Bootstrap: extra framework grid generation

x-grid-framework.less

// Extra framework grid generation
//
// Based on bootstrap/grid-framework.less

.x-make-grid-columns(@columns: @grid-columns, @gutter-width: @grid-gutter-width, @prefix: ".col") {
    // Common styles for all sizes of grid columns, widths 1-12
    .x-col(@index) { // initial
        @item: ~"@{prefix}-xs-@{index}-of-@{columns}, @{prefix}-sm-@{index}-of-@{columns}, @{prefix}-md-@{index}-of-@{columns}, @{prefix}-lg-@{index}-of-@{columns}";
        .x-col((@index + 1), @item);
    }
    .x-col(@index, @list) when (@index =< @columns) { // general; "=<" isn't a typo
        @item: ~"@{prefix}-xs-@{index}-of-@{columns}, @{prefix}-sm-@{index}-of-@{columns}, @{prefix}-md-@{index}-of-@{columns}, @{prefix}-lg-@{index}-of-@{columns}";
        .x-col((@index + 1), ~"@{list}, @{item}");
    }
    .x-col(@index, @list) when (@index > @columns) { // terminal
        @{list} {
            position: relative;
            // Prevent columns from collapsing when empty
            min-height: 1px;
            // Inner gutter via padding
            padding-left:  ceil((@gutter-width / 2));
            padding-right: floor((@gutter-width / 2));
        }
    }
    .x-col(1); // kickstart it
}

.x-float-grid-columns(@class, @columns: @grid-columns, @gutter-width: @grid-gutter-width) {
    .x-col(@index) { // initial
        @item: ~".col-@{class}-@{index}-of-@{columns}";
        .x-col((@index + 1), @item);
    }
    .x-col(@index, @list) when (@index =< @columns) { // general
        @item: ~".col-@{class}-@{index}-of-@{columns}";
        .x-col((@index + 1), ~"@{list}, @{item}");
    }
    .x-col(@index, @list) when (@index > @columns) { // terminal
        @{list} {
            float: left;
        }
    }
    .x-col(1); // kickstart it
}

.x-calc-grid-column(@index, @class, @columns, @type) when (@type = width) and (@index > 0) {
    @item: ~".col-@{class}-@{index}-of-@{columns}";
    @{item} {
        width: percentage((@index / @grid-columns));
    }
}
.x-calc-grid-column(@index, @class, @columns, @type) when (@type = push) and (@index > 0) {
    @item: ~".col-@{class}-push-@{index}-of-@{columns}";
    @{item} {
        left: percentage((@index / @grid-columns));
    }
}
.x-calc-grid-column(@index, @class, @columns, @type) when (@type = push) and (@index = 0) {
    @item: ~".col-@{class}-push-0-of-@{columns}";
    @{item} {
        left: auto;
    }
}
.x-calc-grid-column(@index, @class, @columns, @type) when (@type = pull) and (@index > 0) {
    @item: ~".col-@{class}-pull-@{index}-of-@{columns}";
    @{item} {
        right: percentage((@index / @grid-columns));
    }
}
.x-calc-grid-column(@index, @class, @columns, @type) when (@type = pull) and (@index = 0) {
    @item: ~".col-@{class}-pull-0-of-@{columns}";
    @{item} {
        right: auto;
    }
}
.x-calc-grid-column(@index, @class, @columns, @type) when (@type = offset) {
    @item: ~".col-@{class}-offset-@{index}-of-@{columns}";
    @{item} {
        margin-left: percentage((@index / @grid-columns));
    }
}

// Basic looping in LESS
.x-loop-grid-columns(@index, @class, @columns, @type) when (@index >= 0) {
    .x-calc-grid-column(@index, @class, @columns, @type);
    // next iteration
    .x-loop-grid-columns((@index - 1), @class, @columns, @type);
}

// Create grid for specific class
.x-make-grid(@class, @columns: @grid-columns, @gutter-width: @grid-gutter-width) {
    .x-float-grid-columns(@class, @columns, @gutter-width);
    .x-loop-grid-columns(@columns, @class, @columns, width);
    .x-loop-grid-columns(@columns, @class, @columns, pull);
    .x-loop-grid-columns(@columns, @class, @columns, push);
    .x-loop-grid-columns(@columns, @class, @columns, offset);
}