1 files changed, 342 insertions, 0 deletions
diff --git a/nihil.ucl/array.ccm b/nihil.ucl/array.ccm
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+++ b/nihil.ucl/array.ccm
@@ -0,0 +1,342 @@
+/*
+ * This source code is released into the public domain.
+ */
+
+module;
+
+#include <cassert>
+#include <cstdint>
+#include <cstdlib>
+#include <string>
+
+#include <ucl.h>
+
+export module nihil.ucl:array;
+
+import :object;
+
+namespace nihil::ucl {
+
+export template<datatype T>
+struct array;
+
+template<datatype T>
+struct array_iterator {
+	using difference_type = std::ptrdiff_t;
+	using value_type = T;
+	using reference = T&;
+	using pointer = T*;
+
+	array_iterator() = default;
+
+	auto operator* (this array_iterator const &self) -> T
+	{
+		auto uobj = ::ucl_array_find_index(self._array, self._idx);
+		if (uobj == nullptr)
+			throw error("failed to fetch UCL array index");
+
+		return T(::ucl_object_ref(uobj));
+	}
+
+	auto operator[] (this array_iterator const &self,
+			 difference_type idx)
+		-> T
+	{
+		return *(self + idx);
+	}
+
+	auto operator++ (this array_iterator &self) -> array_iterator&
+	{
+		++self._idx;
+		return self;
+	}
+
+	auto operator++ (this array_iterator &self, int) -> array_iterator
+	{
+		auto copy = self;
+		++self;
+		return copy;
+	}
+
+	auto operator-- (this array_iterator &self) -> array_iterator&
+	{
+		if (self._idx == 0)
+			throw std::out_of_range("attempt to iterate before "
+						"start of UCL array");
+		--self._idx;
+		return self;
+	}
+
+	auto operator-- (this array_iterator &self, int) -> array_iterator
+	{
+		auto copy = self;
+		--self;
+		return copy;
+	}
+
+	auto operator== (this array_iterator const &lhs,
+			 array_iterator const &rhs)
+		-> bool
+	{
+		return lhs._idx == rhs._idx;
+	}
+
+	auto operator<=> (this array_iterator const &lhs,
+			 array_iterator const &rhs)
+	{
+		return lhs._idx <=> rhs._idx;
+	}
+
+	auto operator+= (this array_iterator &lhs,
+			 difference_type rhs)
+		-> array_iterator &
+	{
+		lhs._idx += rhs;
+		return lhs;
+	}
+
+	auto operator-= (this array_iterator &lhs,
+			 difference_type rhs)
+		-> array_iterator &
+	{
+		lhs._idx -= rhs;
+		return lhs;
+	}
+
+	auto operator- (this array_iterator const &lhs,
+			array_iterator const &rhs)
+		-> difference_type
+	{
+		return lhs._idx - rhs._idx;
+	}
+
+private:
+	friend struct array<T>;
+
+	::ucl_object_t const *_array{};
+	std::size_t _idx{};
+
+	array_iterator(::ucl_object_t const *array, std::size_t idx)
+		: _array(array)
+		, _idx(idx)
+	{}
+};
+
+export template<datatype T>
+auto operator+(array_iterator<T> const &lhs,
+	       typename array_iterator<T>::difference_type rhs)
+	-> array_iterator<T>
+{
+	auto copy = lhs;
+	copy += rhs;
+	return copy;
+}
+
+export template<datatype T>
+auto operator+(typename array_iterator<T>::difference_type lhs,
+	       array_iterator<T> const &rhs)
+	-> array_iterator<T>
+{
+	return rhs - lhs;
+}
+
+export template<datatype T>
+auto operator-(array_iterator<T> const &lhs,
+	       typename array_iterator<T>::difference_type rhs)
+	-> array_iterator<T>
+{
+	auto copy = lhs;
+	copy -= rhs;
+	return copy;
+}
+
+static_assert(std::random_access_iterator<array_iterator<object>>);
+
+export template<datatype T>
+struct array final : object {
+	inline static constexpr object_type ucl_type = object_type::array;
+
+	using value_type = T;
+	using size_type = std::size_t;
+	using difference_type = std::ptrdiff_t;
+
+	array() : object(::ucl_object_typed_new(UCL_ARRAY))
+	{
+		if (_object == nullptr)
+			throw error("failed to create UCL object");
+	}
+
+	explicit array(::ucl_object_t *uobj) : object(uobj)
+	{
+		assert(type() == object_type::array);
+	}
+
+	/*
+	 * Create an array from an iterator pair.
