1 files changed, 45 insertions, 0 deletions
diff --git a/include/mbgl/style/expression/coalesce.hpp b/include/mbgl/style/expression/coalesce.hpp
new file mode 100644
index 0000000000..4e6a9b3793
--- /dev/null
+++ b/include/mbgl/style/expression/coalesce.hpp
@@ -0,0 +1,45 @@
+#pragma once
+
+#include <mbgl/style/expression/expression.hpp>
+#include <mbgl/style/conversion.hpp>
+#include <mbgl/style/expression/parsing_context.hpp>
+
+#include <memory>
+#include <map>
+
+namespace mbgl {
+namespace style {
+namespace expression {
+
+class Coalesce : public Expression {
+public:
+    using Args = std::vector<std::unique_ptr<Expression>>;
+    Coalesce(const type::Type& type_, Args args_) :
+        Expression(type_),
+        args(std::move(args_))
+    {}
+
+    static ParseResult parse(const mbgl::style::conversion::Convertible& value, ParsingContext& ctx);
+
+
+    EvaluationResult evaluate(const EvaluationContext& params) const override;
+    
+    void eachChild(const std::function<void(const Expression&)>& visit) const override;
+
+    bool operator==(const Expression& e) const override;
+    
+    std::size_t getLength() const {
+        return args.size();
+    }
+    
+    Expression* getChild(std::size_t i) const {
+        return args.at(i).get();
+    }
+    
+private:
+    Args args;
+};
+
+} // namespace expression
+} // namespace style
+} // namespace mbgl