On 21/09/2020 17:13, Michael Morris wrote:
Next thing to consider - we have the problem of having already used the
protected keyword in PHP, and honestly I prefer PHP's interpretation of the
word.
I think it's actually Java that's the outlier here: PHP's meaning of
"protected" corresponds directly to C++, and to name a few I came upon
in a quick search it's also used that way by Kotlin [1], Scala [2], C#
[3] and Oxygene [4] - all of which use other ways to signal package
visibility:
- Kotlin has a fourth visibility, "internal", meaning "public within
this module"
- Scala has an interesting syntax where you can modify the visibility
with the name of a package, as in "private[SomePackage]"
- C# adds *three* extra visibility modes: "internal", "internal
protected", and "private protected"
- Oxygene (a language I know next to nothing about) apparently has no
fewer than TEN modes, including both "assembly or protected" and
"assembly and protected"
All of which I think shows two things: firstly, that there are lots of
different ways to express this concept; and secondly, that there are a
lot of subtle combinations that might be useful.
The C# list is particularly confusing, presumably because it's evolved
without a coherent plan. If I'm understanding correctly, C#'s "private
protected" corresponds to Oxygene's much clearer "assembly and
protected", while "protected internal" corresponds to "assembly or
protected". Considering those combinations up front might be sensible,
even if they're not implemented at once.
If we're considering using namespaces rather than a new package concept
for this, we potentially have a third dimension: is it private to _this
exact namespace_, or any "child" namespace starting with the same
prefix? Maybe something like Scala's modifier syntax might be more
useful, for instance:
namespace Acme\Frobulator\Helpers\File;
class FileWidget {
private[namespace] $foo; // accessible specifically in the
"Acme\Frobulator\Helpers\File" namespace
private[Acme\Frobulator\Helpers\File\*] $bar; // accessible in this
namespace, and all sub-namespaces
private[Acme\Frobulator\*] $baz; // accessible in "Acme\Frobulator"
and all its sub-namespaces
}
[1] https://kotlinlang.org/docs/reference/visibility-modifiers.html
[2] https://www.tutorialspoint.com/scala/scala_access_modifiers.htm
[3]
https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/access-modifiers
[4]
https://docs.elementscompiler.com/Oxygene/Members/VisibilityLevels/structs/access-modifiers
Regards,
--
Rowan Tommins (né Collins)
[IMSoP]
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