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digitalmars.D - Some operators in D...

reply Sam <Sam_member pathlink.com> writes:
Hey, what's with this:

if(a === null)

Then does that mean I can do this:

if(a !=== null)

??? I'm sorry, this operator syntax looks stupid!  Honestly!  Why not create an
operator 'is':

if(a is null)

Just like in SQL!

Or better yet, why not create a built-in operator, function or property on ALL
classes that derive from Object called 'isnull'?  If you do that, you can get
rid of the 'null' keyword as it would become obsolete.

if(a.isnull)
if(!a.isnull)

I'm sorry, I don't like '==='.  This is going too far!!

I also don't like '<<<', and I have seen '<<<=' and '>>>=' in javascript.  NOT
PRETTY!!
:(

Sam-
sam987883 yahoo.com
May 25 2005
next sibling parent Derek Parnell <derek psych.ward> writes:
On Wed, 25 May 2005 23:08:34 +0000 (UTC), Sam wrote:


 Hey, what's with this:
 
 if(a === null)
 
 Then does that mean I can do this:
 
 if(a !=== null)
 
 ??? I'm sorry, this operator syntax looks stupid!  Honestly!  Why not create an
 operator 'is':
 
 if(a is null)
 
 Just like in SQL!


Keep reading the specs. There is an 'is' operator which is an alias for
"===". The triple '=' operator is being phased out so I wouldn't use it any
more. The "!==" operator is the negative of "is" but moves are afoot to
have that replaced by a better operator too.


 Or better yet, why not create a built-in operator, function or property on ALL
 classes that derive from Object called 'isnull'?  If you do that, you can get
 rid of the 'null' keyword as it would become obsolete.
 
 if(a.isnull)
 if(!a.isnull)
 
 I'm sorry, I don't like '==='.  This is going too far!!


You are not alone, and it was superseded. We are trying hard to get "!=="
replaced too.

-- 
Derek
Melbourne, Australia
26/05/2005 9:10:09 AM
May 25 2005
prev sibling next sibling parent Brad Beveridge <brad somewhere.net> writes:
Sam wrote:

 Hey, what's with this:
 
 if(a === null)
 
 Then does that mean I can do this:
 
 if(a !=== null)


That would be !==


 
 ??? I'm sorry, this operator syntax looks stupid!  Honestly!  Why not create an
 operator 'is':
 
 if(a is null)


D now has the "is" operator, with "!is" on the way. "===" and "!==" are 
looking like they'll get deprecated.


 I also don't like '<<<', and I have seen '<<<=' and '>>>=' in javascript.  NOT


There is no "<<<" expression, and ">>>", unsigned shift right, is a 
potentially useful operator in places.  Though I doubt you'll see it 
often considering how rare << and >> are already.

Brad
May 25 2005
prev sibling parent reply =?UTF-8?B?QW5kZXJzIEYgQmrDtnJrbHVuZA==?= <afb algonet.se> writes:
Sam wrote:


 Hey, what's with this:
 
 if(a === null)
 
 Then does that mean I can do this:
 
 if(a !=== null)


Yes. For now, at least... It's called '!==', though ?
(compare with '==' and '!=' for equality expressions)

Some people (like myself) think that's a *good* thing...
(I happened to like the === [≡] and !== [≢], too bad)


 ??? I'm sorry, this operator syntax looks stupid!  Honestly!  Why not create an
 operator 'is':
 
 if(a is null)
 
 Just like in SQL!


Must be your lucky day then. Your wish has been granted,
Walter has now deprecated the '===' identity expressions...

"if (a is null)" is legal D code, since DMD 0.76 (Nov 2003).
The naming jury is still out on the "not" version of 'is'.


 Or better yet, why not create a built-in operator, function or property on ALL
 classes that derive from Object called 'isnull'?  If you do that, you can get
 rid of the 'null' keyword as it would become obsolete.
 
 if(a.isnull)
 if(!a.isnull)


But you would still need 'null' for pointers ?

And currently D uses:
if (a)
if (!a)

But that might change too, some future day...

