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digitalmars.D.learn - foreach change for multi-dimensional data

reply ixid <nuaccount gmail.com> writes:
This is an idle thought hence putting it on the Learn-level 
forum. An idea struck me for foreach to make working with more 
complicated data types or heavily nested data easier.


	uint[][] a = [[1,2,3],[4,5,6]];

	foreach(uint[] b; a)
		b.writeln;
	

At present you can specify the type of 'b' in this example. If 
you want to iterate over each uint you have to write (and 
obviously you can omit the type for 'b' and 'c'):

	
	foreach(uint[] b; a)
		foreach(uint c; b)
			c.writeln;
	
It would be nice if you could do something like this:

	foreach(uint c; a)
		c.writeln;

Where it will take the ForeachType of 'a' until it finds a match 
to the type of 'c' and iterate over all that data. It would make 
it much less messy to apply a function that takes uint to all the 
data rather than having to nest loops or map maps.
Jan 28
parent reply =?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:
On 01/28/2016 05:33 AM, ixid wrote:
 This is an idle thought hence putting it on the Learn-level forum. An
 idea struck me for foreach to make working with more complicated data
 types or heavily nested data easier.


      uint[][] a = [[1,2,3],[4,5,6]];
[...]
 It would be nice if you could do something like this:

      foreach(uint c; a)
          c.writeln;
It looks like Solomon E's recent collapse() is what we need here: http://forum.dlang.org/post/xihlsfgfpykdvmvrggyr forum.dlang.org foreach(c; a.collapse) // ... Ali
Jan 28
parent ixid <nuaccount gmail.com> writes:
On Thursday, 28 January 2016 at 15:38:20 UTC, Ali Çehreli wrote:
 On 01/28/2016 05:33 AM, ixid wrote:
 This is an idle thought hence putting it on the Learn-level
forum. An
 idea struck me for foreach to make working with more
complicated data
 types or heavily nested data easier.


      uint[][] a = [[1,2,3],[4,5,6]];
[...]
 It would be nice if you could do something like this:

      foreach(uint c; a)
          c.writeln;
It looks like Solomon E's recent collapse() is what we need here: http://forum.dlang.org/post/xihlsfgfpykdvmvrggyr forum.dlang.org foreach(c; a.collapse) // ... Ali
That's a much more limited version of what I'm suggesting in that it just collapses until something isn't an array any more, sometimes you might only want to collapse two levels and get up with something that's still an array type or you will be getting members in struct that's in an array. I've written something similar for myself that will collapse until a provided type is matched or the first argument type of a provided function is matched and apply the function.
Jan 28