Two-dimensional slices in D

Dennis Ritchie via Digitalmars-d-learn digitalmars-d-learn at puremagic.com
Tue Apr 14 07:21:39 PDT 2015


Hi,
Is it possible to somehow shorter turn to slice on D? Maybe you 
can use tuples?

F#:
-----
printfn "%A" xs.[4 .. 7, 4 .. 9]
-----

D:
-----
writeln([a[4][4 .. $], a[5][4 .. $], a[6][4 .. $], a[7][4 .. $]]);
-----

F#:
-----
let xs = Array2D.init 10 10 (fun x y -> x * 10 + y)
printfn "[4 .. 7, 6 .. 9] = \n%A" xs.[4 .. 7, 4 .. 9]
-----
http://ideone.com/jjWlXQ

D:
-----
import std.stdio;

void main() {
	
	auto a = [
		[0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
		[10, 11, 12, 13, 14, 15, 16, 17, 18, 19],
		[20, 21, 22, 23, 24, 25, 26, 27, 28, 29],
		[30, 31, 32, 33, 34, 35, 36, 37, 38, 39],
		[40, 41, 42, 43, 44, 45, 46, 47, 48, 49],
		[50, 51, 52, 53, 54, 55, 56, 57, 58, 59],
		[60, 61, 62, 63, 64, 65, 66, 67, 68, 69],
		[70, 71, 72, 73, 74, 75, 76, 77, 78, 79],
		[80, 81, 82, 83, 84, 85, 86, 87, 88, 89],
		[90, 91, 92, 93, 94, 95, 96, 97, 98, 99]
	];

	foreach (i; 4 .. 8)
		writeln(a[i][4 .. $]);

     /*	[44, 45, 46, 47, 48, 49]
	[54, 55, 56, 57, 58, 59]
	[64, 65, 66, 67, 68, 69]
	[74, 75, 76, 77, 78, 79]  */

	writefln("[%([%(%s, %)]%|\n %)]", [a[4][4 .. $], a[5][4 .. $], 
a[6][4 .. $], a[7][4 .. $]]);

     /* [[44, 45, 46, 47, 48, 49]
	[54, 55, 56, 57, 58, 59]
	[64, 65, 66, 67, 68, 69]
	[74, 75, 76, 77, 78, 79]] */
}
-----
http://ideone.com/ACOcHJ


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