1 files changed, 68 insertions, 0 deletions
diff --git a/include/mbgl/style/expression/comparison.hpp b/include/mbgl/style/expression/comparison.hpp
new file mode 100644
index 0000000000..cf64f5cd34
--- /dev/null
+++ b/include/mbgl/style/expression/comparison.hpp
@@ -0,0 +1,68 @@
+#pragma once
+
+#include <mbgl/style/expression/collator_expression.hpp>
+#include <mbgl/style/expression/expression.hpp>
+#include <mbgl/style/expression/parsing_context.hpp>
+#include <mbgl/style/conversion.hpp>
+
+#include <memory>
+
+namespace mbgl {
+namespace style {
+namespace expression {
+
+ParseResult parseComparison(const mbgl::style::conversion::Convertible&, ParsingContext&);
+
+class BasicComparison : public Expression {
+public:
+    using CompareFunctionType = bool (*) (Value, Value);
+
+    BasicComparison(
+        std::string op,
+        std::unique_ptr<Expression> lhs,
+        std::unique_ptr<Expression> rhs);
+
+    void eachChild(const std::function<void(const Expression&)>& visit) const override;
+    bool operator==(const Expression&) const override;
+    EvaluationResult evaluate(const EvaluationContext&) const override;
+    std::vector<optional<Value>> possibleOutputs() const override;
+    std::string getOperator() const override;
+
+private:
+    std::string op;
+    CompareFunctionType compare;
+    std::unique_ptr<Expression> lhs;
+    std::unique_ptr<Expression> rhs;
+    bool needsRuntimeTypeCheck;
+};
+
+class CollatorComparison : public Expression {
+public:
+    using CompareFunctionType = bool (*) (std::string, std::string, Collator);
+
+    CollatorComparison(
+        std::string op,
+        std::unique_ptr<Expression> lhs,
+        std::unique_ptr<Expression> rhs,
+        std::unique_ptr<Expression> collator);
+
+    void eachChild(const std::function<void(const Expression&)>& visit) const override;
+    bool operator==(const Expression&) const override;
+    EvaluationResult evaluate(const EvaluationContext&) const override;
+    std::vector<optional<Value>> possibleOutputs() const override;
+    std::string getOperator() const override;
+
+private:
+    std::string op;
+    CompareFunctionType compare;
+    std::unique_ptr<Expression> lhs;
+    std::unique_ptr<Expression> rhs;
+    std::unique_ptr<Expression> collator;
+    bool needsRuntimeTypeCheck;
+};
+
+
+
+} // namespace expression
+} // namespace style
+} // namespace mbgl