93 lines
1.9 KiB
C++
93 lines
1.9 KiB
C++
#pragma once
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#include <cstddef>
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#include <variant>
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#include <list>
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#include <memory>
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#include <type_traits>
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namespace elna::source
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{
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/**
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* Position in the source text.
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*/
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struct position
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{
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/// Line.
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std::size_t line = 1;
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/// Column.
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std::size_t column = 1;
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};
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/**
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* A compilation error consists of an error message and position.
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*/
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class error
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{
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position m_position;
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protected:
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/**
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* \param position Error position in the source text.
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*/
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error(const position position);
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public:
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/// Error text.
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virtual std::string what() const = 0;
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/// Error line in the source text.
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std::size_t line() const noexcept;
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/// Error column in the source text.
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std::size_t column() const noexcept;
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};
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template<typename T>
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struct result
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{
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using E = std::list<std::unique_ptr<source::error>>;
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template<typename... Args, typename = std::enable_if<std::is_constructible_v<T, Args...>>>
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explicit result(Args&&... arguments)
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: payload(std::forward<Args>(arguments)...)
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{
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}
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explicit result(T&& result)
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: payload(std::move(result))
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{
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}
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template<typename U, typename = std::enable_if<std::is_base_of_v<error, U>>>
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explicit result(U&& first)
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{
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errors().emplace_back(std::make_unique<U>(first));
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}
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bool has_errors() const noexcept
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{
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return std::holds_alternative<E>(payload);
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}
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bool is_success() const noexcept
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{
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return std::holds_alternative<T>(payload);
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}
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T& success()
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{
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return std::get<T>(payload);
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}
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E& errors()
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{
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return std::get<E>(payload);
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}
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private:
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std::variant<T, E> payload;
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};
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}
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