How to simplify this LESS CSS Box-shadow mixin? (multiple shadows with "directions")

How to reduce this code (probably with a loop ?), to have a "function" which takes direction and number?

@dir = the wanted "direction"
@number = how many times I need a shadow (here 10 times)
@color = color of the shadow

Example (working, but not very easy to use) :

.perspective-box(@dir, @number, @color) when (@dir = se){
   -webkit-box-shadow:1px 1px 0 0 @color,
                      2px 2px 0 0 @color,
                      3px 3px 0 0 @color,
                      4px 4px 0 0 @color,
                      5px 5px 0 0 @color,
                      6px 6px 0 0 @color,
                      7px 7px 0 0 @color,
                      8px 8px 0 0 @color,
                      9px 9px 0 0 @color,
                      10px 10px 0 0 @color;
}

I have a @dir param which change the direction of shadows. In this example, I put @dir = se, where se = South East. This is the same thing for North West, North East, South West and South East.

How to avoid this…?

.perspective-box(@dir, @number, @color) when (@dir = ne){
   -webkit-box-shadow:10x North East shadow…
}

.perspective-box(@dir, @number, @color) when (@dir = nw){
   -webkit-box-shadow:10x North West shadow…
}

.perspective-box(@dir, @number, @color) when (@dir = sw){
   -webkit-box-shadow:10x South West shadow…
}

.perspective-box(@dir, @number, @color) when (@dir = se){
   -webkit-box-shadow:10x South East shadow…
}

Solution

No problem:

.text-shadow-3d(@x, @y, @index) when (@index > 0) {

    // Loop-de-loop.
    .text-shadow-3d(@x, @y, @index - 1);

    // The '+' after 'text-shadow' concatenates with comma.
    text-shadow+: @x*@index @y*@index 0 black;
}


.text-shadow-3d(1px, 1px, 5);

Result:

text-shadow: 1px 1px 0 #000000, 2px 2px 0 #000000, 3px 3px 0 #000000, 4px 4px 0 #000000, 5px 5px 0 #000000;

Docs:

http://lesscss.org/features/#loops-feature

http://lesscss.org/features/#merge-feature