WIP

4 files changed, 24 insertions, 1 deletions

diff --git a/include/mbgl/style/filter.hpp b/include/mbgl/style/filter.hpp
index a204a2b17a..31fef05a4a 100644
--- a/include/mbgl/style/filter.hpp
+++ b/include/mbgl/style/filter.hpp
@@ -3,6 +3,7 @@
 #include <mbgl/util/variant.hpp>
 #include <mbgl/util/feature.hpp>
 #include <mbgl/util/geometry.hpp>
+#include <mbgl/style/expression/expression.hpp>
 
 #include <string>
 #include <vector>
@@ -232,6 +233,15 @@ public:
         return true;
     }
 };
+    
+class ExpressionFilter {
+public:
+    std::shared_ptr<mbgl::style::expression::Expression> expression;
+    
+    friend bool operator==(const ExpressionFilter& lhs, const ExpressionFilter& rhs) {
+        return lhs.expression == rhs.expression;
+    }
+};
 
 
 using FilterBase = variant<
@@ -258,7 +268,8 @@ using FilterBase = variant<
     class IdentifierInFilter,
     class IdentifierNotInFilter,
     class HasIdentifierFilter,
-    class NotHasIdentifierFilter>;
+    class NotHasIdentifierFilter,
+    class ExpressionFilter>;
 
 class Filter : public FilterBase {
 public:
diff --git a/include/mbgl/style/filter_evaluator.hpp b/include/mbgl/style/filter_evaluator.hpp
index 66223d7282..bd63caa0a0 100644
--- a/include/mbgl/style/filter_evaluator.hpp
+++ b/include/mbgl/style/filter_evaluator.hpp
@@ -180,6 +180,10 @@ public:
     bool operator()(const NotHasIdentifierFilter&) const {
         return !featureIdentifier;
     }
+    
+    bool operator()(const ExpressionFilter&) const {
+        return false;
+    }
 
 private:
     template <class Op>
diff --git a/platform/darwin/src/NSPredicate+MGLAdditions.mm b/platform/darwin/src/NSPredicate+MGLAdditions.mm
index 3ffe200d01..1a643d41d0 100644
--- a/platform/darwin/src/NSPredicate+MGLAdditions.mm
+++ b/platform/darwin/src/NSPredicate+MGLAdditions.mm
@@ -194,6 +194,10 @@ public:
     NSPredicate *operator()(mbgl::style::NotHasIdentifierFilter filter) {
         return [NSPredicate predicateWithFormat:@"%K == nil", @"$id"];
     }
+    
+    NSPredicate *operator()(mbgl::style::ExpressionFilter filter) {
+        return nil;
+    }
 };
 
 @implementation NSPredicate (MGLAdditions)
diff --git a/src/mbgl/style/conversion/stringify.hpp b/src/mbgl/style/conversion/stringify.hpp
index 6ae6fede42..fd1af4ba0c 100644
--- a/src/mbgl/style/conversion/stringify.hpp
+++ b/src/mbgl/style/conversion/stringify.hpp
@@ -225,6 +225,10 @@ public:
     void operator()(const NotHasIdentifierFilter&) {
         stringifyUnaryFilter("!has", "$id");
     }
+    
+    void operator()(const ExpressionFilter&) {
+        stringifyUnaryFilter("herp", "derp");
+    }
 
 private:
     template <class F>