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D - Yet another property idea

reply Russell Borogove <kaleja estarcion.com> writes:
The property .symbol produces a text string corresponding
to the identifier it's applied to:

    int foo = 3;

    printf( "%s = %d\n", foo.symbol, foo );  // print "foo = 3"

This is purely a compile time operation, generating string
representations only on demand.

This kind of thing is indispendable for debugging, and
valuable in general use as well. IMO, it offers a slight
improvement on the "Arrays that parallel an enum"
suggestion in:

  http://www.digitalmars.com/d/ctod.html#arrayenum

-RB
May 19 2002
parent reply "Walter" <walter digitalmars.com> writes:
"Russell Borogove" <kaleja estarcion.com> wrote in message
news:3CE82DF2.70608 estarcion.com...

 The property .symbol produces a text string corresponding
 to the identifier it's applied to:

     int foo = 3;

     printf( "%s = %d\n", foo.symbol, foo );  // print "foo = 3"

 This is purely a compile time operation, generating string
 representations only on demand.


I might be missing something, but what is the advantage over:

   printf( "%s = %d\n", "foo", foo );  // print "foo = 3"
May 19 2002
parent reply Jonathan Andrew <jon ece.arizona.edu> writes:
Walter wrote:


 "Russell Borogove" <kaleja estarcion.com> wrote in message
 news:3CE82DF2.70608 estarcion.com...

 The property .symbol produces a text string corresponding
 to the identifier it's applied to:

     int foo = 3;

     printf( "%s = %d\n", foo.symbol, foo );  // print "foo = 3"

 This is purely a compile time operation, generating string
 representations only on demand.


 I might be missing something, but what is the advantage over:

    printf( "%s = %d\n", "foo", foo );  // print "foo = 3"


I suppose you could write a generic debug function i.e.

void debug(int var)
{
  printf("%s = %d\n", var.symbol, var);
}

debug(foo);

There are probably a lot of other uses, I agree that it doesn't look too
helpful at first, but there
are probably lots of other tricks you could do with it. (Just as long as
it's read only!!)
-Jon
May 20 2002
parent reply "Pavel Minayev" <evilone omen.ru> writes:
"Jonathan Andrew" <jon ece.arizona.edu> wrote in message
news:3CE921D7.CE5E4334 ece.arizona.edu...


 I suppose you could write a generic debug function i.e.

 void debug(int var)
 {
   printf("%s = %d\n", var.symbol, var);
 }

 debug(foo);


Being resolved at compile time, it'd write "var = 666" (since
var.symbol would probably give "var").
May 20 2002
next sibling parent reply "OddesE" <OddesE_XYZ hotmail.com> writes:
"Pavel Minayev" <evilone omen.ru> wrote in message
news:acbj3h$1263$1 digitaldaemon.com...

 "Jonathan Andrew" <jon ece.arizona.edu> wrote in message
 news:3CE921D7.CE5E4334 ece.arizona.edu...


 I suppose you could write a generic debug function i.e.

 void debug(int var)
 {
   printf("%s = %d\n", var.symbol, var);
 }

 debug(foo);


 Being resolved at compile time, it'd write "var = 666" (since
 var.symbol would probably give "var").



class Foo
{
  int i;
}

class Bar: public Foo
{
}

Foo obj = new Bar;
obj.i = 3;
printf( "%s == %d\n", obj.symbol, obj.i);

// prints "Bar == 3"


So maybe slightly more helpfull than you might think
at first...

--
Stijn
OddesE_XYZ hotmail.com
http://OddesE.cjb.net
_________________________________________________
Remove _XYZ from my address when replying by mail
May 20 2002
next sibling parent Patrick Down <pat codemoon.com> writes:
"OddesE" <OddesE_XYZ hotmail.com> wrote in news:acboqg$17gb$1
 digitaldaemon.com:


 "Pavel Minayev" <evilone omen.ru> wrote in message
 news:acbj3h$1263$1 digitaldaemon.com...

 "Jonathan Andrew" <jon ece.arizona.edu> wrote in message


 
 Foo obj = new Bar;
 obj.i = 3;
 printf( "%s == %d\n", obj.symbol, obj.i);
 
 // prints "Bar == 3"
 
 


obj.classinfo.name
May 20 2002
prev sibling next sibling parent reply "Pavel Minayev" <evilone omen.ru> writes:
"OddesE" <OddesE_XYZ hotmail.com> wrote in message
news:acboqg$17gb$1 digitaldaemon.com...


 class Foo
 {
   int i;
 }

 class Bar: public Foo
 {
 }

 Foo obj = new Bar;
 obj.i = 3;
 printf( "%s == %d\n", obj.symbol, obj.i);

 // prints "Bar == 3"


Actually, it'd print "obj" (it's the name of the _symbol_,
and not its type).

For typename, use classinfo.name.
May 20 2002
parent "OddesE" <OddesE_XYZ hotmail.com> writes:
"Pavel Minayev" <evilone omen.ru> wrote in message
news:accfor$1rop$1 digitaldaemon.com...

 "OddesE" <OddesE_XYZ hotmail.com> wrote in message
 news:acboqg$17gb$1 digitaldaemon.com...


 class Foo
 {
   int i;
 }

 class Bar: public Foo
 {
 }

 Foo obj = new Bar;
 obj.i = 3;
 printf( "%s == %d\n", obj.symbol, obj.i);

 // prints "Bar == 3"


 Actually, it'd print "obj" (it's the name of the _symbol_,
 and not its type).

 For typename, use classinfo.name.




You are right ofcourse!
Sorry I was confused.


--
Stijn
OddesE_XYZ hotmail.com
http://OddesE.cjb.net
_________________________________________________
Remove _XYZ from my address when replying by mail
May 21 2002
prev sibling parent "Sean L. Palmer" <seanpalmer earthlink.net> writes:
So does obj.symbol give its type name, or its value's name?  Variable name
or type name?  Or perhaps both i.e. "Bar[]* foo"

Sean

"OddesE" <OddesE_XYZ hotmail.com> wrote in message
news:acboqg$17gb$1 digitaldaemon.com...

 "Pavel Minayev" <evilone omen.ru> wrote in message
 news:acbj3h$1263$1 digitaldaemon.com...

 "Jonathan Andrew" <jon ece.arizona.edu> wrote in message
 news:3CE921D7.CE5E4334 ece.arizona.edu...


 I suppose you could write a generic debug function i.e.

 void debug(int var)
 {
   printf("%s = %d\n", var.symbol, var);
 }

 debug(foo);


 Being resolved at compile time, it'd write "var = 666" (since
 var.symbol would probably give "var").



 class Foo
 {
   int i;
 }

 class Bar: public Foo
 {
 }

 Foo obj = new Bar;
 obj.i = 3;
 printf( "%s == %d\n", obj.symbol, obj.i);

 // prints "Bar == 3"


 So maybe slightly more helpfull than you might think
 at first...
May 21 2002
prev sibling parent Jonathan Andrew <jon ece.arizona.edu> writes:
Pavel Minayev wrote:


 "Jonathan Andrew" <jon ece.arizona.edu> wrote in message
 news:3CE921D7.CE5E4334 ece.arizona.edu...


 I suppose you could write a generic debug function i.e.

 void debug(int var)
 {
   printf("%s = %d\n", var.symbol, var);
 }

 debug(foo);


 Being resolved at compile time, it'd write "var = 666" (since
 var.symbol would probably give "var").


Hmm, good point.
 -Jon
May 21 2002