digitalmars.D - foreach with enum

Thomas Mader (5/5) Jul 19 2007 I am just porting some of my little Java programs to D to get comfortabl...

BCS (5/17) Jul 19 2007 I think you are out of luck. Really enums should have a .tupleof proprie...

Kirk McDonald (7/30) Jul 19 2007 No need. You can iterate over tuples directly.

BCS (11/36) Jul 19 2007 however if the code can use a non tuple iteration, you wold be better of...

Extrawurst (2/8) Jul 19 2007
Vladimir Panteleev (9/14) Jul 19 2007 ble with the langugage and realized that I cannot use foreach with Enums...

BCS (2/19) Jul 19 2007 enum Color { Kreuz = 1, Pik = 2, Herz = 4, Karo = 8 }

Ameer Armaly (9/29) Jul 19 2007 Maybe make enums work with the in operator? I.E:

Bill Baxter (3/35) Jul 19 2007 enum Color { Kreuz = 1, None = uint.max }

Ameer Armaly (3/38) Jul 19 2007 Would do...? Pardon me but I don't see what you're getting at.

Bill Baxter (3/41) Jul 19 2007 Enumerating all values from 1 to uint.max could take a long long time.

Bill Baxter (6/48) Jul 19 2007 ... though I should add that I see nothing wrong with the idea of making...

Robert Fraser (5/11) Jul 19 2007 Hi Thomas,
renoX (10/16) Jul 23 2007 enum are woefully underpowered in D, you cannot print them correctly,

Thomas Mader <thezema gmail.com> writes:

I am just porting some of my little Java programs to D to get comfortable with
the langugage and realized that I cannot use foreach with Enums.
In Java I can do:
enum Color { Kreuz, Pik, Herz, Karo }
for(Color color : Color.values()) {}

AFAIK thats not possible in D yet.

Jul 19 2007

BCS <ao pathlink.com> writes:

Reply to Thomas,

 I am just porting some of my little Java programs to D to get
 comfortable with the langugage and realized that I cannot use foreach
 with Enums.
 
 In Java I can do:
 
 enum Color { Kreuz, Pik, Herz, Karo }
 
 for(Color color : Color.values()) {}
 
 AFAIK thats not possible in D yet.
 

I think you are out of luck. Really enums should have a .tupleof propriety. 
Then this would work:

foreach(A a; [A.tupleof]){...}

(if putting a tuple inside an array worked as expected)

Jul 19 2007

Kirk McDonald <kirklin.mcdonald gmail.com> writes:

BCS wrote:
 Reply to Thomas,
 
 I am just porting some of my little Java programs to D to get
 comfortable with the langugage and realized that I cannot use foreach
 with Enums.

 In Java I can do:

 enum Color { Kreuz, Pik, Herz, Karo }

 for(Color color : Color.values()) {}

 AFAIK thats not possible in D yet.

 
 I think you are out of luck. Really enums should have a .tupleof 
 propriety. Then this would work:
 
 foreach(A a; [A.tupleof]){...}
 
 (if putting a tuple inside an array worked as expected)
 
 

No need. You can iterate over tuples directly.

-- 
Kirk McDonald
http://kirkmcdonald.blogspot.com
Pyd: Connecting D and Python
http://pyd.dsource.org

Jul 19 2007

BCS <ao pathlink.com> writes:

Reply to Kirk,

 BCS wrote:
 
 Reply to Thomas,
 
 I am just porting some of my little Java programs to D to get
 comfortable with the langugage and realized that I cannot use
 foreach with Enums.
 
 In Java I can do:
 
 enum Color { Kreuz, Pik, Herz, Karo }
 
 for(Color color : Color.values()) {}
 
 AFAIK thats not possible in D yet.
 

 I think you are out of luck. Really enums should have a .tupleof
 propriety. Then this would work:
 
 foreach(A a; [A.tupleof]){...}
 
 (if putting a tuple inside an array worked as expected)
 

 No need. You can iterate over tuples directly.
 


however if the code can use a non tuple iteration, you wold be better of 
with the array version because it only generates the code once.


foreach(i;T!(1,2,3)
{
	writef(i);
}

goes to

	writef(1);
	writef(2);
	writef(3);

Jul 19 2007

Extrawurst <spam extrawurst.org> writes:

that would be a very nice feature indeed


Thomas Mader schrieb:
 I am just porting some of my little Java programs to D to get comfortable with
the langugage and realized that I cannot use foreach with Enums.
 In Java I can do:
 enum Color { Kreuz, Pik, Herz, Karo }
 for(Color color : Color.values()) {}

 AFAIK thats not possible in D yet.

