1 files changed, 3 insertions, 156 deletions
diff --git a/src/mbgl/style/conversion/stringify.hpp b/src/mbgl/style/conversion/stringify.hpp
index 7b7727d7c4..74171763a0 100644
--- a/src/mbgl/style/conversion/stringify.hpp
+++ b/src/mbgl/style/conversion/stringify.hpp
@@ -126,162 +126,9 @@ void stringify(Writer& writer, const FeatureIdentifier& id) {
 }
 
 template <class Writer>
-class StringifyFilter {
-public:
-    Writer& writer;
-
-    void operator()(const NullFilter&) {
-        writer.Null();
-    }
-
-    void operator()(const EqualsFilter& f) {
-        stringifyBinaryFilter(f, "==");
-    }
-
-    void operator()(const NotEqualsFilter& f) {
-        stringifyBinaryFilter(f, "!=");
-    }
-
-    void operator()(const LessThanFilter& f) {
-        stringifyBinaryFilter(f, "<");
-    }
-
-    void operator()(const LessThanEqualsFilter& f) {
-        stringifyBinaryFilter(f, "<=");
-    }
-
-    void operator()(const GreaterThanFilter& f) {
-        stringifyBinaryFilter(f, ">");
-    }
-
-    void operator()(const GreaterThanEqualsFilter& f) {
-        stringifyBinaryFilter(f, ">=");
-    }
-
-    void operator()(const InFilter& f) {
-        stringifySetFilter(f, "in");
-    }
-
-    void operator()(const NotInFilter& f) {
-        stringifySetFilter(f, "!in");
-    }
-
-    void operator()(const AllFilter& f) {
-        stringifyCompoundFilter(f, "all");
-    }
-
-    void operator()(const AnyFilter& f) {
-        stringifyCompoundFilter(f, "any");
-    }
-
-    void operator()(const NoneFilter& f) {
-        stringifyCompoundFilter(f, "none");
-    }
-
-    void operator()(const HasFilter& f) {
-        stringifyUnaryFilter("has", f.key);
-    }
-
-    void operator()(const NotHasFilter& f) {
-        stringifyUnaryFilter("!has", f.key);
-    }
-
-    void operator()(const TypeEqualsFilter& f) {
-        stringifyBinaryFilter(f, "==", "$type");
-    }
-
-    void operator()(const TypeNotEqualsFilter& f) {
-        stringifyBinaryFilter(f, "!=", "$type");
-    }
-
-    void operator()(const TypeInFilter& f) {
-        stringifySetFilter(f, "in", "$type");
-    }
-
-    void operator()(const TypeNotInFilter& f) {
-        stringifySetFilter(f, "!in", "$type");
-    }
-
-    void operator()(const IdentifierEqualsFilter& f) {
-        stringifyBinaryFilter(f, "==", "$id");
-    }
-
-    void operator()(const IdentifierNotEqualsFilter& f) {
-        stringifyBinaryFilter(f, "!=", "$id");
-    }
-
-    void operator()(const IdentifierInFilter& f) {
-        stringifySetFilter(f, "in", "$id");
-    }
-
-    void operator()(const IdentifierNotInFilter& f) {
-        stringifySetFilter(f, "!in", "$id");
-    }
-
-    void operator()(const HasIdentifierFilter&) {
-        stringifyUnaryFilter("has", "$id");
-    }
-
-    void operator()(const NotHasIdentifierFilter&) {
-        stringifyUnaryFilter("!has", "$id");
-    }
-    
-    void operator()(const ExpressionFilter& filter) {
-        stringify(writer, filter.expression->serialize());
-    }
-
-private:
-    template <class F>
-    void stringifyBinaryFilter(const F& f, const char * op) {
-        stringifyBinaryFilter(f, op, f.key);
-    }
-
-    template <class F>
-    void stringifyBinaryFilter(const F& f, const char * op, const std::string& key) {
-        writer.StartArray();
-        writer.String(op);
-        writer.String(key);
-        stringify(writer, f.value);
-        writer.EndArray();
-    }
-
-    template <class F>
-    void stringifySetFilter(const F& f, const char * op) {
-        stringifySetFilter(f, op, f.key);
-    }
-
-    template <class F>
-    void stringifySetFilter(const F& f, const char * op, const std::string& key) {
-        writer.StartArray();
-        writer.String(op);
-        writer.String(key);
-        for (const auto& value : f.values) {
-            stringify(writer, value);
-        }
-        writer.EndArray();
-    }
-
-    template <class F>
-    void stringifyCompoundFilter(const F& f, const char * op) {
-        writer.StartArray();
-        writer.String(op);
-        for (const auto& filter : f.filters) {
-            Filter::visit(filter, *this);
-        }
-        writer.EndArray();
-    }
-
-    void stringifyUnaryFilter(const char * op, const std::string& key) {
-        writer.StartArray();
-        writer.String(op);
-        writer.String(key);
-        writer.EndArray();
-    }
-};
-
-template <class Writer>
-void stringify(Writer& writer, const Filter& f) {
-    Filter::visit(f, StringifyFilter<Writer> { writer });
+void stringify(Writer& writer, const Filter& filter) {
+    if (!filter.expression) writer.Null();
+    else stringify(writer, (*filter.expression)->serialize());
 }
 
 template <class Writer>