Relax typing for comparison operators

cmake/core-files.cmake

@@ -457,9 +457,9 @@ set(MBGL_CORE_FILES
     include/mbgl/style/expression/coercion.hpp
     include/mbgl/style/expression/collator.hpp
     include/mbgl/style/expression/collator_expression.hpp
+    include/mbgl/style/expression/comparison.hpp
     include/mbgl/style/expression/compound_expression.hpp
     include/mbgl/style/expression/dsl.hpp
-    include/mbgl/style/expression/equals.hpp
     include/mbgl/style/expression/error.hpp
     include/mbgl/style/expression/expression.hpp
     include/mbgl/style/expression/find_zoom_curve.hpp
@@ -485,9 +485,9 @@ set(MBGL_CORE_FILES
     src/mbgl/style/expression/coalesce.cpp
     src/mbgl/style/expression/coercion.cpp
     src/mbgl/style/expression/collator_expression.cpp
+    src/mbgl/style/expression/comparison.cpp
     src/mbgl/style/expression/compound_expression.cpp
     src/mbgl/style/expression/dsl.cpp
-    src/mbgl/style/expression/equals.cpp
     src/mbgl/style/expression/expression.cpp
     src/mbgl/style/expression/find_zoom_curve.cpp
     src/mbgl/style/expression/get_covering_stops.cpp

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

include/mbgl/style/expression/dsl.hpp

@@ -31,6 +31,7 @@ std::unique_ptr<Expression> literal(Value value);
 std::unique_ptr<Expression> literal(std::initializer_list<double> value);
 std::unique_ptr<Expression> literal(std::initializer_list<const char *> value);
 
+std::unique_ptr<Expression> assertion(type::Type, std::unique_ptr<Expression>);
 std::unique_ptr<Expression> number(std::unique_ptr<Expression>);
 std::unique_ptr<Expression> string(std::unique_ptr<Expression>);
 std::unique_ptr<Expression> boolean(std::unique_ptr<Expression>);

include/mbgl/style/expression/expression.hpp

@@ -133,7 +133,7 @@ enum class Kind : int32_t {
     Case,
     Any,
     All,
-    Equals,
+    Comparison,
 };
 
 class Expression {