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| -rw-r--r-- | include/o3tl/string_view.hxx | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/include/o3tl/string_view.hxx b/include/o3tl/string_view.hxx new file mode 100644 index 000000000..f6c2a4aa7 --- /dev/null +++ b/include/o3tl/string_view.hxx @@ -0,0 +1,487 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */ +/* + * This file is part of the LibreOffice project. + * + * 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 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + */ + +#pragma once + +#include <sal/config.h> + +#include <cassert> +#include <cstddef> +#include <string> +#include <string_view> + +#include <o3tl/intcmp.hxx> +#include <rtl/ustring.h> +#include <rtl/math.h> + +namespace o3tl +{ +// Like OUString::equalsIgnoreAsciiCase, but for two std::u16string_view: +inline bool equalsAscii(std::u16string_view s1, const char* s2) +{ + return rtl_ustr_ascii_compare_WithLength(s1.data(), s1.size(), s2) == 0; +} + +// Like OUString::equalsAsciiL +inline bool equalsAscii(std::u16string_view s1, std::string_view s2) +{ + return rtl_ustr_ascii_shortenedCompare_WithLength(s1.data(), s1.size(), s2.data(), s2.size()) + == 0; +} + +// Like OUString::equalsIgnoreAsciiCase, but for two std::u16string_view: +inline bool equalsIgnoreAsciiCase(std::u16string_view s1, std::u16string_view s2) +{ + if (s1.size() != s2.size()) + return false; + if (s1.data() == s2.data()) + return true; + return rtl_ustr_compareIgnoreAsciiCase_WithLength(s1.data(), s1.size(), s2.data(), s2.size()) + == 0; +}; + +inline bool equalsIgnoreAsciiCase(std::string_view s1, std::string_view s2) +{ + if (s1.size() != s2.size()) + return false; + if (s1.data() == s2.data()) + return true; + return rtl_str_compareIgnoreAsciiCase_WithLength(s1.data(), s1.size(), s2.data(), s2.size()) + == 0; +}; + +// Like OUString::compareToIgnoreAsciiCase, but for two std::u16string_view: +inline int compareToIgnoreAsciiCase(std::u16string_view s1, std::u16string_view s2) +{ + return rtl_ustr_compareIgnoreAsciiCase_WithLength(s1.data(), s1.size(), s2.data(), s2.size()); +}; + +// Like OUString::matchIgnoreAsciiCase, but for two std::u16string_view: +inline bool matchIgnoreAsciiCase(std::u16string_view s1, std::u16string_view s2, + sal_Int32 fromIndex = 0) +{ + return rtl_ustr_shortenedCompareIgnoreAsciiCase_WithLength( + s1.data() + fromIndex, s1.size() - fromIndex, s2.data(), s2.size(), s2.size()) + == 0; +} + +// Similar to O[U]String::getToken, returning the first token of a std::[u16]string_view starting +// at a given position. +// +// Attention: There are two sets of o3tl::getToken overloads here. This first set has an interface +// based on std::size_t length parameters, and its semantics don't match those of +// O[U]String::getToken exactly (buf if needed, it can be extended to return the n'th token instead +// of just the first, and/or support an initial position of npos, to make the semantics match). +template <typename charT, typename traits = std::char_traits<charT>> +inline std::basic_string_view<charT, traits> getToken(std::basic_string_view<charT, traits> sv, + charT delimiter, std::size_t& position) +{ + assert(position <= sv.size()); + auto const n = sv.find(delimiter, position); + std::basic_string_view<charT, traits> t; + if (n == std::string_view::npos) + { + t = sv.substr(position); + position = std::string_view::npos; + } + else + { + t = sv.substr(position, n - position); + position = n + 1; + } + return t; +} +// The following two overloads prevent overload resolution mistakes that would occur with their +// template counterpart, when sv is of a type that is implicitly convertible to basic_string_view +// (like OString or OUString), in which case overload resolution would erroneously choose the +// three-argument overloads (taking sv, nToken, cTok) from the second set of +// o3tl::getToken overloads below: +inline std::string_view getToken(std::string_view sv, char