scss-spacing-generator.scss

// programmatic generation of scss spacer classes to produce alike:
// .mt-1 { margin-top: 1rem; }

$spacings: (margin: m, padding: p);
$directions: (top: t, right: r, bottom: b, left: l);

@mixin makeSpacing($rems) {
  $sizing: 0;
  $remString: #{$rems};
  $splitStr: str-index($remString, '.');

  @if ($splitStr) {
    $front: str-slice($remString, $splitStr - str-length($remString) + 1, $splitStr - 1);
    $back: str-slice($remString, $splitStr + 1, -1);
    $sizing: $front + '-' + $back;
  } @else {
    $sizing: $remString;
  }
	
	@each $spc, $spc-a in $spacings {
		@each $dir, $dir-a in $directions {
			.#{$spc-a}#{$dir-a}-#{$sizing} {
				#{$spc}-#{$dir}: #{$rems}rem;
			}
		}
		.#{$spc-a}x-#{$sizing} {
			@extend .#{$spc-a}r-#{$sizing};
			@extend .#{$spc-a}l-#{$sizing};
		}
		.#{$spc-a}y-#{$sizing} {
			@extend .#{$spc-a}t-#{$sizing};
			@extend .#{$spc-a}b-#{$sizing};
		}
		.#{$spc-a}-#{$sizing} {
			@extend .#{$spc-a}x-#{$sizing};
			@extend .#{$spc-a}y-#{$sizing};
		}
	}
}

@include makeSpacing(0.5);
@include makeSpacing(1);
@include makeSpacing(1.5);
@include makeSpacing(2);
@include makeSpacing(2.5);

returns alike:

.mt-0-5, .my-0-5, .m-0-5 {
  margin-top: 0.5rem;
}

.mr-0-5, .mx-0-5, .m-0-5 {
  margin-right: 0.5rem;
}

.mb-0-5, .my-0-5, .m-0-5 {
  margin-bottom: 0.5rem;
}

.ml-0-5, .mx-0-5, .m-0-5 {
  margin-left: 0.5rem;
}

.pt-0-5, .py-0-5, .p-0-5 {
  padding-top: 0.5rem;
}