D - Property syntax
- Karl Bochert (20/20) May 18 2002 class Abc {
- Pavel Minayev (11/23) May 18 2002 No, because it doesn't allow for compile-time read-only (and write-only)
- Karl Bochert (11/41) May 18 2002 Surely it is better to have the read-only-ness expressed in the declarat...
- anderson (13/32) May 18 2002 Err, hm
- Jonathan Andrew (3/13) May 19 2002 So are all instance variables considered public by default then?
- anderson (6/19) May 19 2002 That'd be my guess to since much of the sample code at
- Erick JA (8/11) May 20 2002 Properties work fine for RAD aproach, make code more clear, an u can mak...
class Abc {
int myprop;
void property(int newproperty) { myprop = newproperty; } // set'er
int property() { return myprop; }// get'er
}
Isn't this syntax horribly redundant?
Doesn't
class Abc {
int <property> myprop;
}
carry just as much meaning? The compiler can generate default
gets and sets, and allow user-defined ones as well.
class Abc {
int <property> myprop;
void myprop ( Error ("Can't set myprop!") );
}
This provides clarity, saves a lot of typing, and (I would guess) is
easy to implement.
Karl Bochert
May 18 2002
"Karl Bochert" <kbochert ix.netcom.com> wrote in message news:1103_1021740941 bose...Doesn't class Abc { int <property> myprop; } carry just as much meaning? The compiler can generate default gets and sets, and allow user-defined ones as well.No, because it doesn't allow for compile-time read-only (and write-only) properties.class Abc { int <property> myprop; void myprop ( Error ("Can't set myprop!") ); } This provides clarity, saves a lot of typing, and (I would guess) is easy to implement.Clarity, maybe. But I don't care much of it, personally. As long as one groups property gettors and settors together, they are easy to spot. A lot of typing? Note, you had to define one function to define the property as read-only. Currently, you'd just define a single gettor. The same goes for write-only properties. And if it's read/write, you'll have to define 2 functions + 1 line which declares the property itself...
May 18 2002
Karl Bochert <kbochert ix.netcom.com> On Sat, 18 May 2002 21:07:22 +0400, "Pavel Minayev" <evilone omen.ru> wrote:"Karl Bochert" <kbochert ix.netcom.com> wrote in message news:1103_1021740941 bose...Surely it is better to have the read-only-ness expressed in the declaration than in the presence or absence of a specific function, somewhere in multiple pages of code!Doesn't class Abc { int <property> myprop; } carry just as much meaning? The compiler can generate default gets and sets, and allow user-defined ones as well.No, because it doesn't allow for compile-time read-only (and write-only) properties.Of course they also move more interesting code to the next page.class Abc { int <property> myprop; void myprop ( Error ("Can't set myprop!") ); } This provides clarity, saves a lot of typing, and (I would guess) is easy to implement.Clarity, maybe. But I don't care much of it, personally. As long as one groups property gettors and settors together, they are easy to spot.A lot of typing? Note, you had to define one function to define the property as read-only. Currently, you'd just define a single gettor. The same goes for write-only properties. And if it's read/write, you'll have to define 2 functions + 1 line which declares the property itself...I was looking at the example give in the manual, where a justification for the current syntax was that it reduced typing (from 111 characters to 99) as compared to C. This syntax reduces the example to 22, at no loss of clarity. Of course the issue is not typing, but the presence of 'typographic noise'. Karl
May 18 2002
Err, hm
Basically what http://www.digitalmars.com/d/class.html is saying is to use
class Abc
{
int property;
}
Until you need to cater for special cases then put the getters and setters
on, which is one word less then your <property> method.
PS -
It'd be nice though, if a resulting D IDE, could auto generate geter and
seter code (when it was needed) or even better support UML.
"Karl Bochert" <kbochert ix.netcom.com> wrote in message
news:1103_1021740941 bose...
class Abc {
int myprop;
void property(int newproperty) { myprop = newproperty; } // set'er
int property() { return myprop; }// get'er
}
Isn't this syntax horribly redundant?
Doesn't
class Abc {
int <property> myprop;
}
carry just as much meaning? The compiler can generate default
gets and sets, and allow user-defined ones as well.
class Abc {
int <property> myprop;
void myprop ( Error ("Can't set myprop!") );
}
This provides clarity, saves a lot of typing, and (I would guess) is
easy to implement.
Karl Bochert
May 18 2002
So are all instance variables considered public by default then?
-Jon
anderson wrote:
Err, hm
Basically what http://www.digitalmars.com/d/class.html is saying is to use
class Abc
{
int property;
}
May 19 2002
That'd be my guess to since much of the sample code at http://www.digitalmars.com is represented that way. After I had added my get and set functions I'd move the variable into protected or private space. "Jonathan Andrew" <jon ece.arizona.edu> wrote in message news:3CE7E24B.5040209 ece.arizona.edu...So are all instance variables considered public by default then? -Jon anderson wrote:useErr, hm Basically what http://www.digitalmars.com/d/class.html is saying is toclass Abc { int property; }
May 19 2002
In article <ac7h7t$8il$1 digitaldaemon.com>, anderson says...Err, hm Basically what http://www.digitalmars.com/d/class.html is saying is to useProperties work fine for RAD aproach, make code more clear, an u can make properties read,read/write, public, private...and more. To day language not is only a compiler is more than that, we need tools (builder, RADs, and more). One example, if you wan't make Enterprice JavaBeans you nead emulate properties in the program, in the IDE or Builder and in the interface, so are to bad properties?.....
May 20 2002