Adding is-bracketed() built-in function

Author: delapuente

src/context.cpp

@@ -810,6 +810,7 @@ namespace Sass {
     register_function(ctx, append_sig, append, env);
     register_function(ctx, zip_sig, zip, env);
     register_function(ctx, list_separator_sig, list_separator, env);
+    register_function(ctx, is_bracketed_sig, is_bracketed, env);
     // Map Functions
     register_function(ctx, map_get_sig, map_get, env);
     register_function(ctx, map_merge_sig, map_merge, env);

src/functions.cpp

@@ -1995,5 +1995,12 @@ namespace Sass {
       return SASS_MEMORY_NEW(String_Quoted, pstate, ss.str());
     }
 
+    Signature is_bracketed_sig = "is-bracketed($list)";
+    BUILT_IN(is_bracketed)
+    {
+      Value_Obj value = ARG("$list", Value);
+      List_Obj list = SASS_MEMORY_CAST(List, value);
+      return SASS_MEMORY_NEW(Boolean, pstate, list && list->is_bracketed());
+    }
   }
 }

src/functions.hpp

@@ -107,6 +107,7 @@ namespace Sass {
     extern Signature is_superselector_sig;
     extern Signature simple_selectors_sig;
     extern Signature selector_parse_sig;
+    extern Signature is_bracketed_sig;
 
     BUILT_IN(rgb);
     BUILT_IN(rgba_4);
@@ -189,6 +190,7 @@ namespace Sass {
     BUILT_IN(is_superselector);
     BUILT_IN(simple_selectors);
     BUILT_IN(selector_parse);
+    BUILT_IN(is_bracketed);
   }
 }