SASS functions: merge-maps(), merge-lists(), get()

fn_map_list.scss

/// Merges maps or|and lists (optional).
///
/// @param {map | list} $map1 The first map
/// @param {map | list} $map2 The second map
/// @param {bool} $merge-lists Allow merge lists
/// @return {map | null} The new map or list or null at error
@function merge-maps($map1, $map2, $merge-lists: false) {
  @if (type-of($map1) == map or (type-of($map1) == list and length($map1) == 0)) and (type-of($map2) == map or (type-of($map2) == list and length($map2) == 0)) {
    $result: $map1;
    @each $key, $value in $map2 {
      @if (type-of(map-get($result, $key)) == map and type-of($value) == map) {
        $result: map-merge($result, ($key: recursive-map-merge(map-get($result, $key), $value)));
      }
      @else if ($merge-lists and type-of(map-get($result, $key)) == list and type-of($value) == list) {
        $result: map-merge($result, ($key: join(map-get($result, $key), $value)));
      }
      @else {
        $result: map-merge($result, ($key: $value));
      }
    }
    @return $result;
  }
  @warn "merge-maps() expects this parameters to be map types!";
  @return null;
}

/// Merges lists.
///
/// @param {list} $list The first map
/// @param {list} ...$lists The lists to merge
/// @return {list} The new list
@function merge-lists($list, $lists...) {
  $result: $list;
  @each $list in $lists {
    @each $value in $list {
      @if not index($result, $value) {
        $result: append($result, $value);
      }
    }
  }
  @return $result;
}

/// Gets map or list value by key.
///
/// @param {map} $map The source map
/// @param {string | number} $key The map key or list index
/// @return {mixed} The map value
@function get-value($map, $key) {
  @if (type-of($map) != map and type-of($map) != list) {
    @error "get-value(): invalid type of $map";
  }
  @if (type-of($key) != number or type-of($key) != string) {
    @error "get-value(): invalid type of $key";
  }
  @if map-has-key($map, $key) {
    @return map-get($map, $key);
  }
  @return map-get($map, quoted($key));
}

/// Returns color from map.
///
/// Example: `color: get-color("blue", "300"); background-color: get-color("green", 4);`
///
/// @param {string} $color Color name (`"red"`, `"gray"`)
/// @param {string | number} $index Color index (`"900"`, `900` or `9`)
/// @param {map} $color-maps Map of color maps
/// @return {color | null} Color or null
@function get-color($color, $index: "500", $maps: $color-maps) {
  @if type-of($index) != string {
    $index: quote(if ($index < 10, $index * 100, $index));
  }
  @return if (
      map-has-key($maps, $color, $index),
      map-get($maps, $color, $index),
      null
  );
}

/// Replaces or sets color and returns updated map.
///
/// Example: `$color-maps: set-color("green", "500", #0d9d1d);`
///
/// @param {string} $color Color name (`"red"`, `"green"`)
/// @param {string | number} $index Color index (`"900"`, `900` or `9`)
/// @param {color} $value New value (`#eee`, `#eeeeee` or `gray`)
/// @param {map} $maps Map of color maps
/// @return {map} New map
@function set-color($color, $index, $value, $maps: $color-maps) {
  @if type-of($index) != string {
    $index: quote(if ($index < 10, $index * 100, $index));
  }
  $map: map-merge(map-get($maps, $color), ($index: $value));
  @return map-merge($maps, ($color: $map));
}

/// Gets shade or tint color.
///
/// @param {color} $color Base color
/// @param {number} $percentage Shade or tint
/// @param {color} $color-contrast-light White color
/// @return {color}
///
@function calc-color($color, $percentage: 15%, $color-contrast-light: #fff) {
  @return if(
    color-contrast($color) == $color-contrast-light,
    shade-color($color, $percentage),
    tint-color($color, $percentage)
  );
}

/// Gets space size (padding or margin).
///
/// @param {int} $size the map key
/// @param {map} $spacers the map of element spaces
/// @return {string}
///
@function spacer($size: 2, $spacers: $spacers) {
  @return map-get($spacers, $size);
}