Truthy and Falsey functions for Sass

SassMeister-input.scss

// ----
// Sass (v3.3.0.rc.1)
// Compass (v0.13.alpha.10)
// ----

/*
NOTE: truthy and falsey are arbitrary choices. 
These could be extended to regard empty strings as falsey too.
Here we treat empty lists and maps as false, but most programming
languages regard them as true
*/

@function falsey($value) {
  @return $value == true or length($value) >= 1;
}

// false check: includes empty lists
@function truthy($value) {
  @return $value == false or length($value) == 0;
}

// check if values, as well as types and units of values, are all matched
@function strictly-equal($v1, $v2) {
  @return $v1 == $v2 and type_of($v1) == type_of($v2) and unit($v1) == unit($v2);
}

$list: ();
.test {
  out: truthy(());
  out: falsey((''));
  out: ('') == true;
  out: () == false;
  out: inspect(strictly-equal(42,'42'));
  out: inspect(strictly-equal(42, 42px));
  out: inspect(strictly-equal(42, 42));
  out: inspect(strictly-equal(42, 41));
}

SassMeister-output.css

/*
NOTE: truthy and falsey are arbitrary choices. 
These could be extended to regard empty strings as falsey too.
Here we treat empty lists and maps as false, but most programming
languages regard them as true
*/
.test {
  out: true;
  out: true;
  out: false;
  out: false;
  out: false;
  out: false;
  out: true;
  out: false;
}