Deze verzameling functies is bedoeld om te testen of de waarde van een variabele van een bepaald type is. Is bijvoorbeeld 13remeen relatieve lengte? WAAR! Is "frosty the snowman"en geheel getal? ONWAAR!
Dit is waarschijnlijk het handigst voor makers van geavanceerde mixin en frameworks die hun code meer fouttolerant willen maken.
//// // A collection of function for advanced type checking // @author Hugo Giraudel //// @function is-number($value) ( @return type-of($value) == 'number'; ) @function is-time($value) ( @return is-number($value) and index('ms' 's', unit($value)) != null; ) @function is-duration($value) ( @return is-time($value); ) @function is-angle($value) ( @return is-number($value) and index('deg' 'rad' 'grad' 'turn', unit($value)) != null; ) @function is-frequency($value) ( @return is-number($value) and index('Hz' 'kHz', unit($value)) != null; ) @function is-integer($value) ( @return is-number($value) and round($value) == $value; ) @function is-relative-length($value) ( @return is-number($value) and index('em' 'ex' 'ch' 'rem' 'vw' 'vh' 'vmin' 'vmax', unit($value)) != null; ) @function is-absolute-length($value) ( @return is-number($value) and index('cm' 'mm' 'in' 'px' 'pt' 'pc', unit($value)) != null; ) @function is-percentage($value) ( @return is-number($value) and unit($value) == '%'; ) @function is-length($value) ( @return is-relative-length($value) or is-absolute-length($value); ) @function is-resolution($value) ( @return is-number($value) and index('dpi' 'dpcm' 'dppx', unit($value)) != null; ) @function is-position($value) ( @return is-length($value) or is-percentage($value) or index('top' 'right' 'bottom' 'left' 'center', $value) != null; )