delimiter, std::size_t& position) +{ + return getToken<char>(sv, delimiter, position); +} +inline std::u16string_view getToken(std::u16string_view sv, char16_t delimiter, + std::size_t& position) +{ + return getToken<char16_t>(sv, delimiter, position); +} + +// Similar to O[U]String::getToken. +// +// Attention: There are two sets of o3tl::getToken overloads here. This second set has an +// interface based on sal_Int32 length parameters, and is meant to be a drop-in replacement for +// O[U]String::getToken. +template <typename charT, typename traits = std::char_traits<charT>> +inline std::basic_string_view<charT, traits> getToken(std::basic_string_view<charT, traits> pStr, + sal_Int32 nToken, charT cTok, + sal_Int32& rnIndex) +{ + assert(o3tl::IntCmp(rnIndex) <= o3tl::IntCmp(pStr.size())); + + // Return an empty string and set rnIndex to -1 if either nToken or rnIndex is + // negative: + if (rnIndex >= 0 && nToken >= 0) + { + const charT* pOrgCharStr = pStr.data(); + const charT* pCharStr = pOrgCharStr + rnIndex; + sal_Int32 nLen = pStr.size() - rnIndex; + sal_Int32 nTokCount = 0; + const charT* pCharStrStart = pCharStr; + while (nLen > 0) + { + if (*pCharStr == cTok) + { + nTokCount++; + + if (nTokCount > nToken) + break; + if (nTokCount == nToken) + pCharStrStart = pCharStr + 1; + } + + pCharStr++; + nLen--; + } + if (nTokCount >= nToken) + { + if (nLen > 0) + rnIndex = pCharStr - pOrgCharStr + 1; + else + rnIndex = -1; + return std::basic_string_view<charT, traits>(pCharStrStart, pCharStr - pCharStrStart); + } + } + + rnIndex = -1; + return std::basic_string_view<charT, traits>(); +} +// The following two overloads prevent deduction failures that would occur with their template +// counterpart, when sv is of a type that is implicitly convertible to basic_string_view (like +// OString or OUString): +inline std::string_view getToken(std::string_view sv, sal_Int32 nToken, char cTok, + sal_Int32& rnIndex) +{ + return getToken<char>(sv, nToken, cTok, rnIndex); +} +inline std::u16string_view getToken(std::u16string_view sv, sal_Int32 nToken, char16_t cTok, + sal_Int32& rnIndex) +{ + return getToken<char16_t>(sv, nToken, cTok, rnIndex); +} +inline std::string_view getToken(std::string_view sv, sal_Int32 nToken, char cTok) +{ + sal_Int32 nIndex = 0; + return getToken<char>(sv, nToken, cTok, nIndex); +} +inline std::u16string_view getToken(std::u16string_view sv, sal_Int32 nToken, char16_t cTok) +{ + sal_Int32 nIndex = 0; + return getToken<char16_t>(sv, nToken, cTok, nIndex); +} + +// Implementations of C++20 std::basic_string_view::starts_with and +// std::basic_string_view::ends_with, until we can use those directly on all platforms: +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool starts_with(std::basic_string_view<charT, traits> sv, + std::basic_string_view<charT, traits> x) noexcept +{ +#if defined __cpp_lib_starts_ends_with + return sv.starts_with(x); +#else + return sv.substr(0, x.size()) == x; +#endif +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool starts_with(std::basic_string_view<charT, traits> sv, charT x) noexcept +{ +#if defined __cpp_lib_starts_ends_with + return sv.starts_with(x); +#else + return !sv.empty() && traits::eq(sv.front(), x); +#endif +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool starts_with(std::basic_string_view<charT, traits> sv, charT const* x) +{ +#if defined __cpp_lib_starts_ends_with + return sv.starts_with(x); +#else + return starts_with(sv, std::basic_string_view<charT, traits>(x)); +#endif +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool ends_with(std::basic_string_view<charT, traits> sv, + std::basic_string_view<charT, traits> x) noexcept +{ +#if defined __cpp_lib_ends_ends_with + return sv.ends_with(x); +#else + return sv.size() >= x.size() + && sv.compare(sv.size() - x.size(), std::basic_string_view<charT, traits>::npos, x) == 0; +#endif +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool ends_with(std::basic_string_view<charT, traits> sv, charT x) noexcept +{ +#if defined __cpp_lib_ends_ends_with + return sv.ends_with(x); +#else + return !sv.empty() && traits::eq(sv.back(), x); +#endif +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool ends_with(std::basic_string_view<charT, traits> sv, charT const* x) +{ +#if defined __cpp_lib_ends_ends_with + return sv.ends_with(x); +#else + return ends_with(sv, std::basic_string_view<charT, traits>(x)); +#endif +} +// The following overloads prevent deduction failures that would occur with their template +// counterparts, when x is of a type that is implicitly convertible to basic_string_view (like +// OString or OUString, and we only bother to provide overloads for the char and char16_t cases, not +// also for char32_t and wchar_t, nor for C++20 char8_t): +constexpr bool starts_with(std::string_view sv, std::string_view x) noexcept +{ + return starts_with<char>(sv, x); +} +constexpr bool starts_with(std::u16string_view sv, std::u16string_view x) noexcept +{ + return starts_with<char16_t>(sv, x); +} +constexpr bool ends_with(std::string_view sv, std::string_view x) noexcept +{ + return ends_with<char>(sv, x); +} +constexpr bool ends_with(std::u16string_view sv, std::u16string_view x) noexcept +{ + return ends_with<char16_t>(sv, x); +} + +// Variants of C++20 std::basic_string_view::starts_with and +// std::basic_string_view::ends_with that have a rest out parameter, similar to our OString and +// OUString startsWith and endsWith member functions: +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool starts_with(std::basic_string_view<charT, traits> sv, + std::basic_string_view<charT, traits> x, + std::basic_string_view<charT, traits>* rest) noexcept +{ + assert(rest != nullptr); + auto const found = starts_with(sv, x); + if (found) + { + *rest = sv.substr(x.length()); + } + return found; +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool starts_with(std::basic_string_view<charT, traits> sv, charT x, + std::basic_string_view<charT, traits>* rest) noexcept +{ + assert(rest != nullptr); + auto const found = starts_with(sv, x); + if (found) + { + *rest = sv.substr(1); + } + return found; +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool starts_with(std::basic_string_view<charT, traits> sv, charT const* x, + std::basic_string_view<charT, traits>* rest) +{ + assert(rest != nullptr); + auto const found = starts_with(sv, x); + if (found) + { + *rest = sv.substr(traits::length(x)); + } + return found; +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool ends_with(std::basic_string_view<charT, traits> sv, + std::basic_string_view<charT, traits> x, + std::basic_string_view<charT, traits>* rest) noexcept +{ + assert(rest != nullptr); + auto const found = ends_with(sv, x); + if (found) + { + *rest = sv.substr(0, sv.length() - x.length()); + } + return found; +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool ends_with(std::basic_string_view<charT, traits> sv, charT x, + std::basic_string_view<charT, traits>* rest) noexcept +{ + assert(rest != nullptr); + auto const found = ends_with(sv, x); + if (found) + { + *rest = sv.substr(0, sv.length() - 1); + } + return found; +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool ends_with(std::basic_string_view<charT, traits> sv, charT const* x, + std::basic_string_view<charT, traits>* rest) +{ + assert(rest != nullptr); + auto const found = ends_with(sv, x); + if (found) + { + *rest = sv.substr(0, sv.length() - traits::length(x)); + } + return found; +} +// The following overloads prevent deduction failures that would occur with their template +// counterparts, when x is of a type that is implicitly convertible to basic_string_view (like +// OString or OUString, and we only bother to provide overloads for the char and char16_t cases, not +// also for char32_t and wchar_t, nor for C++20 char8_t): +constexpr bool starts_with(std::string_view sv, std::string_view x, std::string_view* rest) noexcept +{ + return starts_with<char>(sv, x, rest); +} +constexpr bool starts_with(std::u16string_view