Initial commit

src/foundation/string.cppm

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+export module bedrock.foundation:string;
+
+import bedrock.numbers;
+import bedrock.semantics;
+import :byte;
+import :buffer;
+import :bytes_iterator;
+import :iterators.enumerate;
+import :iterators.reverse;
+
+namespace br {
+
+export class String final {
+   private:
+	BufferView m_data;
+
+	explicit String(BufferView&& view)
+		: m_data(view) {}
+
+   public:
+	friend class StringBuffer;
+
+	template <usize Size>
+	constexpr String(const char (&str)[Size])
+		: m_data(reinterpret_cast<const byte*>(&str), Size - 1) {}
+
+	[[nodiscard]]
+	auto byteSize() const noexcept -> usize {
+		return m_data.size();
+	}
+
+	[[nodiscard]]
+	auto characterLength() const noexcept -> usize {
+		usize nCharacters = 0;
+		for (auto byte : m_data) {
+			if ((byte & 0xc0_b) != 0x80_b) {
+				++nCharacters;
+			}
+		}
+		return nCharacters;
+	}
+
+	[[nodiscard]]
+	auto isEmpty() const noexcept -> bool {
+		return *this == "";
+	}
+
+	[[nodiscard]]
+	auto startsWith(const String& str) noexcept -> bool {
+		for (auto [byte, i] : str.bytes() | enumerate()) {
+			if (m_data[i] != byte) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	[[nodiscard]]
+	auto endsWith(const String& str) noexcept -> bool {
+		for (auto [byte, i] : str.bytes() | reverse() | enumerate()) {
+			if (m_data[i] != byte) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	// ====================================================================
+	// Implicit conversions
+	// ====================================================================
+	[[nodiscard]] operator BufferView() const noexcept {
+		return m_data;
+	}
+
+	[[nodiscard]]
+	auto bytes() const noexcept -> BytesIterator {
+		return m_data.bytes();
+	}
+
+	// ====================================================================
+	// Moveable
+	// ====================================================================
+	String(String&& other) noexcept
+		: m_data(move(other.m_data)) {}
+
+	auto operator=(String&& other) noexcept -> String& {
+		if (this == &other) {
+			m_data = move(other.m_data);
+		}
+		return *this;
+	}
+
+	~String() = default;
+
+	// ====================================================================
+	// Copyable
+	// ====================================================================
+	String(const String& other) = default;
+
+	auto operator=(const String& other) noexcept -> String& {
+		if (&other != this) {
+			m_data = other.m_data;
+		}
+		return *this;
+	}
+
+	// ====================================================================
+	// Equivalence
+	// ====================================================================
+	[[nodiscard]]
+	auto operator==(const String& other) const noexcept -> bool {
+		return m_data == other.m_data;
+	}
+
+	[[nodiscard]]
+	auto operator!=(const String& other) const noexcept -> bool {
+		return !(*this == other);
+	}
+};
+
+template <>
+struct EquivalenceType<String> {
+	static constexpr bool is_valid = true;
+};
+
+static_assert(Moveable<String>);
+static_assert(Copyable<String>);
+static_assert(Equivalence<String>);
+
+}  // namespace br