Question about a possible feature request.

[jaberwacky]

I'm sure this has been asked before but again I don't really know how to search for this because I don't know what it would be called.

I was thinking that because we can do this:

For $var in $array
  ...
Next

Would it make a good feature request to ask for this:

For $var1 in $array1, $var2 in $array2, ...
  ...
Next

Or whatever the best syntax would be?

Edited January 16, 2014 by jaberwacky

[guinness]

Is your request limited to just For...In loops?

[jaberwacky]

Well, that was the original intent but if you have anything to offer please do so.

Edited January 16, 2014 by jaberwacky

[jchd]

N-dimensional collection For loop?

What would that sugar bring that we don't already have (beyond saving few keystrokes)?

For $var1 In $collection1
    For $var2 In $collection2
...
    Next
Next

[jaberwacky]

For $var1 In $collection1     
    For $var2 In $collection2 
        ...     
    Next 
Next

I think it's a little different from nested loops.  The inner loop will run through $collection2 on the first $var1, and then on the 2nd $var1 it owuld run through $collection2 again, repeat.

The idea I have is to have them both go through the collections at the same time.

Here is the difference in output in our snippets:

Local $array1[5] = [1, 2, 3, 4, 5]

Local $array2[5] = ['a', 'b,' 'c', 'd', 'e']

For $var1 in $array1, $var2 in $array2   
  ConsoleWrite($var1 & @TAB & $var2 & @CRLF)
Next

1 a
2 b
3 c
4 d
5 e

Local $collection1[5] = [1, 2, 3, 4, 5]

Local $collection2[5] = ['a', 'b,' 'c', 'd', 'e']

For $var1 In $collection1     
  For $var2 In $collection2
    ConsoleWrite($var1 & @TAB & $var2 & @CRLF)
  Next 
Next

1 a
1 b
1 c
1 d
1 e

2 a
2 b
2 c
2 d
2 e

3 a
3 b
3 c
3 d
3 e

4 a
4 b
4 c
4 d
4 e

5 a
5 b
5 c
5 d
5 e

[jchd]

Ha, you intended that to be a N-parallel collection For loop, then, or an inner join on implicit iterators.

That will need to solve the obvious pitfall of collections having different cardinalities:

Local $array1 = [1, 2, 3, 4, 5]

Local $array2 = ['a', 'b,' 'c', 'd']

For $var1 in $array1, $var2 in $array2   
  ConsoleWrite($var1 & @TAB & $var2 & @CRLF)
Next

1 a
2 b
3 c
4 d
what to do next? stop here or raise error or:
5 Null

Anyway I don't see much use for such a construct, but you certainly have something in mind.

[jaberwacky]

hhhrrrrnnnngggg, why didn't that ever occur to me??!?!?

Okies, get back to work everyone.  Nothing to see here.

Thanks jchd.  =D

[Richard Robertson]

I'm not familiar with any language that actually allows parallel looping like that. I've seen pairs of objects being enumerated, but never objects from different collections at the same time.

Can you give me an example where you've seen this before?

[jaberwacky]

I don't think I have (and for good reason it turns out).

Edited January 18, 2014 by jaberwacky

[Mat]

This should be possible though:

Local $a[][] = [[1, "A"], [2, "B"], [3, "C"], [4, "D"], [5, "E"]]

For $n, $c in $a
    ConsoleWrite($n & " " & $a & @LF)
Next

[jaberwacky]

Absolutely, that would be pretty freakin' cool.

[Richard Robertson]

 

This should be possible though:

Local $a[][] = [[1, "A"], [2, "B"], [3, "C"], [4, "D"], [5, "E"]]

For $n, $c in $a
    ConsoleWrite($n & " " & $a & @LF)
Next

Yes, this is something I have seen plenty of times.

[jchd]

The possibility of accessing a partial-dimensional sub-array as a first-class array by itself would be much more powerful and useful in many more situations than just sugar in a For loop:

Local $a[3][2][2] = [ _
    [ _
        [ "A_000", "A_001" ], _
        [ "A_010", "A_011" ] _
    ], _
    [ _
        [ "A_100", "A_101" ], _
        [ "A_110", "A_111" ] _
    ], _
    [ _
        [ "A_200", "A_201" ], _
        [ "A_210", "A_211" ] _
    ] _
]

Local $b = $a[1]    ; should be a 2D array
;
;   A_100   A_101
;
;   A_110   A_101

Local $c = $a[1][1] ; should be a 1D array
;
;   A_110   A_111
;

For $elem In $a[2][0]
    ConsoleWrite($elem[0] & ', ' & $elem[1] & @LF)
Next
;    A_200, A_201