Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.0.rc.1)
// Compass (v0.13.alpha.10)
// ----

$store: ();

@function store-get($key) {
    @each $item in $store {
        @if nth($item, 1) == $key {
            @return nth($item, 2);
        }
    }
    
    @return null;
}

@function store-index($key) {
    $index: false;
    
    @for $i from 1 through length($store) {
        @if nth(nth($store, $i), 1) == $key {
            $index: $i;
        }
    }
    
    @return $index;
}

@function store-set($key, $value) {
    $index: store-index($key);
    
    @if $index {
        $result: ();
        
        @for $i from 1 through length($store) {
            @if $i == $index {
                $result: append($result, ( $key $value ), comma);
            } @else {
                $result: append($result, nth($store, $i), comma);
            }
        }
        
        $store: $result;
    } @else {
        $store: append( $store, ($key $value), comma );
    }
    
    @return true;
}

TEST {
    before: store-get(test);
    create: store-set(test, create);
    after:  store-get(test);
    update: store-set(test, update);
    final:  store-get(test);
    store:  $store;
}

SassMeister-output.css

TEST {
  create: true;
  after: create;
  update: true;
  final: update;
  store: test update;
}