Map helper functions for Sass 3.3 and up
CSS Ruby
Latest commit 36008c5 Nov 12, 2014 @Snugug Snugug Create LICENSE
Resolves #8

Sassy Maps Gem Version Build Status

Sassy Maps adds a variety of functions aimed at helping you work with Sass 3.3 maps much easier.

Table of Contents

  1. Requirements
  2. Installation
  3. Using Sassy Maps
  4. Functions
  5. Optional Modules


Sassy Maps is a Sass extension, so you're going to need Sass installed. If you do not already have Sass installed, please read Install Sass. Sassy Maps 0.3.x requires Sass 3.3.0 or higher.

It is HIGHLY RECOMMENDED that you run all Sass (or Compass if using it) commands through Bundler

If the compiler you are using is not compatible with the above minimum versions, it will not compile correctly.

BE AWARE that CodeKit and most other GUI compilers do not support Bundler and are therefore NOT RECOMMENDED


The preferred way to install and use Sassy Maps is through Bundler. To do so, add the following to your Gemfile (Sass provided to ensure the correct versions are used):

gem "sass", "~>3.3.0"
gem "sassy-maps", "~>0.3.2"

Once you have done so, run bundle install to install your dependencies, and remember to run all of your compilation through bundle exec.

You can also install Sassy Maps through Bower as it has no Ruby requirements. To do so, run the following command:

bower install sassy-maps --save-dev

BE AWARE that while you can install Sassy Maps through Bower, Sassy Maps still only works with Sass compilers that have full compatibility with Sass 3.3.x and greater. If using Compass, you are also going to need to add the folder using Compass's add_import_path config option instead of the standard require.

Using Sassy Maps

If you already have a project made and you'd like to use Sassy Maps with it, add the following to your config.rb file:

require 'sassy-maps'

Then, add the following to your Sass file towards the top:

@import "sassy-maps";


  • map-get-deep($map, $keys...) - Returns the value of the final item in $keys from the map $map. Will return null if no value is present and will warn of errors in search (such as if an intermediate depth is null or not a map).
  • map-set($map, $key, $value) - Returns a map that has the $key in $map set to the to given $value.
  • map-set-deep($map, $keys, $value) - Returns a map that has the $key in $map set to the given $value. $key should be single-depth list of keys, for instance map-set-deep($map, ('foo' 'bar' 'baz'), "Hello World").
  • map-to-string($map) - Returns a string representation of the given $map.

Optional Modules

Sassy Maps comes with optional modules that extend upon the base functionality of Sassy Maps to provide additional map-based functionality. The following are optional modules available with Sassy Maps:


Memo is a Memoization framework for Sass. Designed with framework developers in mind, it makes it easy to store and retrieve the output of functions quickly and easily without needing to run the function again. For complex functions this should greatly speed up overall compilation time for repeat function calls with identical input.

To use Memo, simply include @import "memo"; and you're good to go (normal Sassy Maps installation still applies). Memo comes with two functions:

  • memo-set($module, $key, $value) - Sets a memoization $key to the given $value for the prescribed $module (framework). The function will return true. Also available as a mixin (@include memo-set($module, $key, $value)).
  • memo-get($module, $key) - Returns the value of the memoization $key for the prescribed $module.

Using Memo is fairly simple, just check to see if there is a memoization value for your key (and it's not null); if there is, return that, if not, run through the function, set the memoization, and return that result. The following example stores whether Memo is available in a variable and uses the function name as the memoization module, but if building a framework such as Breakpoint, that framework should be the name of the memoization module.

$Memo-Exists: function-exists(memo-get) and function-exists(memo-set);

@function percentage($target, $context) {
  @if $Memo-Exists {
    $result: memo-get(percentage, $target $context);

    @if $result != null {
      @return $result;

  $result: $target / $context * 100%;

  @if $Memo-Exists {
    $holder: memo-set(percentage, $target $context, $result);

  @return $result;

$half: percentage(20px, 40px); // No memoization exists, will run through the function
$half-again: percentage(20px, 40px); // Memoization exists, will just return that result