Revamping associative arrays

[Piotrek]

Bill Baxter pisze:
> On Sun, Oct 18, 2009 at 1:12 PM, Piotrek <starpit at tlen.pl> wrote:
>> Bill Baxter pisze:
>>> I think the default should be to iterate over whatever 'in' looks at.
>>>
>> I was almost convinced, because that rule has a sense. But treating normal
>> arrays and associative array has more sense to me.
>>
>>
>> fun (SomeObject object) {
>> foreach (element;object.arr1){ //normal, but how do I know at first look
>> //just do something with element
>> }
>>
>> foreach (element;object.arr2){ // assoc, but how do I know at first look
>> //just do something with element hopefully not index
>> }
> 
> That sounds like an argument that there should be no default, because
> either way it's not clear whether you're iterating over keys or
> values. 


Really?! That wasn't my intention :) In both cases I wish it were values ;)

 > Just get rid of the the one-argument foreach over AAs altogether and 
force the user to be
 > explicit about it.

I wouldn't do so. Would anybody do an error by thinking that foreach 
(elem,table) should iterate over keys?

Maybe I'm not thinking correctly but for me an assoc array is just an 
array with additional key (index) features thanks to which I save space 
and/or have more indexing method than only integers.


e.g.

Normal array

No.       Item
0	George
1	Fred
2	Dany
3	Lil

Index/key is infered from position (offset)


Now Assoc array:

No.	Item
10	Lindsey
21	Romeo
1001	C-Jay

Or
No.	Item
first	Europe
second	South America
third	Australia

Or
Names occurrence frequency:

No. Item
Andy	21
John	23
Kate	12

And the only difference is the need for using a hash function for value 
lookup (calculate position) which should not bother a user when he 
doesn't care.

Then when you ask somebody to iterate over the tables, what he will do 
almost for certain? If it would be me, you know... values all the time. 
Even for last example most important values are those numbers (despite 
in this case they're meaningless without keys).

Cheers
Piotrek