On 4/24/2016 1:00 PM, Zeev Suraski wrote: > > >> -----Original Message----- >> From: Sebastian Bergmann [mailto:sebast...@php.net] >> Sent: Sunday, April 24, 2016 12:14 PM >> To: internals@lists.php.net >> Subject: Re: [PHP-DEV] [RFC] PHP Attributes >> >> On 04/21/2016 11:13 PM, Dmitry Stogov wrote: >>> I would like to present an RFC proposing support for native annotation. >> >> Dmitry, >> >> please use "annotation" as the name for this feature and not "attribute". >> >> We already have attributes: it's what we use to store data in objects. And >> while some people call them "member variables" or "properties" the correct >> term for them (AFAIK) is "attribute". > > I don't think I've ever heard properties referred to as attributes in the > context of PHP. The PHP manual defines them and refers to them throughout as > 'properties'. > > (I'm not voicing an opinion on attributes vs. annotations; Just pointing out > that data storage inside objects isn't named attributes). > > Zeev >
The terminology here is pretty clear and you can just look it up, it has
nothing to do with PHP or Java or whatever. The main problem is simply
that people do not know the terminology and get mixed up. That is
usually okay in a casual discussion where each peer understands what the
other is referring to. However, we are dealing with language
specification here and need to be very exact or we fuck it up for the users.
`$x` is a property in the following example:
class A {
$x;
}
https://en.wikipedia.org/wiki/Property_%28programming%29
`private` is an attribute of property `$x` and an access modifier (not
visibility, because the property is still visible, e.g. via reflection,
and it only alters access to the property):
class A {
private $x;
}
https://en.wikipedia.org/wiki/Attribute_%28computing%29
Note that these things go further up in the terminology hierarchy to:
Field - https://en.wikipedia.org/wiki/Field_%28computer_science%29
Record - https://en.wikipedia.org/wiki/Record_%28computer_science%29
Data Structure - https://en.wikipedia.org/wiki/Data_structure
This is not the whole image yet, there are more things like (random order):
- functions
- methods
- members
- class variables
- static variables
- behavior
- data
- ...
You will notice, if you read all Wikipedia articles and related
documents, that these terms are too often used interchangeable. This is,
as mentioned before, mainly the case because people to not care about
terminology in general.
To sum it up, calling them attributes is outright wrong because not all
parts of a source code of a programming language has attributes. That is
why Sun chose the word annotation. Annotation means metadata that was
added to data. It does not say anything about the data itself and it
does not necessarily alter the data in any way, however, it can. This is
exactly what this feature is about. Since, an entity annotation does not
alter the data (in this case a class) itself but this additional
metadata may be used to configure other parts of the program.
The same is true for a method that has been annotated with test. The
data is not altered at all but is helps other parts of the program to
configure specific data and behavior based on this additional metadata
that was added to the data. Execution of the same method without those
other parts that react on the metadata does not do anything and the
program will execute normally.
TL;DR this feature *MUST* be called annotations (unless someone knows an
even better term) and the annotations *MAY* be used to add attributes to
properties but for many other things too.
--
Richard "Fleshgrinder" Fussenegger
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