Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.12)
// Compass (v1.0.3)
// ----

$border-types: (
  "#E4E2E0-alpha": ('1', '2'),
  "#CCC-bravo"   : ('1')
);

@mixin generate-borders($viewport: null, $borders: $border-types) {
  $_viewport:  if($viewport,  $viewport,  null);
  
  @each $color, $units in $borders {
    @each $unit in $units {
      $_unit:  '#{$unit}x';
      $_index: str-index($color, '-');
      $_color: str-slice($color, 1, $_index - 1);
      $_namespace: str-slice($color, $_index + 1, -1);
      
      @if($_viewport) {
        [data-#{$viewport}~="border--#{$namespace}__#{$_unit}-t"] {
          border-style: solid;
          border-color: #{$color};
          border-width: #{$unit}px 0 0;
        }
        [data-#{$viewport}~="border--#{$namespace}__#{$_unit}-b"] {
          border-style: solid;
          border-color: #{$color};
          border-width: 0 0 #{$unit}px;
        }
        [data-#{$viewport}~="border--#{$namespace}__#{$_unit}-l"] {
          border-style: solid;
          border-color: #{$color};
          border-width: 0 0 0 #{$unit}px;
        }
        [data-#{$viewport}~="border--#{$namespace}__#{$_unit}-r"] {
          border-style: solid;
          border-color: #{$color};
          border-width: 0 #{$unit}px 0 0;
        }
        [data-#{$viewport}~="border--#{$namespace}__#{$_unit}-e"] {
          border-style: solid;
          border-color: #{$color};
          border-width: #{$unit}px 0;
        }
        [data-#{$viewport}~="border--#{$namespace}__#{$_unit}-s"] {
          border-style: solid;
          border-color: #{$color};
          border-width: 0 #{$unit}px;
        }
      } @else {
        [class~="border--#{$_namespace}__#{$_unit}-t"] {
          border-style: solid;
          border-color: #{$_color};
          border-width: #{$unit}px 0 0;
        }
        [class~="border--#{$_namespace}__#{$_unit}-b"] {
          border-style: solid;
          border-color: #{$_color};
          border-width: 0 0 #{$unit}px;
        }
        [class~="border--#{$_namespace}__#{$_unit}-l"] {
          border-style: solid;
          border-color: #{$_color};
          border-width: 0 0 0 #{$unit}px;
        }
        [class~="border--#{$_namespace}__#{$_unit}-r"] {
          border-style: solid;
          border-color: #{$_color};
          border-width: 0 #{$unit}px 0 0;
        }
        [class~="border--#{$_namespace}__#{$_unit}-e"] {
          border-style: solid;
          border-color: #{$_color};
          border-width: #{$unit}px 0;
        }
        [class~="border--#{$_namespace}__#{$_unit}-s"] {
          border-style: solid;
          border-color: #{$_color};
          border-width: 0 #{$_unit}px;
        }
      }
      
    }
  }
}

@include generate-borders();

SassMeister-output.css

[class~="border--alpha__1x-t"] {
  border-style: solid;
  border-color: #E4E2E0;
  border-width: 1px 0 0;
}

[class~="border--alpha__1x-b"] {
  border-style: solid;
  border-color: #E4E2E0;
  border-width: 0 0 1px;
}

[class~="border--alpha__1x-l"] {
  border-style: solid;
  border-color: #E4E2E0;
  border-width: 0 0 0 1px;
}

[class~="border--alpha__1x-r"] {
  border-style: solid;
  border-color: #E4E2E0;
  border-width: 0 1px 0 0;
}

[class~="border--alpha__1x-e"] {
  border-style: solid;
  border-color: #E4E2E0;
  border-width: 1px 0;
}

[class~="border--alpha__1x-s"] {
  border-style: solid;
  border-color: #E4E2E0;
  border-width: 0 1xpx;
}

[class~="border--alpha__2x-t"] {
  border-style: solid;
  border-color: #E4E2E0;
  border-width: 2px 0 0;
}

[class~="border--alpha__2x-b"] {
  border-style: solid;
  border-color: #E4E2E0;
  border-width: 0 0 2px;
}

[class~="border--alpha__2x-l"] {
  border-style: solid;
  border-color: #E4E2E0;
  border-width: 0 0 0 2px;
}

[class~="border--alpha__2x-r"] {
  border-style: solid;
  border-color: #E4E2E0;
  border-width: 0 2px 0 0;
}

[class~="border--alpha__2x-e"] {
  border-style: solid;
  border-color: #E4E2E0;
  border-width: 2px 0;
}

[class~="border--alpha__2x-s"] {
  border-style: solid;
  border-color: #E4E2E0;
  border-width: 0 2xpx;
}

[class~="border--bravo__1x-t"] {
  border-style: solid;
  border-color: #CCC;
  border-width: 1px 0 0;
}

[class~="border--bravo__1x-b"] {
  border-style: solid;
  border-color: #CCC;
  border-width: 0 0 1px;
}

[class~="border--bravo__1x-l"] {
  border-style: solid;
  border-color: #CCC;
  border-width: 0 0 0 1px;
}

[class~="border--bravo__1x-r"] {
  border-style: solid;
  border-color: #CCC;
  border-width: 0 1px 0 0;
}

[class~="border--bravo__1x-e"] {
  border-style: solid;
  border-color: #CCC;
  border-width: 1px 0;
}

[class~="border--bravo__1x-s"] {
  border-style: solid;
  border-color: #CCC;
  border-width: 0 1xpx;
}