--anders
May 26 2005
parent reply Sam <Sam_member pathlink.com> writes:
 Or better yet, why not create a built-in operator, function or property on ALL
 classes that derive from Object called 'isnull'?  If you do that, you can get
 rid of the 'null' keyword as it would become obsolete.
 
 if(a.isnull)
 if(!a.isnull)


But you would still need 'null' for pointers ?


a.makenull();

How about this???  I still believe the 'null' keyword can be deprecated!  :-O

Sam-
sam987883 yahoo.com
May 26 2005
next sibling parent reply "Unknown W. Brackets" <unknown simplemachines.org> writes:


I really don't see why having null is a problem.  And I would never 
support anything that would make this:

Class a;
if (a.isnull)

Legal, but this:

Class a;
if (a.prop)

A segfault.  Yuck, talk about confusing for newbies.

-[Unknown]



Or better yet, why not create a built-in operator, function or property on ALL
classes that derive from Object called 'isnull'?  If you do that, you can get
rid of the 'null' keyword as it would become obsolete.

if(a.isnull)
if(!a.isnull)


But you would still need 'null' for pointers ?


 
 
 a.makenull();
 
 How about this???  I still believe the 'null' keyword can be deprecated!  :-O
 
 Sam-
 sam987883 yahoo.com
May 26 2005
parent reply Sam <Sam_member pathlink.com> writes:
You're right!!  What was I smoking!!  Sorry!

What I meant was some static methods:

class a {}

if(!Object::isnull(a))
Object::makenull(a);

How about these?  They don't have to be under class Object:

if(D::isnull(a))
D::nullify(a);

D-licious!!

In article <d74rpa$2miv$1 digitaldaemon.com>, Unknown W. Brackets says...



I really don't see why having null is a problem.  And I would never 
support anything that would make this:

Class a;
if (a.isnull)

Legal, but this:

Class a;
if (a.prop)

A segfault.  Yuck, talk about confusing for newbies.

-[Unknown]



Or better yet, why not create a built-in operator, function or property on ALL
classes that derive from Object called 'isnull'?  If you do that, you can get
rid of the 'null' keyword as it would become obsolete.

if(a.isnull)
if(!a.isnull)


But you would still need 'null' for pointers ?


 
 
 a.makenull();
 
 How about this???  I still believe the 'null' keyword can be deprecated!  :-O
 
 Sam-
 sam987883 yahoo.com
May 26 2005
parent reply "Unknown W. Brackets" <unknown simplemachines.org> writes:
Well, it would be:

if (!Object.isnull(a))
    ...
else
    Object.nullify(a);

But, still, that's longer than:

if (a is null)
    ...
else
    a = null;

And also less clear.  I don't think it is D's purpose to kill or hide 
pointers, either, and null is useful with pointers as well (essentially 
the same as 0, but much more clear.)

What I'm having trouble understanding is really what problem this is 
meant to address; just that you don't like ===, is, and null?

-[Unknown]



 You're right!!  What was I smoking!!  Sorry!
 
 What I meant was some static methods:
 
 class a {}
 
 if(!Object::isnull(a))
 Object::makenull(a);
 
 How about these?  They don't have to be under class Object:
 
 if(D::isnull(a))
 D::nullify(a);
 
 D-licious!!
May 26 2005
parent reply Sam <Sam_member pathlink.com> writes:
Ok then why not put 'isnull' and 'nullify' into a namespace or make them
built-in?

Then:

if(isnull(a))
..
else
nullify(a);

Granted it's not as small as the syntax with 'is' and 'null', but this
eliminates the need for 'is' and 'null'.
You see, to me my way is simpler:

if(isnull(a)) // 1 isnull method, 1 argument
if(a is null) // 1 is operator, 2 arguments (1 special keyword)

nullify(a) // 1 method, 1 argument
a = null   // 1 operator, 2 arguments (1 special keyword)

if(!isnull(a)) // 1 ! operator, 1 isnull method, 1 argument
if(a !== null) // 1 !== operator, 2 arguments (1 special keyword)


I am for a 'not' keyword though!!  It's better than this '!' that carried over
from c++!

Recap of what I propose:

Get rid of: 'null', 'true', 'false', '!', '!==', 'is'
Add:        'not', 'isnull', 'nullify', 'truthify', 'falsify'

;-D

In article <d7502f$2q6o$1 digitaldaemon.com>, Unknown W. Brackets says...

Well, it would be:

if (!Object.isnull(a))
    ...
else
    Object.nullify(a);

But, still, that's longer than:

if (a is null)
    ...
else
    a = null;

And also less clear.  I don't think it is D's purpose to kill or hide 
pointers, either, and null is useful with pointers as well (essentially 
the same as 0, but much more clear.)

