// mixins to call inside loop
.applyMixin('gridSpan', @index) {
	#grid > .span-width(@index);
}

.applyMixin('gridPush', @index) {
	#grid > .indent(@index);
}

.applyMixin('gridPull', @index) {
	#grid > .indent(-@index);
}

// helper class, will never show up in resulting css
// will be called as long the index is above 0
.loop (@index, @class: item, @mixin: '') when (@index > 0) {

	// create the actual css selector
        // use (~'.@{class}_@{index}') for LESS version < 1.4
	.@{class}_@{index} {
		// call styles through mixin
		.applyMixin(@mixin, @index);
	}

	// next iteration
	.loop(@index - 1, @class, @mixin);
}

// end the loop when index is 0
.loop (0) {}

// mixins to call inside loop
.applyMixin('gridSpan', @index) {
	#grid > .span-width(@index);
}

.applyMixin('gridPush', @index) {
	#grid > .indent(@index);
}

.applyMixin('gridPull', @index) {
	#grid > .indent(-@index);
}

// helper class, will never show up in resulting css
// will be called as long the index is above 0
.loop (@index, @class: 'item', @mixin: '') when (@index > 0) {

	// create the actual css selector
        // use (~'.@{class}_@{index}') for LESS version < 1.4
	.@{class}_@{index} {
		// call styles through mixin
		.applyMixin(@mixin, @index);
	}

	// next iteration
	.loop(@index - 1, @class, @mixin);
}

// end the loop when index is 0
.loop (0) {}

// mixins to call inside loop
.applyMixin('gridSpan', @index) {
	#grid > .span-width(@index);
}

.applyMixin('gridPush', @index) {
	#grid > .indent(@index);
}

.applyMixin('gridPull', @index) {
	#grid > .indent(-@index);
}

// helper class, will never show up in resulting css
// will be called as long the index is above 0
.loop (@index, @class: 'item', @mixin: '') when (@index > 0) {

	// create the actual css selector
	.@{class}_@{index} {
		// call styles through mixin
		.applyMixin(@mixin, @index);
	}

	// next iteration
	.loop(@index - 1, @class, @mixin);
}

// end the loop when index is 0
.loop (0) {}

// mixins to call inside loop
.applyMixin('gridSpan', @index) {
	#grid > .span-width(@index);
}

.applyMixin('gridPush', @index) {
	#grid > .indent(@index);
}

.applyMixin('gridPull', @index) {
	#grid > .indent(-@index);
}

// helper class, will never show up in resulting css
// will be called as long the index is above 0
.loop (@index, @class: 'item', @mixin: '') when (@index > 0) {

	// create the actual css selector, example will result in
	// .myclass_30, .myclass_28, .... , .myclass_1
	(~'.@{class}-@{index}') {
		// your resulting css
		.applyMixin(@mixin, @index);
	}

	// next iteration
	.loop(@index - 1, @class, @mixin);
}

// end the loop when index is 0
.loop (0) {}

Generate numbered classes and apply variable mixins.
Base from [http://blog.thehippo.de/2012/04/programming/do-a-loop-with-less-css/](http://blog.thehippo.de/2012/04/programming/do-a-loop-with-less-css/)

LESS loop to generate classes

class

CSS