Jul 19 2007

"Vladimir Panteleev" <thecybershadow gmail.com> writes:

On Thu, 19 Jul 2007 23:14:59 +0300, Thomas Mader <thezema gmail.com> wro=
te:

 I am just porting some of my little Java programs to D to get comforta=

ble with the langugage and realized that I cannot use foreach with Enums=
.
 In Java I can do:
 enum Color { Kreuz, Pik, Herz, Karo }
 for(Color color : Color.values()) {}

 AFAIK thats not possible in D yet.

for (Color color=3DColor.min; color<=3DColor.max; color++)
	writefln(color);

-- =

Best regards,
  Vladimir                          mailto:thecybershadow gmail.com

Jul 19 2007

BCS <ao pathlink.com> writes:

Reply to Vladimir,

 On Thu, 19 Jul 2007 23:14:59 +0300, Thomas Mader <thezema gmail.com>
 wrote:
 
 I am just porting some of my little Java programs to D to get
 comfortable with the langugage and realized that I cannot use foreach
 with Enums.
 
 In Java I can do:
 
 enum Color { Kreuz, Pik, Herz, Karo }
 
 for(Color color : Color.values()) {}
 
 AFAIK thats not possible in D yet.
 

 for (Color color=Color.min; color<=Color.max; color++)
 writefln(color);

enum Color { Kreuz = 1, Pik = 2, Herz = 4, Karo = 8 }

Jul 19 2007

"Ameer Armaly" <ameer_armaly hotmail.com> writes:

"BCS" <ao pathlink.com> wrote in message 
news:ce0a3343bffb8c99827432b23b4 news.digitalmars.com...
 Reply to Vladimir,

 On Thu, 19 Jul 2007 23:14:59 +0300, Thomas Mader <thezema gmail.com>
 wrote:

 I am just porting some of my little Java programs to D to get
 comfortable with the langugage and realized that I cannot use foreach
 with Enums.

 In Java I can do:

 enum Color { Kreuz, Pik, Herz, Karo }

 for(Color color : Color.values()) {}

 AFAIK thats not possible in D yet.

 for (Color color=Color.min; color<=Color.max; color++)
 writefln(color);

 enum Color { Kreuz = 1, Pik = 2, Herz = 4, Karo = 8 }

Maybe make enums work with the in operator? I.E:
enum Color { Kreuz = 1, Pik = 2, Herz = 4, Karo = 8 }
for(int i = Color.min; i <= Color.max; ++i)
{
if( i in Color)
writefln(i);
}

Jul 19 2007

Bill Baxter <dnewsgroup billbaxter.com> writes:

Ameer Armaly wrote:
 "BCS" <ao pathlink.com> wrote in message 
 news:ce0a3343bffb8c99827432b23b4 news.digitalmars.com...
 Reply to Vladimir,

 On Thu, 19 Jul 2007 23:14:59 +0300, Thomas Mader <thezema gmail.com>
 wrote:

 I am just porting some of my little Java programs to D to get
 comfortable with the langugage and realized that I cannot use foreach
 with Enums.

 In Java I can do:

 enum Color { Kreuz, Pik, Herz, Karo }

 for(Color color : Color.values()) {}

 AFAIK thats not possible in D yet.

 for (Color color=Color.min; color<=Color.max; color++)
 writefln(color);

 enum Color { Kreuz = 1, Pik = 2, Herz = 4, Karo = 8 }

 Maybe make enums work with the in operator? I.E:
 enum Color { Kreuz = 1, Pik = 2, Herz = 4, Karo = 8 }
 for(int i = Color.min; i <= Color.max; ++i)
 {
 if( i in Color)
 writefln(i);
 }
 
 

enum Color { Kreuz = 1, None = uint.max }

--bb

Jul 19 2007

"Ameer Armaly" <ameer_armaly hotmail.com> writes:

"Bill Baxter" <dnewsgroup billbaxter.com> wrote in message 
news:f7p06o$j56$1 digitalmars.com...
 Ameer Armaly wrote:
 "BCS" <ao pathlink.com> wrote in message 
 news:ce0a3343bffb8c99827432b23b4 news.digitalmars.com...
 Reply to Vladimir,

 On Thu, 19 Jul 2007 23:14:59 +0300, Thomas Mader <thezema gmail.com>
 wrote:

 I am just porting some of my little Java programs to D to get
 comfortable with the langugage and realized that I cannot use foreach
 with Enums.

 In Java I can do:

 enum Color { Kreuz, Pik, Herz, Karo }

 for(Color color : Color.values()) {}

 AFAIK thats not possible in D yet.

 for (Color color=Color.min; color<=Color.max; color++)
 writefln(color);

 enum Color { Kreuz = 1, Pik = 2, Herz = 4, Karo = 8 }

 Maybe make enums work with the in operator? I.E:
 enum Color { Kreuz = 1, Pik = 2, Herz = 4, Karo = 8 }
 for(int i = Color.min; i <= Color.max; ++i)
 {
 if( i in Color)
 writefln(i);
 }

 enum Color { Kreuz = 1, None = uint.max }

Would do...? Pardon me but I don't see what you're getting at.
 --bb

Jul 19 2007

Bill Baxter <dnewsgroup billbaxter.com> writes:

Ameer Armaly wrote:
 "Bill Baxter" <dnewsgroup billbaxter.com> wrote in message 
 news:f7p06o$j56$1 digitalmars.com...
 Ameer Armaly wrote:
 "BCS" <ao pathlink.com> wrote in message 
 news:ce0a3343bffb8c99827432b23b4 news.digitalmars.com...
 Reply to Vladimir,

 On Thu, 19 Jul 2007 23:14:59 +0300, Thomas Mader <thezema gmail.com>
 wrote:

 I am just porting some of my little Java programs to D to get
 comfortable with the langugage and realized that I cannot use foreach
 with Enums.