What I'm having trouble understanding is really what problem this is 
meant to address; just that you don't like ===, is, and null?

-[Unknown]
May 26 2005
next sibling parent reply Brad Beveridge <brad somewhere.net> writes:
 Recap of what I propose:
 
 Get rid of: 'null', 'true', 'false', '!', '!==', 'is'
 Add:        'not', 'isnull', 'nullify', 'truthify', 'falsify'
 


Sorry, doesn't get my vote (not that this is a democracy :) - I don't 
like that syntax at all.

Brad
May 26 2005
parent Sam <Sam_member pathlink.com> writes:
THAT'S IT!!  I have it with all of these keywords!!!!
I'm coming up with MY OWN language called:

E()


In article <d754a6$2tpu$1 digitaldaemon.com>, Brad Beveridge says...

 Recap of what I propose:
 
 Get rid of: 'null', 'true', 'false', '!', '!==', 'is'
 Add:        'not', 'isnull', 'nullify', 'truthify', 'falsify'
 


Sorry, doesn't get my vote (not that this is a democracy :) - I don't 
like that syntax at all.

Brad
May 26 2005
prev sibling next sibling parent reply Hasan Aljudy <hasan.aljudy gmail.com> writes:
Sam wrote:

 Ok then why not put 'isnull' and 'nullify' into a namespace or make them
 built-in?
 
 Then:
 
 if(isnull(a))
 ..
 else
 nullify(a);
 
 Granted it's not as small as the syntax with 'is' and 'null', but this
 eliminates the need for 'is' and 'null'.
 You see, to me my way is simpler:
 
 if(isnull(a)) // 1 isnull method, 1 argument
 if(a is null) // 1 is operator, 2 arguments (1 special keyword)
 
 nullify(a) // 1 method, 1 argument
 a = null   // 1 operator, 2 arguments (1 special keyword)
 
 if(!isnull(a)) // 1 ! operator, 1 isnull method, 1 argument
 if(a !== null) // 1 !== operator, 2 arguments (1 special keyword)
 
 
 I am for a 'not' keyword though!!  It's better than this '!' that carried over
 from c++!
 
 Recap of what I propose:
 
 Get rid of: 'null', 'true', 'false', '!', '!==', 'is'
 Add:        'not', 'isnull', 'nullify', 'truthify', 'falsify'
 
 ;-D
 


Sorry, doesn't get my vote.
Note that this is NOT Java, D is a systems programming language, not a 
scripting language or smalltalk. (note: I'm not implying that java is a 
scripting language)

BUT ...

You can always write the functions yourself ..

bool isnull( void *p )
{
     return (p is null);
}

void nullify(out void *p)
{
     p = null;
}

What's the problem with that? Why don't you write that yourself and stop 
using null if you don't like it?
May 26 2005
parent reply Sam <Sam_member pathlink.com> writes:
But see you've already gotten in trouble with the 'null' keyword!

You can't do:

a = null;

or

if(a == null)

So as you see, it just spreads confusion!

C++ is a systems language and it had no 'null' keyword, and nobody complained!
Some defined their own null constant.

I know D isn't C++ either, but if you're trying to invent the perfect language,
the perfect language at least in my opinion wouldn't have the 'null' keyword.


that they added them in purely for show and to make their languages look nice.

cout << null; // Exception!

In article <d755f4$2usp$1 digitaldaemon.com>, Hasan Aljudy says...

Sorry, doesn't get my vote.
Note that this is NOT Java, D is a systems programming language, not a 
scripting language or smalltalk. (note: I'm not implying that java is a 
scripting language)

BUT ...

You can always write the functions yourself ..

bool isnull( void *p )
{
     return (p is null);
}

void nullify(out void *p)
{
     p = null;
}

What's the problem with that? Why don't you write that yourself and stop 
using null if you don't like it?
May 26 2005
next sibling parent Tom S <h3r3tic remove.mat.uni.torun.pl> writes:
Sam wrote:

 But see you've already gotten in trouble with the 'null' keyword!
 
 You can't do:
 
 a = null;


No ? Why ?




believe
 that they added them in purely for show and to make their languages look nice.


Ok, you asked for it... Here it comes... WTF ?!



 cout << null; // Exception!


