draconisplusplus/include/rfl/AnyOf.hpp

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2024-05-31 22:59:00 -04:00
#ifndef RFL_ANYOF_HPP_
#define RFL_ANYOF_HPP_
#include <string>
#include <utility>
#include <vector>
#include "Result.hpp"
#include "parsing/schema/ValidationType.hpp"
namespace rfl {
/// Requires that all of the contraints C and Cs be true.
template <class C, class... Cs>
struct AnyOf {
template <class T>
static rfl::Result<T> validate(const T& _value) noexcept {
return validate_impl<T, C, Cs...>(_value, {});
}
template <class T>
static parsing::schema::ValidationType to_schema() {
using ValidationType = parsing::schema::ValidationType;
const auto types = std::vector<ValidationType>(
{C::template to_schema<T>(), Cs::template to_schema<T>()...});
return ValidationType{ValidationType::AnyOf{.types_ = types}};
}
private:
static Error make_error_message(const std::vector<Error>& _errors) {
std::string msg =
"Expected at least one of the following validations to pass, but none "
"of them did:";
for (size_t i = 0; i < _errors.size(); ++i) {
msg += "\n" + std::to_string(i + 1) + ") " + _errors.at(i).what();
}
return Error(msg);
}
template <class T, class Head, class... Tail>
static rfl::Result<T> validate_impl(const T& _value,
std::vector<Error> _errors) {
const auto handle_err = [&](Error&& _err) {
_errors.push_back(std::forward<Error>(_err));
if constexpr (sizeof...(Tail) == 0) {
return make_error_message(_errors);
} else {
return validate_impl<T, Tail...>(
_value, std::forward<std::vector<Error>>(_errors));
}
};
return Head::validate(_value).or_else(handle_err);
}
};
} // namespace rfl
#endif