Simple sass animation mixins

mixins.animations.scss

@mixin animation($animate...) {
    $max: length($animate);
    $animations: '';

    @for $i from 1 through $max {
        $animations: #{$animations + nth($animate, $i)};

        @if $i < $max {
            $animations: #{$animations + ", "};
        }
    }

    -webkit-animation: $animations;
       -moz-animation: $animations;
        -ms-animation: $animations;
         -o-animation: $animations;
            animation: $animations;
}

@mixin keyframes($name) {
    @-webkit-keyframes #{$name} { @content; }
    @-moz-keyframes #{$name} { @content; }
    @-ms-keyframes #{$name} { @content; }
    @-o-keyframes #{$name} { @content; }
    @keyframes #{$name} { @content; }
}