• "Kris" <fu bar.com> Jan 06 2006
• "John C" <johnch_atms hotmail.com> Jan 07 2006
• Chris Sauls <ibisbasenji gmail.com> Jan 07 2006
• Bruno Medeiros <daiphoenixNO SPAMlycos.com> Jan 09 2006
• Bruno Medeiros <daiphoenixNO SPAMlycos.com> Jan 09 2006
• "Walter Bright" <newshound digitalmars.com> Jan 09 2006
• "Kris" <fu bar.com> Jan 10 2006

"Kris" <fu bar.com> writes:

There seems to be some inconsistency in how method 'fields' are applied?

class A
{
        private bool quit;
        void halt() {quit = true;}
        bool isHalted() {return quit;}
}

void main()
{
        auto a = new A;

        a.halt;         // error here
        a.halt();

        a.isHalted;     // error here
        bool done = a.isHalted;
        if (a.isHalted)
           {
           }
}


compiling:

field.d(12): halt is not a field
field.d(15): isHalted is not a field

"John C" <johnch_atms hotmail.com> writes:

"Kris" <fu bar.com> wrote in message news:dpmt02$1ujf$1 digitaldaemon.com...
 There seems to be some inconsistency in how method 'fields' are applied?


I'm not sure there is such a thing in D. Maybe you mean 'properties'?

 class A
 {
        private bool quit;
        void halt() {quit = true;}
        bool isHalted() {return quit;}
 }

 void main()
 {
        auto a = new A;

        a.halt;         // error here


A.halt is neither a property nor a field, so must be called with 
parentheses, as below.

        a.halt();

        a.isHalted;     // error here


As above.

        bool done = a.isHalted;


This worked because A.isHalted meets the criterion of being a property.

class A {
    private bool quit;
    bool halt() { return quit = true; }
}

int main() {
    auto a = new A;
    bool halted = a.halt;
    return 0;
}

However, omit 'bool halted = ' and D won't treat 'A.halt' as a property, 
rather as a method.

        if (a.isHalted)
           {
           }
 }


 compiling:

 field.d(12): halt is not a field
 field.d(15): isHalted is not a field


Yet another reason to have a special notation for properties. 

Chris Sauls <ibisbasenji gmail.com> writes:

John C wrote:
 Yet another reason to have a special notation for properties. 


Main reason.  Properties need a special notation, specifically because as D
stands, it 
really doesn't have properties at all...  It has a property-like syntax sugar
that applies 
in select cases.  This is why I personally almost never use D's "properties" at
all, 
although I admittedly do use the specific pattern that D properties are written
in.  So 
/if/ they can be cleaned up to work in all cases, I guess I could be satisfied,
but I'd 
prefer a new notation.

-- Chris Sauls

Bruno Medeiros <daiphoenixNO SPAMlycos.com> writes:

John C wrote:
 "Kris" <fu bar.com> wrote in message news:dpmt02$1ujf$1 digitaldaemon.com...
 ...




This issue has nothing to do with properties.
It has to with the D feature that the 'value' (or better said, the 
evaluation result) of a function that has zero parameters is its 
function call, unlike in C where the value is the memory address.

somefunc  // in C it is &somefunc
somefunc  // in D it is somefunc()

And what we seem to have here is a bug (?) with this feature. Here's a 
simpler example, without classes involved:

   void func() { writefln("in func()"); }

   int main(char[][] args)
   {
	func;                      // does nothing
	func, "dummy_expression";  // calls func()
   }


-- 
Bruno Medeiros - CS/E student
"Certain aspects of D are a pathway to many abilities some consider to 
be... unnatural."

Bruno Medeiros <daiphoenixNO SPAMlycos.com> writes:

Bruno Medeiros wrote:
 
   void func() { writefln("in func()"); }
 
   int main(char[][] args)
   {
     func;                      // does nothing
     func, "dummy_expression";  // calls func()
   }
 



-- 
Bruno Medeiros - CS/E student
"Certain aspects of D are a pathway to many abilities some consider to 
be... unnatural."

"Walter Bright" <newshound digitalmars.com> writes:

"Kris" <fu bar.com> wrote in message news:dpmt02$1ujf$1 digitaldaemon.com...
 There seems to be some inconsistency in how method 'fields' are applied?


It's a bug, I'll fix it. 

"Kris" <fu bar.com> writes:

Thx;


"Walter Bright" <newshound digitalmars.com> wrote in message 
news:dpvnlf$1deb$1 digitaldaemon.com...
 "Kris" <fu bar.com> wrote in message 
 news:dpmt02$1ujf$1 digitaldaemon.com...
 There seems to be some inconsistency in how method 'fields' are applied?


 It's a bug, I'll fix it.