@mixin selectors_appendToHostSelector($simpleSelectorModifier) {
	$finalSelectors: ();

	// loop over each compound selector (.foo .bar, .baz .bar = 2 compound selectors)
	@for $i from 1 through length(&) {
		// get the compounded selector
		$compoundSelector: nth(&, $i);
		// append the modifier and add the newly generated compound selector to the final list of selectors

		$replace: 1;

		@if nth($compoundSelector, 1) == ':global' {
			$replace: 2;
		}

		$finalSelectors: append($finalSelectors, set_nth($compoundSelector, $replace, nth($compoundSelector, 1) + $simpleSelectorModifier), comma);
	}

	// output css
	@at-root #{selector_parse($finalSelectors)} {
		@content;
	}
}

// this works its way up the dom tree $appendToParentN levels and appends itself
@mixin selectors_appendToNthParentSelector($simpleSelectorModifier, $appendToParentN: 1) {
	$finalSelectors: ();

	// loop over each compound selector (.foo .bar, .baz .bar = 2 compound selectors)
	@for $i from 1 through length(&) {
		// get the compounded selector
		$compoundSelector: nth(&, $i);
		// determine the simple selector (within the compound selector) to append the modifier to
		$appendToIndex: length($compoundSelector) - $appendToParentN;
		// append the modifier and add the newly generated compound selector to the final list of selectors
		$finalSelectors: append($finalSelectors, set_nth($compoundSelector, $appendToIndex, nth($compoundSelector, $appendToIndex) + $simpleSelectorModifier), comma);
	}
	// output css
	@at-root #{selector_parse($finalSelectors)} {
		@content;
	}
}

// does nothing more set the properties exactly as is but is helpful for consistent and easily readable definitions (especially indentation-based)
@mixin selectors_setAsDefaults() {
	@content;
}

// styles that only apply when the host has the given modifier selector
// note: this is the same as the 'selectors_ifHostStateIs' mixin but helps readability
@mixin selectors_ifHostHasModifier($hostStateSelector) {
	@include selectors_appendToHostSelector($hostStateSelector) {
		@content;
	}
}

// styles that only apply when the host has the given state selector
// note: this is the same as the 'selectors_ifHostHasModifier' mixin but helps readability
@mixin selectors_ifHostStateIs($hostStateSelector) {
	@include selectors_appendToHostSelector($hostStateSelector) {
		@content;
	}
}

@mixin selectors_parent {
	$parents: ();
	$parent: '';

	@each $selector in & {
		$length: length($selector);
		$index: 0;
		$last-selector: nth($selector, $length);

		@if ($length == 1) {
			@error "Used parent mixin on a top-level selector";
		}
		@else {
			$index: str-index($last-selector, '::');

			@if ($index) {
				$last-selector: str-slice($last-selector, 1, $index - 1);
			}
			@else {
				$last-selector: null;
			}
			// Inspect allows us to combine two selectors in one block.
			$parent: inspect(set-nth($selector, $length, #{$last-selector}));
			$parents: join($parents, $parent, comma);
		}
	}
	//@debug "selectors_parent: `#{$parents}`.";
	@at-root #{$parents} {
		@content;
	}
}