1 files changed, 94 insertions, 0 deletions
diff --git a/src/mbgl/style/conversion/constant.cpp b/src/mbgl/style/conversion/constant.cpp
new file mode 100644
index 0000000000..e837c4e70b
--- /dev/null
+++ b/src/mbgl/style/conversion/constant.cpp
@@ -0,0 +1,94 @@
+#include <mbgl/style/conversion/constant.hpp>
+
+namespace mbgl {
+namespace style {
+namespace conversion {
+
+optional<bool> Converter<bool>::operator()(const Convertible& value, Error& error) const {
+    optional<bool> converted = toBool(value);
+    if (!converted) {
+        error = { "value must be a boolean" };
+        return {};
+    }
+    return *converted;
+}
+
+optional<float> Converter<float>::operator()(const Convertible& value, Error& error) const {
+    optional<float> converted = toNumber(value);
+    if (!converted) {
+        error = { "value must be a number" };
+        return {};
+    }
+    return *converted;
+}
+
+optional<std::string> Converter<std::string>::operator()(const Convertible& value, Error& error) const {
+    optional<std::string> converted = toString(value);
+    if (!converted) {
+        error = { "value must be a string" };
+        return {};
+    }
+    return *converted;
+}
+
+optional<Color> Converter<Color>::operator()(const Convertible& value, Error& error) const {
+    optional<std::string> string = toString(value);
+    if (!string) {
+        error = { "value must be a string" };
+        return {};
+    }
+
+    optional<Color> color = Color::parse(*string);
+    if (!color) {
+        error = { "value must be a valid color" };
+        return {};
+    }
+
+    return *color;
+}
+
+optional<std::vector<float>> Converter<std::vector<float>>::operator()(const Convertible& value, Error& error) const {
+    if (!isArray(value)) {
+        error = { "value must be an array" };
+        return {};
+    }
+
+    std::vector<float> result;
+    result.reserve(arrayLength(value));
+
+    for (std::size_t i = 0; i < arrayLength(value); ++i) {
+        optional<float> number = toNumber(arrayMember(value, i));
+        if (!number) {
+            error = { "value must be an array of numbers" };
+            return {};
+        }
+        result.push_back(*number);
+    }
+
+    return result;
+}
+
+optional<std::vector<std::string>> Converter<std::vector<std::string>>::operator()(const Convertible& value, Error& error) const {
+    if (!isArray(value)) {
+        error = { "value must be an array" };
+        return {};
+    }
+
+    std::vector<std::string> result;
+    result.reserve(arrayLength(value));
+
+    for (std::size_t i = 0; i < arrayLength(value); ++i) {
+        optional<std::string> string = toString(arrayMember(value, i));
+        if (!string) {
+            error = { "value must be an array of strings" };
+            return {};
+        }
+        result.push_back(*string);
+    }
+
+    return result;
+}
+
+} // namespace conversion
+} // namespace style
+} // namespace mbgl