[ox/std] Add StringView split and find functions

deps/ox/src/ox/std/stringview.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 - 2022 gary@drinkingtea.net
+ * Copyright 2015 - 2023 gary@drinkingtea.net
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -12,10 +12,11 @@
 #include <string_view>
 #endif
 
+#include "bit.hpp"
 #include "iterator.hpp"
 #include "strops.hpp"
 #include "types.hpp"
-#include "bit.hpp"
+#include "vector.hpp"
 
 namespace ox {
 
@@ -223,8 +224,19 @@ class StringView {
 
 		[[nodiscard]]
 		constexpr auto substr(std::size_t pos) const noexcept {
+			if (m_len >= pos) {
 				return StringView(m_str + pos, m_len - pos);
 			}
+			return StringView();
+		}
+
+		[[nodiscard]]
+		constexpr auto substr(std::size_t start, std::size_t end) const noexcept {
+			if (m_len >= start && end >= start) {
+				return StringView(m_str + start, end - start);
+			}
+			return StringView();
+		}
 
 		constexpr auto operator[](std::size_t i) const noexcept {
 			return m_str[i];
@@ -276,6 +288,58 @@ constexpr bool endsWith(CRStringView base, CRStringView ending) noexcept {
 	return base.len() >= endingLen && ox_strcmp(base.data() + (base.len() - endingLen), ending) == 0;
 }
 
+constexpr std::size_t find(CRStringView str, char search) noexcept {
+	std::size_t i = 0;
+	for (; i < str.len(); ++i) {
+		if (str[i] == search) {
+			break;
+		}
+	}
+	return i;
+}
+
+constexpr std::size_t find(CRStringView str, CRStringView search) noexcept {
+	std::size_t i = 0;
+	for (; i < str.len(); ++i) {
+		if (beginsWith(str.substr(i), search)) {
+			break;
+		}
+	}
+	return i;
+}
+
+template<std::size_t smallSz = 0>
+constexpr ox::Vector<ox::StringView, smallSz> split(CRStringView str, char del) noexcept {
+	ox::Vector<ox::StringView, smallSz> out;
+	constexpr auto nextSeg = [](CRStringView current, char del) {
+		return current.substr(find(current, del) + 1);
+	};
+	for (auto current = str; current.len(); current = nextSeg(current, del)) {
+		const auto next = find(current, del);
+		if (const auto s = current.substr(0, next); s.len()) {
+			out.emplace_back(s);
+		}
+		current = current.substr(next);
+	}
+	return out;
+}
+
+template<std::size_t smallSz = 0>
+constexpr ox::Vector<ox::StringView, smallSz> split(CRStringView str, CRStringView del) noexcept {
+	ox::Vector<ox::StringView, smallSz> out;
+	constexpr auto nextSeg = [](CRStringView current, CRStringView del) {
+		return current.substr(find(current, del) + del.len());
+	};
+	for (auto current = str; current.len(); current = nextSeg(current, del)) {
+		const auto next = find(current, del);
+		if (const auto s = current.substr(0, next); s.len()) {
+			out.emplace_back(s);
+		}
+		current = current.substr(next);
+	}
+	return out;
+}
+
 #ifdef OX_USE_STDLIB
 constexpr auto toStdStringView(CRStringView sv) noexcept {
 	return std::string_view(sv.data(), sv.bytes());

deps/ox/src/ox/std/test/CMakeLists.txt

@@ -18,3 +18,4 @@ add_test("[ox/std] HashMap" StdTest "HashMap")
 add_test("[ox/std] HeapMgr" StdTest malloc)
 add_test("[ox/std] Serialize-Int" StdTest "Serialize-Int")
 add_test("[ox/std] BufferWriter" StdTest "BufferWriter")
+add_test("[ox/std] StringSplit" StdTest "StringSplit")

deps/ox/src/ox/std/test/tests.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 - 2022 gary@drinkingtea.net
+ * Copyright 2015 - 2023 gary@drinkingtea.net
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -155,6 +155,73 @@ static std::map<ox::String, ox::Error(*)()> tests = {
 			return OxError(0);
 		}
 	},
+	{
+		"StringSplit",
+		[] {
+			ox::StringView sv = "ab.cd";
+			auto list = ox::split(sv, ".");
+			oxExpect(list.size(), 2u);
+			oxExpect(list[0], "ab");
+			oxExpect(list[1], "cd");
+			sv = "ab.cd.fg";
+			list = ox::split(sv, ".");
+			oxExpect(list.size(), 3u);
+			oxExpect(list[0], "ab");
+			oxExpect(list[1], "cd");
+			oxExpect(list[2], "fg");
+			sv = "ab.cd.";
+			list = ox::split(sv, ".");
+			oxExpect(list.size(), 2u);
+			oxExpect(list[0], "ab");
+			oxExpect(list[1], "cd");
+			sv = ".ab.cd.";
+			list = ox::split(sv, ".");
+			oxExpect(list.size(), 2u);
+			oxExpect(list[0], "ab");
+			oxExpect(list[1], "cd");
+			sv = ".";
+			list = ox::split(sv, ".");
+			oxExpect(list.size(), 0u);
+			sv = ".";
+			list = ox::split(sv, ".");
+			oxExpect(list.size(), 0u);
+			sv = "";
+			list = ox::split(sv, ".");
+			oxExpect(list.size(), 0u);
+			// split by single char
+			sv = "ab.cd";
+			list = ox::split(sv, '.');
+			oxExpect(list.size(), 2u);
+			oxExpect(list[0], "ab");
+			oxExpect(list[1], "cd");
+			sv = "ab.cd.fg";
+			list = ox::split(sv, '.');
+			oxExpect(list.size(), 3u);
+			oxExpect(list[0], "ab");
+			oxExpect(list[1], "cd");
+			oxExpect(list[2], "fg");
+			sv = "ab.cd.";
+			list = ox::split(sv, '.');
+			oxExpect(list.size(), 2u);
+			oxExpect(list[0], "ab");
+			oxExpect(list[1], "cd");
+			sv = ".ab.cd.";
+			list = ox::split(sv, '.');
+			oxExpect(list.size(), 2u);
+			oxExpect(list[0], "ab");
+			oxExpect(list[1], "cd");
+			sv = ".";
+			list = ox::split(sv, '.');
+			oxExpect(list.size(), 0u);
+			sv = ".";
+			list = ox::split(sv, '.');
+			oxExpect(list.size(), 0u);
+			sv = "";
+			list = ox::split(sv, '.');
+			oxExpect(list.size(), 0u);
+			return OxError(0);
+		}
+	},
 };
 
 int main(int argc, const char **args) {