Generated by SassMeister.com.

SassMeister-input-HTML.html

<div class="box"></div>

SassMeister-input.scss

// ----
// libsass (v3.2.5)
// ----

// Memoization
// didn't really try with multiple inputs ^^
@function memoize($getter, $inputs...) {
  $value: null;
  @if memoize-has($getter, $inputs) {
    $value: memoize-get($getter, $inputs);
  }
  @else {
    $value: memoize-set($getter, $inputs);
  }

  @return $value;
}
// "private" functions
@function memoize-has($getter, $inputs) {
  @return map-has-key($MEMOIZE__STORE, $getter)
      and map-has-key(map-get($MEMOIZE__STORE, $getter), '#{$inputs}');
}
@function memoize-get($getter, $inputs) {
  @return map-get(map-get($MEMOIZE__STORE, $getter), '#{$inputs}');
}
@function memoize-set($getter, $inputs) {
  $value: call($getter, $inputs...);
  $MEMOIZE__STORE: map-merge(
    $MEMOIZE__STORE,
    (
      $getter: map-merge(
        map-get($MEMOIZE__STORE, $getter) or (),
        ('#{$inputs}': $value)
      )
    )
  )!global;

  @return $value;
}
$MEMOIZE__STORE: ()!default;

/* fibonacci example */
$_fibonacci: 0;
@function _fibonacci($i) {
  // count each call
  $_fibonacci: $_fibonacci + 1!global;

  $i: round(abs($i));
  @if $i < 2 {
    @return $i;
  }
  @return fibonacci($i - 1) + fibonacci($i - 2);
}
@function fibonacci($i) {
  @return memoize('_fibonacci', $i);
}

memoized {
  /* res, exe */
  @for $i from 0 through 5 {
    φ: fibonacci($i), $_fibonacci;
  }
}

SassMeister-output.css

@charset "UTF-8";
/* fibonacci example */
memoized {
  /* res, exe */
  φ: 0, 1;
  φ: 1, 2;
  φ: 1, 3;
  φ: 2, 4;
  φ: 3, 5;
  φ: 5, 6;
}

SassMeister-rendered.html

<div class="box"></div>