add csv-parser example

example/csv/main.cpp

@@ -0,0 +1,137 @@
+/*=============================================================================
+  Copyright (c) 2011-2016 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+
+#include <sprout/workaround/std/cstddef.hpp>
+#include <sprout/array.hpp>
+#include <sprout/sub_array.hpp>
+#include <sprout/range.hpp>
+#include <sprout/iterator.hpp>
+#include <sprout/memory.hpp>
+#include <sprout/string.hpp>
+#include <sprout/algorithm.hpp>
+
+template<typename T, std::size_t N>
+using subbed_array = sprout::sub_array<sprout::array<T, N> >;
+
+template<typename Char>
+struct csv_parser_settings {
+public:
+	typedef Char value_type;
+private:
+	value_type delim_;
+	value_type quote_;
+	value_type escape_;
+public:
+	constexpr csv_parser_settings(value_type delim = Char(','), value_type quote = Char('\"'))
+		: delim_(delim), quote_(quote), escape_(quote)
+	{}
+	constexpr csv_parser_settings(value_type delim, value_type quote, value_type escape)
+		: delim_(delim), quote_(quote), escape_(escape)
+	{}
+	constexpr value_type delimiter() const {
+		return delim_;
+	}
+	constexpr value_type quote() const {
+		return quote_;
+	}
+	constexpr value_type escape() const {
+		return escape_;
+	}
+};
+
+template<std::size_t N, std::size_t L, typename String, typename ResultString = String>
+constexpr subbed_array<subbed_array<ResultString, N>, L>
+parse_csv(String const& src, csv_parser_settings<typename String::value_type> settings = csv_parser_settings<typename String::value_type>()) {
+	typedef typename String::value_type value_type;
+	subbed_array<subbed_array<ResultString, N>, L> result = {};
+	result.window(0, 1);
+	result.back().window(0, 0);
+	auto delimiters = sprout::make_string(settings.delimiter(), value_type('\r'), value_type('\n'));
+	auto first = sprout::begin(src), last = sprout::end(src);
+	while (first != last) {
+		if (*first == settings.quote()) {
+			// quoted element
+			++first;
+			auto end_quote = sprout::find(first, last, settings.quote());
+			while (true) {
+				if (end_quote == last) {
+					throw 0;
+				}
+				auto next = sprout::next(end_quote);
+				if (next != last) {
+					if (*next == settings.escape()) {
+						// escaped quote
+						++next;
+						end_quote = sprout::find(next, last, settings.quote());
+						continue;
+					}
+					if (!sprout::any_of_equal(delimiters.begin(), delimiters.end(), *next)) {
+						throw 0;
+					}
+					if (*next == value_type('\r') && sprout::next(next) != last && *sprout::next(next) == value_type('\n')) {
+						++next;
+					}
+				}
+				result.back().push_back(
+					ResultString(sprout::addressof(*first), sprout::distance(first, end_quote))
+					);
+				first = next;
+				break;
+			}
+		} else {
+			// no quoted element
+			auto next = sprout::find_first_of(first, last, delimiters.begin(), delimiters.end());
+			if (next != last) {
+				if (*next == value_type('\r') && sprout::next(next) != last && *sprout::next(next) == value_type('\n')) {
+					++next;
+				}
+			}
+			result.back().push_back(
+				ResultString(sprout::addressof(*first), sprout::distance(first, next))
+				);
+			first = next;
+		}
+		if (first != last) {
+			if ((*first == value_type('\r') || *first == value_type('\n')) && sprout::next(first) != last) {
+				result.offset(0, 1);
+				result.back().window(0, 0);
+			}
+			++first;
+		}
+	}
+	return result;
+}
+
+#include <iostream>
+#include <sprout/utility/string_view.hpp>
+
+int main() {
+	using namespace sprout::udl;
+	constexpr auto src = R"(
+(no quoted),a,b,c
+(quoted),"d","e","f"
+(escaped),"""g""","""h""","""i"""
+(comma),"j,k","l,m","n,o"
+(new line),"p
+q","r
+s","t
+u"
+)"_sv;
+	constexpr auto result = parse_csv<16, 16>(src);
+	for (auto const& field : result) {
+		for (auto const& elem : field) {
+			std::cout
+				<< elem << std::endl
+				<< "----" << std::endl
+				;
+		}
+		std::cout
+			<< "----------------------------------------" << std::endl
+			;
+	}
+}