sv, std::u16string_view x, + std::u16string_view* rest) noexcept +{ + return starts_with<char16_t>(sv, x, rest); +} +constexpr bool ends_with(std::string_view sv, std::string_view x, std::string_view* rest) noexcept +{ + return ends_with<char>(sv, x, rest); +} +constexpr bool ends_with(std::u16string_view sv, std::u16string_view x, + std::u16string_view* rest) noexcept +{ + return ends_with<char16_t>(sv, x, rest); +} + +namespace internal +{ +// copy of implIsWhitespace from sal/rtl/strtmpl.hxx +inline bool implIsWhitespace(sal_Unicode c) +{ + /* Space or Control character? */ + if ((c <= 32) && c) + return true; + + /* Only in the General Punctuation area Space or Control characters are included? */ + if ((c < 0x2000) || (c > 0x206F)) + return false; + + if (((c >= 0x2000) && (c <= 0x200B)) || /* All Spaces */ + (c == 0x2028) || /* LINE SEPARATOR */ + (c == 0x2029)) /* PARAGRAPH SEPARATOR */ + return true; + + return false; +} +} // namespace internal + +// Like OUString::trim, but for std::u16string_view: +// copy of the trimView code from sal/rtl/strtmpl.hxx +inline std::u16string_view trim(std::u16string_view str) +{ + sal_Int32 nLen = str.size(); + sal_Int32 nPreSpaces = 0; + sal_Int32 nPostSpaces = 0; + sal_Int32 nIndex = str.size() - 1; + + while ((nPreSpaces < nLen) && internal::implIsWhitespace(*(str.data() + nPreSpaces))) + nPreSpaces++; + + while ((nIndex > nPreSpaces) && internal::implIsWhitespace(*(str.data() + nIndex))) + { + nPostSpaces++; + nIndex--; + } + + return std::u16string_view{ str.data() + nPreSpaces, + static_cast<size_t>(nLen - nPostSpaces - nPreSpaces) }; +} + +// Like OString::trim, but for std::string_view: +// copy of the trimView code from sal/rtl/strtmpl.hxx +inline std::string_view trim(std::string_view str) +{ + sal_Int32 nLen = str.size(); + sal_Int32 nPreSpaces = 0; + sal_Int32 nPostSpaces = 0; + sal_Int32 nIndex = str.size() - 1; + + while ((nPreSpaces < nLen) && internal::implIsWhitespace(*(str.data() + nPreSpaces))) + nPreSpaces++; + + while ((nIndex > nPreSpaces) && internal::implIsWhitespace(*(str.data() + nIndex))) + { + nPostSpaces++; + nIndex--; + } + + return std::string_view{ str.data() + nPreSpaces, + static_cast<size_t>(nLen - nPostSpaces - nPreSpaces) }; +} + +// Like OString::toInt32, but for std::string_view: +inline sal_Int32 toInt32(std::u16string_view str, sal_Int16 radix = 10) +{ + sal_Int64 n = rtl_ustr_toInt64_WithLength(str.data(), radix, str.size()); + if (n < SAL_MIN_INT32 || n > SAL_MAX_INT32) + n = 0; + return n; +} +inline sal_Int32 toInt32(std::string_view str, sal_Int16 radix = 10) +{ + sal_Int64 n = rtl_str_toInt64_WithLength(str.data(), radix, str.size()); + if (n < SAL_MIN_INT32 || n > SAL_MAX_INT32) + n = 0; + return n; +} + +// Like OString::toUInt32, but for std::string_view: +inline sal_uInt32 toUInt32(std::u16string_view str, sal_Int16 radix = 10) +{ + sal_Int64 n = rtl_ustr_toInt64_WithLength(str.data(), radix, str.size()); + if (n < 0 || n > SAL_MAX_UINT32) + n = 0; + return n; +} +inline sal_uInt32 toUInt32(std::string_view str, sal_Int16 radix = 10) +{ + sal_Int64 n = rtl_str_toInt64_WithLength(str.data(), radix, str.size()); + if (n < 0 || n > SAL_MAX_UINT32) + n = 0; + return n; +} + +// Like OString::toInt64, but for std::string_view: +inline sal_Int64 toInt64(std::u16string_view str, sal_Int16 radix = 10) +{ + return rtl_ustr_toInt64_WithLength(str.data(), radix, str.size()); +} +inline sal_Int64 toInt64(std::string_view str, sal_Int16 radix = 10) +{ + return rtl_str_toInt64_WithLength(str.data(), radix, str.size()); +} + +// Like OString::toDouble, but for std::string_view: +inline double toDouble(std::u16string_view str) +{ + return rtl_math_uStringToDouble(str.data(), str.data() + str.size(), '.', 0, nullptr, nullptr); +} +inline double toDouble(std::string_view str) +{ + return rtl_math_stringToDouble(str.data(), str.data() + str.size(), '.', 0, nullptr, nullptr); +} +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */ |