1 files changed, 38 insertions, 0 deletions
diff --git a/include/mbgl/style/expression/at.hpp b/include/mbgl/style/expression/at.hpp
new file mode 100644
index 0000000000..e3eefa4fe8
--- /dev/null
+++ b/include/mbgl/style/expression/at.hpp
@@ -0,0 +1,38 @@
+#pragma once
+
+#include <mbgl/style/expression/expression.hpp>
+#include <mbgl/style/conversion.hpp>
+#include <memory>
+
+namespace mbgl {
+namespace style {
+namespace expression {
+
+class At : public Expression {
+public:
+    At(std::unique_ptr<Expression> index_, std::unique_ptr<Expression> input_) :
+        Expression(input_->getType().get<type::Array>().itemType),
+        index(std::move(index_)),
+        input(std::move(input_))
+    {}
+    
+    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&)>&) const override;
+
+    bool operator==(const Expression& e) const override {
+        if (auto rhs = dynamic_cast<const At*>(&e)) {
+            return *index == *(rhs->index) && *input == *(rhs->input);
+        }
+        return false;
+    }
+
+private:
+    std::unique_ptr<Expression> index;
+    std::unique_ptr<Expression> input;
+};
+
+} // namespace expression
+} // namespace style
+} // namespace mbgl