, but excepts <php>instanceof null</php> because it lacks the same potential to create errors.
  
-==== Should resource have a shadow class? ====+==== Should resource be supported? ====
  
 Resource is a legacy type that could be wholly replaced by objects in future. Extending these features to this type would be further entrenching it and contrary to the goal of its eventual removal. Resource is a legacy type that could be wholly replaced by objects in future. Extending these features to this type would be further entrenching it and contrary to the goal of its eventual removal.
 +
 +In particular, <php>instanceof resource</php> could create future backwards-compatibility problems if code uses it to check for values being resources and they later become objects.
  
 ===== Unaffected PHP Functionality ===== ===== Unaffected PHP Functionality =====
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 The extension of these features to the other primitive types opens up a number of future possibilities. The extension of these features to the other primitive types opens up a number of future possibilities.
  
-One of these would be [[http://nikic.github.io/2014/03/14/Methods-on-primitive-types-in-PHP.html|methods on the other primitive types]] (and also properties). This could make string and array manipulation more convenient, and additionally provides an opportunity for a fresh start versus the old standard string and array functions, which have notoriously inconsistent naming and parameter orders.+One of these would be [[http://nikic.github.io/2014/03/14/Methods-on-primitive-types-in-PHP.html|introducing new methods on the other primitive types]] (and also properties). This could lend string and array manipulation the convenience of method calls, and would provide an opportunity for a fresh start versus PHP's existing string and array functions, which have notoriously inconsistent naming and parameter orders
 + 
 +It also means we can easily introduce new superclasses of our other primitive types. For example, a new <php>\Number</php> type superclassing <php>int</php> and <php>float</php>, or a new <php>\Scalar</php> type superclassing everything except objects and arrays. Such superclasses could potentially be extended also by user-defined classes. 
 + 
 +Likewise, we could introduce new interfaces implemented by our other primitive types. One potential use for this is operator overloading. PHP could add an interface for number-like classes, which when implemented, would allow use of the number operators (''+ - * /'' etc.) with objects of that class. That interface could itself be implemented by PHP's own <php>int</php> and <php>float</php> types.
  
-It also means we can easily introduce new superclasses of our other primitive types. For example, a new <php>\Number</php> type superclassing <php>int</php> and <php>float</php>, or a new <php>\Scalar</php> type superclassing everything except objects and arrays.+<php>instanceof</php> could potentially support pseudo-types like <php>callable</php>.
  
 ===== Proposed Voting Choices ===== ===== Proposed Voting Choices =====
rfc/class-like_primitive_types.1482184597.txt.gz · Last modified: 2017/09/22 13:28 (external edit)