jarv.is/assets/sass/abstracts/_functions.scss

@use "sass:math";
@use "sass:list";
@use "sass:string";

@use "settings";

// Gradient hack to get our custom underline to wrap:
// https://www.dannyguo.com/blog/animated-multiline-link-underlines-with-css/
@function underline-hack($color) {
  // [deprecated] Calculate lighter underline color compared to text
  // color by mix()'ing with background (#fff) to give the impression
  // of opacity but with MUCH better compatibility.
  // $color-opaque-hex: mix($color, $link-opacity-color, $link-underline-opacity);

  // Less compatible but better for light/dark mode switching.
  // We fall back to non-alpha hex colors with postcss-color-rgba-fallback to mitigate this.
  $color-opaque-alpha: rgba($color, math.div(settings.$link-underline-opacity, 100%));

  // Return non-gradient linear-gradient():
  @return linear-gradient($color-opaque-alpha, $color-opaque-alpha);
}

// Returns a list of strings from a given string separated by a given
// separator (defaults to comma).
// https://stackoverflow.com/a/65853667/1438024
@function str-split($str, $separator: ",") {
  // return immediately if this function isn't necessary
  @if (string.index("#{$str}", "#{$separator}") == null) {
    @return $str;
  }

  $str-list: ();

  @while string.index("#{$str}", "#{$separator}") != null {
    @if (string.index("#{$str}", "#{$separator}") > 1) {
      $str-list: list.append(
        $str-list,
        string.slice("#{$str}", 1, string.index("#{$str}", "#{$separator}") - 1)
      );
    }
    $str: string.slice(
      "#{$str}",
      string.index("#{$str}", "#{$separator}") + 1,
      string.length("#{$str}")
    );
  }

  @if (string.slice("#{$str}", 1, string.length("#{$str}")) != "") {
    $str-list: list.append($str-list, string.slice("#{$str}", 1, string.length("#{$str}")));
  }

  @return $str-list;
}