Exception ? It's C++. If null was #define'd to 0, it would print... "0", 
not raise an exception...


-- 
Tomasz Stachowiak  /+ a.k.a. h3r3tic +/
May 26 2005
prev sibling parent reply Hasan Aljudy <hasan.aljudy gmail.com> writes:
Sam wrote:

 But see you've already gotten in trouble with the 'null' keyword!
 
 You can't do:
 
 a = null;
 
 or
 
 if(a == null)


Where is the trouble if you are wrapping it? of course you HAVE to use 
it inside the function that wraps it .. what else would you expect?


 
 So as you see, it just spreads confusion!


I don't see that. Where is the confusion?
remember, you're probably the one who's gonna use "isnull" and "nullify" :P


 
 C++ is a systems language and it had no 'null' keyword, and nobody complained!
 Some defined their own null constant.



heh .. so are you saying D shouldn't have a 0?

I know you're not saying that, but if %99 percent of the people will 
define an alias for 'null' to zero, then what's the point?
The only way we could do what you want is to remove 0 alltogether.



 
 I know D isn't C++ either, but if you're trying to invent the perfect language,
 the perfect language at least in my opinion wouldn't have the 'null' keyword.


Why? huh? Why?
just because /you/ don't like it?



 

believe
 that they added them in purely for show and to make their languages look nice.



and 1.
0 and 1 are integers, true and false are booleans, you CANNOT implicitly 
convert ints to booleans in Java.
So it's not just for the language to look nice .. it's *strong* typing.
Also, null in java is *NOT* an alias for 0, infact, you can't compare 
references against null.

[Java code:]
Object x; //x is a reference, not an object
if( x == 0 ) //compiler error: x is not an int.
.....
[/Java code]


 cout << null; // Exception!


what the other guy said ..
<< is overloaded (I assume) for different types, so it's not like << 
expects objects.
when you pass a null, it's not a null pointer, it's a 0 integer.


 
 In article <d755f4$2usp$1 digitaldaemon.com>, Hasan Aljudy says...
 

Sorry, doesn't get my vote.
Note that this is NOT Java, D is a systems programming language, not a 
scripting language or smalltalk. (note: I'm not implying that java is a 
scripting language)

BUT ...

You can always write the functions yourself ..

bool isnull( void *p )
{
    return (p is null);
}

void nullify(out void *p)
{
    p = null;
}

What's the problem with that? Why don't you write that yourself and stop 
using null if you don't like it?
May 26 2005
parent Hasan Aljudy <hasan.aljudy gmail.com> writes:
ouch, typo:

I wrote:

 Also, null in java is *NOT* an alias for 0, infact, you can't compare 
 references against null.


I meant: "you can't compare references against 0"
May 26 2005
prev sibling parent Tom S <h3r3tic remove.mat.uni.torun.pl> writes:
Sam wrote:

 Recap of what I propose:
 
 Get rid of: 'null', 'true', 'false', '!', '!==', 'is'
 Add:        'not', 'isnull', 'nullify', 'truthify', 'falsify'



 The less keywords a language has, the simpler it bacomes and the easier it is
to
 learn.



So you propose a removal of 4 simple and short keywords and two 
operators and want to add 5 new keywords, some of which I'd wonder if 
are valid English words at all. That will make the language definitely 
easier to learn!

What's next ? Are you gonna tell us to remove char, wchar and dchar 
because they are sooooo redundant and then suggest adding char8859_1, 
char8859_2, char8859_3, charXXX, etc ? :\


-- 
Tomasz Stachowiak  /+ a.k.a. h3r3tic +/
May 26 2005
prev sibling parent =?ISO-8859-1?Q?Anders_F_Bj=F6rklund?= <afb algonet.se> writes:
Sam wrote:


But you would still need 'null' for pointers ?


 
 a.makenull();
 
 How about this???  I still believe the 'null' keyword can be deprecated!  :-O


You mean you would define some built-in properties for
regular pointers as well ? Like "isnull", for instance.

And even add methods to them ? Like this "makenull" here.
Without having it dereference it, like other such calls ?


Sounds kinda confusing. Especially with any pointers to structs...
(trying to guess which are built-in properties, which are fields ?)

And I really don't think "p.isnull()" is clearer than "p == null".
It might be a little clearer than "p", but that's another topic.

--anders

PS.
void* p; // not an object, as '== null' segfaults with those.
May 26 2005