1 files changed, 52 insertions, 0 deletions
diff --git a/include/mbgl/style/expression/format_expression.hpp b/include/mbgl/style/expression/format_expression.hpp
new file mode 100644
index 0000000000..b00674a88e
--- /dev/null
+++ b/include/mbgl/style/expression/format_expression.hpp
@@ -0,0 +1,52 @@
+#pragma once
+
+#include <mbgl/style/expression/expression.hpp>
+#include <mbgl/style/expression/formatted.hpp>
+#include <mbgl/style/expression/parsing_context.hpp>
+#include <mbgl/style/conversion.hpp>
+
+#include <memory>
+
+namespace mbgl {
+namespace style {
+namespace expression {
+
+struct FormatExpressionSection {
+    FormatExpressionSection(std::unique_ptr<Expression> text_,
+                            optional<std::unique_ptr<Expression>> fontScale_,
+                            optional<std::unique_ptr<Expression>> textFont_);
+    
+    std::shared_ptr<Expression> text;
+    optional<std::shared_ptr<Expression>> fontScale;
+    optional<std::shared_ptr<Expression>> textFont;
+};
+    
+class FormatExpression : public Expression {
+public:
+    FormatExpression(std::vector<FormatExpressionSection> sections);
+    
+    EvaluationResult evaluate(const EvaluationContext&) const override;
+    static ParseResult parse(const mbgl::style::conversion::Convertible&, ParsingContext&);
+    
+    void eachChild(const std::function<void(const Expression&)>&) const override;
+    
+    bool operator==(const Expression& e) const override;
+    
+    std::vector<optional<Value>> possibleOutputs() const override {
+        // Technically the combinatoric set of all children
+        // Usually, this.text will be undefined anyway
+        return { nullopt };
+    }
+    
+    mbgl::Value serialize() const override;
+    std::string getOperator() const override { return "format"; }
+private:
+    std::vector<FormatExpressionSection> sections;
+    std::unique_ptr<Expression> text;
+    optional<std::unique_ptr<Expression>> fontScale;
+    optional<std::unique_ptr<Expression>> textFont;
+};
+    
+} // namespace expression
+} // namespace style
+} // namespace mbgl