partial @at-root support (leafo#193)

Author: robocoder

src/Compiler.php

@@ -530,6 +530,36 @@ protected function mediaParent($scope)
         return $scope;
     }
 
+    /**
+     * Compile at-root
+     *
+     * @param \stdClass $block
+     */
+    protected function compileAtRoot($block)
+    {
+        $env = $this->pushEnv($block);
+
+        $envs = $this->compactEnv($env);
+
+        if (isset($block->with)) {
+            // @todo move outside of nested directives, e.g., (without: all), (without: media supports), (with: rule)
+        } else {
+            // exclude selectors by default
+            $this->env->parent = $this->rootEnv;
+        }
+
+        $this->scope = $this->makeOutputBlock('at-root');
+        $this->scope->depth = 1;
+        $this->scope->parent->children[] = $this->scope;
+
+        $this->compileChildren($block->children, $this->scope);
+
+        $this->scope = $this->scope->parent;
+        $this->env   = $this->extractEnv($envs);
+
+        $this->popEnv();
+    }
+
     /**
      * Compile keyframe block
      *
@@ -1084,6 +1114,10 @@ protected function compileChild($child, $out)
                 }
                 break;
 
+            case 'at-root':
+                $this->compileAtRoot($child[1]);
+                break;
+
             case 'media':
                 $this->compileMedia($child[1]);
                 break;

src/Parser.php

@@ -241,6 +241,20 @@ protected function parseChunk()
 
         // the directives
         if (isset($this->buffer[$this->count]) && $this->buffer[$this->count] === '@') {
+            if ($this->literal('@at-root') &&
+                ($this->selectors($selector) || true) &&
+                ($this->map($with) || true) &&
+                $this->literal('{')
+            ) {
+                $atRoot = $this->pushSpecialBlock('at-root', $s);
+                $atRoot->selector = $selector;
+                $atRoot->with = $with;
+
+                return true;
+            }
+
+            $this->seek($s);
+
             if ($this->literal('@media') && $this->mediaQueryList($mediaQueryList) && $this->literal('{')) {
                 $media = $this->pushSpecialBlock('media', $s);
                 $media->queryList = $mediaQueryList[2];
@@ -1393,7 +1407,9 @@ protected function map(&$out)
     {
         $s = $this->seek();
 
-        $this->literal('(');
+        if (! $this->literal('(')) {
+            return false;
+        }
 
         $keys = array();
         $values = array();

tests/inputs/at_root.scss

@@ -0,0 +1,24 @@
+.first {
+  color: red;
+}
+body{
+.second {
+  color: white;
+
+  @at-root {
+    .nested1 {
+      color: blue;
+      @at-root {
+        .nested2 {
+          color: yellow;
+        }
+      }
+      color: orange;
+    }
+  }
+  color: black;
+}
+}
+.third {
+  color: green;
+}

tests/outputs/at_root.css

@@ -0,0 +1,15 @@
+.first {
+  color: red; }
+
+body .second {
+  color: white;
+  color: black; }
+
+    .nested1 {
+      color: blue;
+      color: orange; }
+        .nested2 {
+          color: yellow; }
+
+.third {
+  color: green; }

tests/outputs_numbered/at_root.css

@@ -0,0 +1,19 @@
+/* line 1, inputs/at_root.scss */
+.first {
+  color: red; }
+/* line 4, inputs/at_root.scss */
+/* line 5, inputs/at_root.scss */
+  body .second {
+    color: white;
+    color: black; }
+
+/* line 9, inputs/at_root.scss */
+.nested1 {
+color: blue;
+color: orange; }
+/* line 12, inputs/at_root.scss */
+.nested2 {
+color: yellow; }
+/* line 22, inputs/at_root.scss */
+.third {
+  color: green; }