 In Java I can do:

 enum Color { Kreuz, Pik, Herz, Karo }

 for(Color color : Color.values()) {}

 AFAIK thats not possible in D yet.

 for (Color color=Color.min; color<=Color.max; color++)
 writefln(color);

 enum Color { Kreuz = 1, Pik = 2, Herz = 4, Karo = 8 }

 Maybe make enums work with the in operator? I.E:
 enum Color { Kreuz = 1, Pik = 2, Herz = 4, Karo = 8 }
 for(int i = Color.min; i <= Color.max; ++i)
 {
 if( i in Color)
 writefln(i);
 }

 enum Color { Kreuz = 1, None = uint.max }

 Would do...? Pardon me but I don't see what you're getting at.

Enumerating all values from 1 to uint.max could take a long long time.

--bb

Jul 19 2007

Bill Baxter <dnewsgroup billbaxter.com> writes:

Bill Baxter wrote:
 Ameer Armaly wrote:
 "Bill Baxter" <dnewsgroup billbaxter.com> wrote in message 
 news:f7p06o$j56$1 digitalmars.com...
 Ameer Armaly wrote:
 "BCS" <ao pathlink.com> wrote in message 
 news:ce0a3343bffb8c99827432b23b4 news.digitalmars.com...
 Reply to Vladimir,

 On Thu, 19 Jul 2007 23:14:59 +0300, Thomas Mader <thezema gmail.com>
 wrote:

 I am just porting some of my little Java programs to D to get
 comfortable with the langugage and realized that I cannot use 
 foreach
 with Enums.

 In Java I can do:

 enum Color { Kreuz, Pik, Herz, Karo }

 for(Color color : Color.values()) {}

 AFAIK thats not possible in D yet.

 for (Color color=Color.min; color<=Color.max; color++)
 writefln(color);

 enum Color { Kreuz = 1, Pik = 2, Herz = 4, Karo = 8 }

 Maybe make enums work with the in operator? I.E:
 enum Color { Kreuz = 1, Pik = 2, Herz = 4, Karo = 8 }
 for(int i = Color.min; i <= Color.max; ++i)
 {
 if( i in Color)
 writefln(i);
 }

 enum Color { Kreuz = 1, None = uint.max }

 Would do...? Pardon me but I don't see what you're getting at.

 
 Enumerating all values from 1 to uint.max could take a long long time.

... though I should add that I see nothing wrong with the idea of making 
'in' work for enums itself.  That would be nice.  But it's not a 
replacement for a way to iterate over all values in an enum, which is 
what the thread is about.

--bb

Jul 19 2007

Robert Fraser <fraserofthenight gmail.com> writes:

Thomas Mader Wrote:

 I am just porting some of my little Java programs to D to get comfortable with
the langugage and realized that I cannot use foreach with Enums.
 In Java I can do:
 enum Color { Kreuz, Pik, Herz, Karo }
 for(Color color : Color.values()) {}
 
 AFAIK thats not possible in D yet.

Hi Thomas,

D enums are effectively just collections of integral constants, optionally with
a namespace. Java enums are a lot more powerful (though I think they go a
little bit overboard -- if you're adding methods to your enum members, isn't it
about time you made them a true class hierarchy?).

I created a mixinable template generating an enum-like struct that overcomes
many of the shortcomings of D's enum (there's a "toString" method to get the
name, a "members" static method to get a collection of all the members (so you
can loop through them just fine), and it's possible to check if a particular
member exists by using an is expression). I've also created a "BitSwitch"
template that's a bit harder to work with, but with the same advantages.
They're just structs with a single uint member, so they're no less efficient
than enums are now.

I can post both of them if you want, but others have probably come up with
(better) implementations (I think someone on learn mentioned they hand done
something similar).

Jul 19 2007

renoX <renosky free.fr> writes:

Thomas Mader a �crit :
 I am just porting some of my little Java programs to D to get
 comfortable with the langugage and realized that I cannot use foreach
 with Enums. In Java I can do: enum Color { Kreuz, Pik, Herz, Karo } 
 for(Color color : Color.values()) {}
 
 AFAIK thats not possible in D yet.

enum are woefully underpowered in D, you cannot print them correctly,
cannot iterate over them,.. It's a pity because I think that it's a very
important structure (well less than array literals, but still important).

I was inspired by Robert to make also a templated enum version to print 
them, (and I'm probably not the only one) but it's a hack..

With macros, hopefully these hacks could become 'less ugly' enough that
we could integrate them in a library..

Regards,
renoX

Jul 23 2007

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