Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.2.19)
// Compass (v0.12.7)
// Sass List-Maps (v0.9.9)
// ----

@import "sass-list-maps";

@function is-list($value) {
  @return if(length($value) > 1, true, false);
}

@mixin cascade($selectors, $amount:300, $reverse:false) {
    
    $is-list: is-list($selectors);
    $length: if($is-list, length($selectors), $selectors);
    
    @for $i from 1 through $length {
      
        $index: if($reverse, $length + 1 - $i, $i);
        $delay: $i * $amount;
        
        @if $is-list {
          #{nth($selectors, $index)} {
            transition-delay: $delay + ms;
          }
        }
        @else {
          &:nth-of-type(#{$index}) {
            transition-delay: $delay + ms;
          } 
        }
    }
}

.block {
  @include cascade((".foo", ".bar", ".baz"), $reverse:true);
  @include cascade(3);
}

SassMeister-output.css

.block .baz {
  transition-delay: 300ms;
}
.block .bar {
  transition-delay: 600ms;
}
.block .foo {
  transition-delay: 900ms;
}
.block:nth-of-type(1) {
  transition-delay: 300ms;
}
.block:nth-of-type(2) {
  transition-delay: 600ms;
}
.block:nth-of-type(3) {
  transition-delay: 900ms;
}