+	 */
+	template<std::input_iterator Iterator>
+	requires(std::convertible_to<std::iter_value_t<Iterator>, T>)
+	array(Iterator first, Iterator last)
+		 : object(::ucl_object_typed_new(UCL_ARRAY))
+	{
+		if (_object == nullptr)
+			throw error("failed to create UCL object");
+
+		// This is exception safe, because if we throw here the
+		// base class destructor will free the array.
+		while (first != last) {
+			push_back(*first);
+			++first;
+		}
+	}
+
+	/*
+	 * Create an array from a range.
+	 */
+	template<std::ranges::range Range>
+	requires(std::convertible_to<std::ranges::range_value_t<Range>, T>)
+	array(std::from_range_t, Range &&range)
+		 : array(std::ranges::begin(range),
+			 std::ranges::end(range))
+	{
+	}
+
+	/*
+	 * Create an array from an initializer_list.
+	 */
+	array(std::initializer_list<T> const &list)
+		 : array(std::ranges::begin(list),
+			 std::ranges::end(list))
+	{
+	}
+
+	/*
+	 * Array iterator access.
+	 */
+
+	auto begin(this array const &self) -> array_iterator<T>
+	{
+		return {self.get_ucl_object(), 0};
+	}
+
+	auto end(this array const &self) -> array_iterator<T>
+	{
+		return {self.get_ucl_object(), self.size()};
+	}
+
+	/*
+	 * Return the size of this array.
+	 */
+	auto size(this array const &self) -> size_type
+	{
+		return ::ucl_array_size(self.get_ucl_object());
+	}
+
+	/*
+	 * Test if this array is empty.
+	 */
+	auto empty(this array const &self) -> bool
+	{
+		return self.size() == 0;
+	}
+
+	/*
+	 * Reserve space for future insertions.
+	 */
+	auto reserve(this array &self, size_type nelems) -> void
+	{
+		::ucl_object_reserve(self.get_ucl_object(), nelems);
+	}
+
+	/*
+	 * Append an element to the array.
+	 */
+	auto push_back(this array &self, value_type &&v) -> void
+	{
+		// There's no real benefit to moving the object here, but
+		// move it anyway to preserve the expected semantics.
+		auto copy = std::move(v);
+		self.push_back(copy);
+	}
+
+	auto push_back(this array &self, value_type const &v) -> void
+	{
+		auto uobj = ::ucl_object_ref(v.get_ucl_object());
+		::ucl_array_append(self.get_ucl_object(), uobj);
+	}
+
+	/*
+	 * Prepend an element to the array.
+	 */
+	auto push_front(this array &self, value_type &&v) -> void
+	{
+		// There's no real benefit to moving the object here, but
+		// move it anyway to preserve the expected semantics.
+		auto copy = std::move(v);
+		self.push_front(copy);
+	}
+
+	auto push_front(this array &self, value_type const &v) -> void
+	{
+		auto uobj = ::ucl_object_ref(v.get_ucl_object());
+		::ucl_array_prepend(self.get_ucl_object(), uobj);
+	}
+
+	/*
+	 * Access an array element by index.
+	 */
+	auto at(this array const &self, size_type idx) -> T
+	{
+		if (idx >= self.size())
+			throw std::out_of_range("UCL array index out of range");
+
+		auto uobj = ::ucl_array_find_index(self.get_ucl_object(), idx);
+		if (uobj == nullptr)
+			throw error("failed to fetch UCL array index");
+
+		return T(::ucl_object_ref(uobj));
+	}
+
+	auto operator[] (this array const &self, size_type idx) -> T
+	{
+		return self.at(idx);
+	}
+
+	/*
+	 * Return the first element.
+	 */
+	auto front(this array const &self) -> T
+	{
+		return self.at(0);
+	}
+
+	/*
+	 * Return the last element.
+	 */
+	auto back(this array const &self) -> T
+	{
+		if (self.empty())
+			throw std::out_of_range("attempt to access back() on "
+						"empty UCL array");
+		return self.at(self.size() - 1);
+	}
+};
+
+/*
+ * Comparison operators.
+ */
+
+export template<datatype T>
+auto operator==(array<T> const &a, array<T> const &b) -> bool
+{
+	if (a.size() != b.size())
+		return false;
+
+	for (typename array<T>::size_type i = 0; i < a.size(); ++i)
+		if (a.at(i) != b.at(i))
+			return false;
+
+	return true;
+}
+
+} // namespace nihil::ucl