Initial commit

core-library/views/trim-view.h

@@ -0,0 +1,53 @@
+#pragma once
+#include "core-library/views/view-closure.h"
+
+#include <ranges>
+
+namespace core {
+
+template<std::ranges::forward_range Range>
+	requires requires(Range&& range) {
+		*std::begin(range) == ' '; // Comparable with char literals.
+	}
+class trim_view : public std::ranges::view_interface<trim_view<Range>>
+{
+public:
+	constexpr explicit trim_view(Range range)
+	: m_range(std::move(range))
+	{
+	}
+
+	static constexpr bool is_space(auto&& c)
+	{
+		return c == ' ' || c == '\t' || c == '\r' || c == '\n' || c == '\0';
+	}
+
+	constexpr auto begin()
+	{
+		auto it = std::begin(m_range);
+		while (it != std::end(m_range) && is_space(*it))
+			++it;
+
+		return it;
+	}
+
+	constexpr auto end()
+	{
+		auto nonspace_end = std::end(m_range);
+
+		for (auto it = std::begin(m_range); it != std::end(m_range);)
+		{
+			if (!is_space(*it++))
+				nonspace_end = it;
+		}
+
+		return nonspace_end;
+	}
+
+private:
+	Range m_range{};
+};
+
+constexpr view_closure<trim_view> trim{};
+
+}