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digitalmars.D.learn - Switching rows with columns

reply "Tanel =?UTF-8?B?VGFnYXbDpGxpIg==?= <tanel58 hotmail.com> writes:
I have a range of ranges and need to change it so the elements 
are column-aligned instead of row-aligned.

For example,
[[1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]]
would change into
[[1, 4, 7],
  [2, 5, 8],
  [3, 6, 0]].

Can I even do this with ranges, and if so, how?
Jul 04 2015
parent reply "Marc =?UTF-8?B?U2Now7x0eiI=?= <schuetzm gmx.net> writes:
On Saturday, 4 July 2015 at 15:28:56 UTC, Tanel Tagaväli wrote:
 I have a range of ranges and need to change it so the elements 
 are column-aligned instead of row-aligned.

 For example,
 [[1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]]
 would change into
 [[1, 4, 7],
  [2, 5, 8],
  [3, 6, 0]].

 Can I even do this with ranges, and if so, how?
Try std.range.transposed: http://dlang.org/phobos/std_range.html#.transposed
Jul 04 2015
parent reply "Tanel =?UTF-8?B?VGFnYXbDpGxpIg==?= <tanel58 hotmail.com> writes:
On Saturday, 4 July 2015 at 16:29:44 UTC, Marc Schütz wrote:
 Try std.range.transposed:
 http://dlang.org/phobos/std_range.html#.transposed
Does this work with user-defined types? I defined two structs that implement the InputRange(possibly ForwardRange) interface, an integer range and a range of those integer ranges. DMD tells me the "transposed" template cannot deduce function from the arguments, which is a range of integer ranges. The template does, however, work on a two-dimensional array. The "save" method is implemented using a simple "return this", could this be to blame?
Jul 04 2015
parent reply "Marc =?UTF-8?B?U2Now7x0eiI=?= <schuetzm gmx.net> writes:
On Sunday, 5 July 2015 at 00:18:18 UTC, Tanel Tagaväli wrote:
 On Saturday, 4 July 2015 at 16:29:44 UTC, Marc Schütz wrote:
 Try std.range.transposed:
 http://dlang.org/phobos/std_range.html#.transposed
Does this work with user-defined types? I defined two structs that implement the InputRange(possibly ForwardRange) interface, an integer range and a range of those integer ranges. DMD tells me the "transposed" template cannot deduce function from the arguments, which is a range of integer ranges. The template does, however, work on a two-dimensional array. The "save" method is implemented using a simple "return this", could this be to blame?
This should be fine. Which of the ranges is the ForwardRange? It should be the range-of-ranges. You can check which of the template constraints fails: import std.range; alias RangeOfRanges = typeof(myRangeOfRanges); pragma(msg, isForwardRange!RangeOfRanges); pragma(msg, isInputRange!(ElementType!RangeOfRanges)); pragma(msg, hasAssignableElements!RangeOfRanges); Maybe it's the last condition, `hasAssignableElements`. I don't know whether that one is really necessary...
Jul 05 2015
parent "Tanel =?UTF-8?B?VGFnYXbDpGxpIg==?= <tanel58 hotmail.com> writes:
On Sunday, 5 July 2015 at 11:35:14 UTC, Marc Schütz wrote:
 Maybe it's the last condition, `hasAssignableElements`. I don't 
 know whether that one is really necessary...
It probably is. The last check returned false. Since I already would have to implement "r.front = ", I'll just use arrays. Thanks for the help.
Jul 05 2015