JavaScript `toString` and `parseInt` implementation in Sass.

SassMeister-input.scss

// ----
// Sass (v3.3.8)
// Compass (v1.0.0.alpha.19)
// ----

// JavaScript `toString` and `parseInt` implementation in Sass.

@function pow($num, $exp) {
  $result: 1;

  @if $exp > 0 {
    @for $i from 1 through $exp {
      $result: $result * $num;
    }
  }
  @else {
    @for $i from $exp to 0 {
      $result: $result / $num;
    }
  }

  @return $result;
}


@function charsFromBase($base: 10) {
  $chars:(
    // Binary
    2: '01',
    // Octal
    8: '01234567',
    // Decimal
    10: '0123456789',
    // Hexadecimal
    16: '0123456789abcdef',
    // Base 36
    36: '0123456789abcdefghijklmnopqrstuvwxyz',
    // Base 64
    64: 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
  );

  @if not map-has-key($chars, $base) {
    @warn "There is no base `#{$base}` available.";
  }
  @return map-get($chars, $base);
}

@function toString($num, $radix: 10) {
  $chars: charsFromBase($radix);
  $result: '';
  $sign: '';
  
  @if $num < 0 {
    $sign: '-';
    $num: abs($num);
  }
  
  @if $num >= 0 and $num < $radix {
    @return $sign + str-slice($chars, ($num + 1), ($num + 1));
  }
  
  $q: $num;
  @while $q != 0 {
    $r: $q % $radix;
    $q: floor($q / $radix);
    $result: str-slice($chars, ($r + 1), ($r + 1)) + $result;
  }
  
  @return $sign + $result;
}

@function parseInt($str, $radix: 10) {
  $chars: charsFromBase($radix);
  $result: 0;
  
  $is-negative: str-index($str, '-') == 1;
  
  @if $is-negative {
    $str: str-slice($str, 2);
  }
  
  @for $i from 1 through str-length($str) {
    $char: str-slice($str, -$i, -$i);
    $value: str-index($chars, $char) - 1;
    $result: $result + ($value * pow($radix, ($i - 1)));
  }
  
  @return if($is-negative, -$result, $result);
}


// Tests


test__binary {
  $fixture: (
    '-1': -1,
    '0': 0,
    '1': 1,
    '10': 2,
    '11': 3,
    '100': 4,
    '101': 5,
    '110': 6,
    '111': 7,
    '1000': 8,
    '1001': 9,
    '1010': 10,
    '11110010101111': 15535,
    '1001001000111100': 37436,
    '111001101101100001100100111001': 968235321
  );
  
  $test-parseInt: '';
  $test-toString: '';
  @each $str, $num in $fixture {
    $test-parseInt: $test-parseInt + if(parseInt($str, 2) == $num, '✔ ', 'X ');
    $test-toString: $test-toString + if(toString($num, 2) == $str, '✔ ', 'X ');
  }
  test-parseInt: $test-parseInt;
  test-toString: $test-toString;
}

test__hexadecimal {
  $fixture: (
    '-1': -1,
    '0': 0,
    '1': 1,
    '2': 2,
    '3': 3,
    '4': 4,
    '5': 5,
    '6': 6,
    '7': 7,
    '8': 8,
    '9': 9,
    'a': 10,
    '3caf': 15535,
    '923c': 37436,
    '39b61939': 968235321
  );
  
  $test-parseInt: '';
  $test-toString: '';
  @each $str, $num in $fixture {
    $test-parseInt: $test-parseInt + if(parseInt($str, 16) == $num, '✔ ', 'X ');
    $test-toString: $test-toString + if(toString($num, 16) == $str, '✔ ', 'X ');
  }
  test-parseInt: $test-parseInt;
  test-toString: $test-toString;
}

test__base36 {
  $fixture: (
    '-1': -1,
    '0': 0,
    '1': 1,
    '2': 2,
    '3': 3,
    '4': 4,
    '5': 5,
    '6': 6,
    '7': 7,
    '8': 8,
    '9': 9,
    'a': 10,
    'bzj': 15535,
    'svw': 37436,
    'g0gn5l': 968235321
  );
  
  $test-parseInt: '';
  $test-toString: '';
  @each $str, $num in $fixture {
    $test-parseInt: $test-parseInt + if(parseInt($str, 36) == $num, '✔ ', 'X ');
    $test-toString: $test-toString + if(toString($num, 36) == $str, '✔ ', 'X ');
  }
  test-parseInt: $test-parseInt;
  test-toString: $test-toString;
}

SassMeister-output.css

@charset "UTF-8";
test__binary {
  test-parseInt: "✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ";
  test-toString: "✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ";
}

test__hexadecimal {
  test-parseInt: "✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ";
  test-toString: "✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ";
}

test__base36 {
  test-parseInt: "✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ";
  test-toString: "✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ";
}