Hello Joanna, seems you are quite new to programming, just kidding, so sad
you’ve missed the punch card era,
a lot of fun, but I cannot take you back there because my Delorean is broken :o)
Seriously, thank you for writing this, I share your opinion:
> In the light of the preceding paragraphs, I would, respectfully, suggest that
> "protected" should be allowed for exclusive use in the case of classes that
> really have to derive from each other, but for no other reason.
Exactly !
> Likewise, "private" should mean what it has meant and still means in most
> other languages, members of classes only, since, like "protected", that is
> its true nature.
Yes.
>
> What Swift presently calls "internal" seems to equate more to the C# concept
> of "internal" and, in my mind, needs no further discussion or change.
>
> Just as I was never happy with the Delphi concept of private and protected
> members being accessible, not just in the class or its derived types, but
> also from any code in the same code unit, I feel uneasy about the present
> definition of the private scope in Swift.
>
Me too.
> I have seen some horrendous abuses of that privileged access, with the
> gradual growth of single code units to truly gargantuan proportions, just
> because someone felt that certain classes needed to violate all the rules of
> common sense and be able to access each others' private parts (if you'll
> pardon the vernacular).
>
>
>
Especially this, couldn’t agree more:
> Personally, I would like to see the end of the file based scope and, instead,
> see more clearly defined "privileged" access between types, even if they are
> in the same code unit.
I would suggest the (true) use of “namespaces”, instead of file based scope,
so that entities *must* be imported or qualified by namespace.
When I started with Swift, i was under the false impression that Swift
concatenates all the sources in a project and simply treat this
as one single source file…
To my knowledge there is no way to hide class members. This is not good !
I’d like to show how i prefer it in this example:
“private” here means: only visible within the scope where it was declared!
Imho what private does now in Swift is
completely wrong.
“Protected” is here: like private but visible in descendants as well
namespace Eriador
{
class Mithril // This class is not visible outside the namespace.
{ // a + b
var a = 0.0 // should not visible outside this class/instance
private var b = 1.0 // “private”is the default
public var c = 1.0 // is visible outside the class
protected var d = “My precious…” // is also visible in descendants
init()
{
forgeRing()
}
// to use this function outside, it should be preceeded
// by a "public" keyword, like it is in Java:
public func stridingToMordor() -> Double
{
return a + b + c
}
}
} // end namespace Eriador
--------------------------------------------------------
//in another file
#import Foundation
namespace Rohan
{
#import namespace Eradior
func quest()
{
var mi = Mithril()
mi.a = 10.0 // Error: “a" and “b" are
mi.b = 10.0 // not public members of Aragorn
mi.c = 12345.67 // ok
print(ar.stridingToMordor()) // ok
}
}
Just my two cents to this ever lasting theme:
can’t see the wood for the trees anymore.
TedvG
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