1 files changed, 118 insertions, 0 deletions

diff --git a/src/bem/_suffix.scss b/src/bem/_suffix.scss
new file mode 100644
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+++ b/src/bem/_suffix.scss
@@ -0,0 +1,118 @@
+////
+/// @group BEM
+///
+/// @access public
+////
+
+/// 
+/// Generate a new suffix.
+///
+/// @param {string} $name - Suffix name
+///
+/// @content
+///
+/// @throw If the element is not preceded by a block or modifier.
+///
+/// @example scss - Using a suffix
+///   @include iro-bem-utility('hidden') {
+///     display: none;
+///     
+///     @media (max-width: 320px) {
+///       @include iro-bem-suffix('phone') {
+///         display: none;
+///       }
+///     }
+///     
+///     @media (max-width: 768px) {
+///       @include iro-bem-suffix('tablet') {
+///         display: none;
+///       }
+///     }
+///   }
+///   
+///   // Generates:
+///   
+///   .u-hidden {
+///     display: none;
+///   }
+///   
+///   @media (max-width: 320px) {
+///     .u-hidden@phone {
+///       display: none;
+///     }
+///   }
+///   
+///   @media (max-width: 768px) {
+///     .u-hidden@tablet {
+///       display: none;
+///     }
+///   }
+///
+@mixin iro-bem-suffix($name) {
+    $result:   iro-bem-suffix($name);
+    $selector: nth($result, 1);
+    $context:  nth($result, 2);
+
+    @include iro-bem-validate(
+        'suffix',
+        (name: $name),
+        $selector,
+        $context
+    );
+
+    @include iro-context-push($iro-bem-context-id, $context...);
+    @at-root #{$selector} {
+        @content;
+    }
+    @include iro-context-pop($iro-bem-context-id);
+}
+
+///
+/// Generate a new suffix. Check the respective mixin documentation for more information.
+/// 
+/// @return {list} A list with two items: 1. selector, 2. context or `null`
+///
+/// @see {mixin} iro-bem-suffix
+///
+@function iro-bem-suffix($name) {
+    //
+    // Suffixes can be used on block, element and modifier.
+    //
+
+    $noop: iro-context-assert-stack-count($iro-bem-context-id, $iro-bem-max-depth);
+    $noop: iro-context-assert-stack-must-contain($iro-bem-context-id, 'block');
+    $noop: iro-context-assert-stack-must-not-contain($iro-bem-context-id, 'suffix');
+
+    $parent-context:  iro-context-get($iro-bem-context-id, 'block' 'element' 'modifier');
+    $parent-selector: map-get(nth($parent-context, 2), 'selector');
+
+    @if not iro-selector-suffix-match(&, $parent-selector) {
+        //
+        // The current selector doesn't match the parent selector.
+        // The user manually added a selector between parent context and this suffix call.
+        // This case is forbidden because any outcome semantically wouldn't make sense:
+        //   - {b,e,m} [manual selector] {b,e,m}@suffix
+        //   - {b,e,m}@suffix [manual selector]
+        // The first case would make the modifier behave like an element.
+        // The second case is unintuitive, the code would be more clear by nesting the manual
+        // selector in the suffix instead.
+        //
+
+        @error 'A suffix must be an immediate child of the parent context';
+    }
+
+    //
+    // The suffix part can simply be appended.
+    // Possible outcomes:
+    //   - {b,e,m}@suffix
+    //
+
+    $selector: selector-append(&, $iro-bem-suffix-separator + $name);
+
+    $context: 'suffix', (
+        'name':     $name,
+        'selector': $selector
+    );
+
+    @return $selector $context;
+}