tabler.tabler/core/scss/mixins/_functions.scss

@function theme-color-lighter($color, $background: #fff) {
  @return mix($color, $background, 10%);
}

@function theme-color-darker($color) {
  @return shade-color($color, 10%);
}

//
// Replace all occurrences of a substring within a string.
//
@function str-replace($string, $search, $replace: "") {
  $index: str-index($string, $search);

  @if $index {
    @return str-slice($string, 1, $index - 1) + $replace + str-replace(str-slice($string, $index + str-length($search)), $search, $replace);
  }

  @return $string;
}

@mixin media-breakpoint-down-than($name, $breakpoints: $grid-breakpoints) {
  $prev: breakpoint-prev($name);

  @if $prev == null {
    @content;
  } @else {
    $max: breakpoint-max($prev, $breakpoints);

    @if $max {
      @media (max-width: $max) {
        @content;
      }
    } @else {
      @content;
    }
  }
}

@function breakpoint-prev($name, $breakpoints: $grid-breakpoints, $breakpoint-names: map-keys($breakpoints)) {
  $n: index($breakpoint-names, $name);
  @if not $n {
    @error "breakpoint `#{$name}` not found in `#{$breakpoints}`";
  }
  @return if($n > 1, nth($breakpoint-names, $n - 1), null);
}

//
// Escape SVG strings.
//
@function escape-svg($string) {
  @if str-index($string, "data:image/svg+xml") {
    @each $char, $encoded in $escaped-characters {
      // Do not escape the url brackets
      @if str-index($string, "url(") == 1 {
        $string: url("#{str-replace(str-slice($string, 6, -3), $char, $encoded)}");
      } @else {
        $string: str-replace($string, $char, $encoded);
      }
    }
  }

  @return $string;
}

/**
 * Converts a given value to a percentage string.
 *
 * @param {Number} $value - The value to be converted to a percentage.
 * @return {String} - The percentage representation of the value.
 */
@function to-percentage($value) {
  @return if(unitless($value), percentage($value), $value);
}

/**
 * Generates a transparent version of the given color.
 *
 * @param {Color} $color - The base color to be made transparent.
 * @param {Number} $alpha - The level of transparency, ranging from 0 (fully transparent) to 1 (fully opaque). Default is 1.
 * @return {Color} - The resulting color with the specified transparency.
 */
@function color-transparent($color, $alpha: 1, $background: transparent) {
  @if $alpha == 1 {
    @return $color;
  } @else {
    @return color-mix(in srgb, #{$color} #{to-percentage($alpha)}, $background);
  }
}

@function url-svg($svg) {
  $svg: str-replace($svg, '#', '%23');
  $svg: str-replace($svg, '<svg', '<svg xmlns="http://www.w3.org/2000/svg"');

  @return url('data:image/svg+xml;charset=UTF-8,#{$svg}');
}