abc/assets/scss/foundation/_functions.scss

// Foundation by ZURB
// foundation.zurb.com
// Licensed under MIT Open Source

// This is the default html and body font-size for the base rem value.
$rem-base: 16px !default;

// IMPORT ONCE
// We use this to prevent styles from being loaded multiple times for compenents that rely on other components. 
$modules: () !default;
@mixin exports($name) {
  @if (index($modules, $name) == false) {
    $modules: append($modules, $name);
    @content;
  }
}

//
// @functions
//


// RANGES
// We use these functions to define ranges for various things, like media queries. 
@function lower-bound($range){
  @if length($range) <= 0 {
    @return 0;
  }
  @return nth($range,1);
}

@function upper-bound($range) {
  @if length($range) < 2 {
    @return 999999999999;
  }
  @return nth($range, 2);
}

// STRIP UNIT
// It strips the unit of measure and returns it
@function strip-unit($num) {
  @return $num / ($num * 0 + 1);
}

// CONVERT TO REM
@function convert-to-rem($value, $base-value: $rem-base)  {
  $value: strip-unit($value) / strip-unit($base-value) * 1rem;
  @if ($value == 0rem) { $value: 0; } // Turn 0rem into 0
  @return $value;
}

@function data($attr) {
  @if $namespace {
    @return '[data-' + $namespace + '-' + $attr + ']';
  }

  @return '[data-' + $attr + ']';
}

// REM CALC 

// New Syntax, allows to optionally calculate on a different base value to counter compounding effect of rem's.
// Call with 1, 2, 3 or 4 parameters, 'px' is not required but supported:
// 
//   rem-calc(10 20 30px 40);
// 
// Space delimited, if you want to delimit using comma's, wrap it in another pair of brackets
// 
//   rem-calc((10, 20, 30, 40px));
// 
// Optionally call with a different base (eg: 8px) to calculate rem.
// 
//   rem-calc(16px 32px 48px, 8px);
// 
// If you require to comma separate your list
// 
//   rem-calc((16px, 32px, 48), 8px);

@function rem-calc($values, $base-value: $rem-base) {
  $max: length($values);

  @if $max == 1 { @return convert-to-rem(nth($values, 1), $base-value); }

  $remValues: ();
  @for $i from 1 through $max {
    $remValues: append($remValues, convert-to-rem(nth($values, $i), $base-value));
  }
  @return $remValues;
}

// OLD EM CALC
// Deprecated: We'll drop support for this in 5.1.0, use rem-calc()
@function emCalc($values){
  @return rem-calc($values);
}

// OLD EM CALC
// Deprecated: We'll drop support for this in 5.1.0, use rem-calc()
@function em-calc($values){
  @return rem-calc($values);
}