/*
  @a-pollo-doc
  @author: [Vittorio Vittori](http://github.com/vitto)
  @category: Functions
  @code: Usage example
    .selector {
      transition: color 0.25s ease('in-quad');
    }
  @css: CSS generated
    .selector {
      transition: color 0.25s cubic-bezier(0.55, 0.085, 0.68, 0.53);
    }
  @date: 2017-02-20T18:59:41+01:00
  @type: function
  @title: Easing transitions
  @name: ease
  @icon: fa fa-wheelchair-alt
  @param: {string} ($easing) [required]
          An easing name
  @public: true
  @returns: css
  @text: Returns a css `ease` effect for the css `transition` parameters, you have these effects:

    | Easing | Equivalent CSS easing |
    |-|-|
    | `in-back` | `cubic-bezier(0.6, -0.28, 0.735, 0.045)` |
    | `in-circ` | `cubic-bezier(0.6, 0.04, 0.98, 0.335)` |
    | `in-cubic` | `cubic-bezier(0.55, 0.055, 0.675, 0.19)` |
    | `in-expo` | `cubic-bezier(0.95, 0.05, 0.795, 0.035)` |
    | `in-out-back` | `cubic-bezier(0.68, -0.55, 0.265, 1.55)` |
    | `in-out-circ` | `cubic-bezier(0.785, 0.135, 0.15, 0.86)` |
    | `in-out-cubic` | `cubic-bezier(0.645, 0.045, 0.355, 1)` |
    | `in-out-expo` | `cubic-bezier(1, 0, 0, 1)` |
    | `in-out-quad` | `cubic-bezier(0.455, 0.03, 0.515, 0.955)` |
    | `in-out-quart` | `cubic-bezier(0.77, 0, 0.175, 1)` |
    | `in-out-quint` | `cubic-bezier(0.86, 0, 0.07, 1)` |
    | `in-out-sine` | `cubic-bezier(0.445, 0.05, 0.55, 0.95)` |
    | `in-quad` | `cubic-bezier(0.55, 0.085, 0.68, 0.53)` |
    | `in-quart` | `cubic-bezier(0.895, 0.03, 0.685, 0.22)` |
    | `in-quint` | `cubic-bezier(0.755, 0.05, 0.855, 0.06)` |
    | `in-sine` | `cubic-bezier(0.47, 0, 0.745, 0.715)` |
    | `out-back` | `cubic-bezier(0.175, 0.885, 0.32, 1.275)` |
    | `out-circ` | `cubic-bezier(0.075, 0.82, 0.165, 1)` |
    | `out-cubic` | `cubic-bezier(0.215, 0.61, 0.355, 1)` |
    | `out-expo` | `cubic-bezier(0.19, 1, 0.22, 1)` |
    | `out-quad` | `cubic-bezier(0.25, 0.46, 0.45, 0.94)` |
    | `out-quart` | `cubic-bezier(0.165, 0.84, 0.44, 1)` |
    | `out-quint` | `cubic-bezier(0.23, 1, 0.32, 1)` |
    | `out-sine` | `cubic-bezier(0.39, 0.575, 0.565, 1)` |
  @version: 4.0.0
*/

@function ease($easing) {
  $map: (
    'in-back': cubic-bezier(0.6, -0.28, 0.735, 0.045),
    'in-circ': cubic-bezier(0.6, 0.04, 0.98, 0.335),
    'in-cubic': cubic-bezier(0.55, 0.055, 0.675, 0.19),
    'in-expo': cubic-bezier(0.95, 0.05, 0.795, 0.035),
    'in-out-back': cubic-bezier(0.68, -0.55, 0.265, 1.55),
    'in-out-circ': cubic-bezier(0.785, 0.135, 0.15, 0.86),
    'in-out-cubic': cubic-bezier(0.645, 0.045, 0.355, 1),
    'in-out-expo': cubic-bezier(1, 0, 0, 1),
    'in-out-quad': cubic-bezier(0.455, 0.03, 0.515, 0.955),
    'in-out-quart': cubic-bezier(0.77, 0, 0.175, 1),
    'in-out-quint': cubic-bezier(0.86, 0, 0.07, 1),
    'in-out-sine': cubic-bezier(0.445, 0.05, 0.55, 0.95),
    'in-quad': cubic-bezier(0.55, 0.085, 0.68, 0.53),
    'in-quart': cubic-bezier(0.895, 0.03, 0.685, 0.22),
    'in-quint': cubic-bezier(0.755, 0.05, 0.855, 0.06),
    'in-sine': cubic-bezier(0.47, 0, 0.745, 0.715),
    'out-back': cubic-bezier(0.175, 0.885, 0.32, 1.275),
    'out-circ': cubic-bezier(0.075, 0.82, 0.165, 1),
    'out-cubic': cubic-bezier(0.215, 0.61, 0.355, 1),
    'out-expo': cubic-bezier(0.19, 1, 0.22, 1),
    'out-quad': cubic-bezier(0.25, 0.46, 0.45, 0.94),
    'out-quart': cubic-bezier(0.165, 0.84, 0.44, 1),
    'out-quint': cubic-bezier(0.23, 1, 0.32, 1),
    'out-sine': cubic-bezier(0.39, 0.575, 0.565, 1)
  );
  @return get($map, $easing);
}