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/*
* Copyright 2019 by its authors. See AUTHORS.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef EINA_STRING_VIEW_HH_
#define EINA_STRING_VIEW_HH_
#include <string>
#include <iterator>
#include <stdexcept>
#include <algorithm>
#include <eina_throw.hh>
namespace efl { namespace eina {
template <typename CharT, typename Traits = std::char_traits<CharT> >
class basic_string_view
{
public:
// Types:
typedef Traits traits_type;
typedef CharT value_type;
typedef CharT& reference;
typedef CharT const& const_reference;
typedef CharT* pointer;
typedef CharT const* const_pointer;
typedef const_pointer const_iterator;
typedef const_iterator iterator;
typedef std::reverse_iterator<iterator> reverse_iterator;
typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
typedef std::ptrdiff_t difference_type;
typedef std::size_t size_type;
// Constants:
static constexpr size_type npos = size_type(-1);
// Constructors:
constexpr basic_string_view() noexcept
: _str(nullptr), _len(0)
{}
basic_string_view(basic_string_view<CharT, Traits> const& other) noexcept = default;
basic_string_view(basic_string_view<CharT, Traits>&& other) noexcept = default;
template<typename Allocator>
basic_string_view(std::basic_string<CharT, Traits, Allocator> const& str) noexcept
: _str(str.data()), _len(str.length())
{}
basic_string_view(CharT const* c_str)
: _str(c_str), _len(Traits::length(c_str))
{}
basic_string_view(std::nullptr_t)
: _str(NULL), _len(0)
{}
// basic_string_view(CharT const* c_str, size_type len) noexcept
// : _str(c_str), _len(len)
// {}
// Assignment:
basic_string_view<CharT, Traits>& operator=(basic_string_view<CharT, Traits> const& other) noexcept = default;
basic_string_view<CharT, Traits>& operator=(basic_string_view<CharT, Traits>&& other) noexcept = default;
// Iterators
const_iterator begin() const noexcept { return _str; }
const_iterator cbegin() const noexcept { return _str; }
const_iterator end() const noexcept { return _str + _len; }
const_iterator cend() const noexcept { return _str + _len; }
const_reverse_iterator rbegin() const noexcept { return const_reverse_iterator(end()); }
const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(end()); }
const_reverse_iterator rend() const noexcept { return const_reverse_iterator(begin()); }
const_reverse_iterator crend() const noexcept { return const_reverse_iterator(begin()); }
// Capacity:
size_type size() const noexcept { return _len; }
size_type length() const noexcept { return _len; }
bool empty() const noexcept { return _len == 0; }
// Element access:
const_reference operator[](size_type pos) const { return _str[pos]; }
const_reference at(size_type pos) const
{
if (pos >= _len)
EFL_CXX_THROW(std::out_of_range("efl::eina::basic_string_view::at"));
return _str[pos];
}
const_reference front() const { return _str[0]; }
const_reference back() const { return _str[_len-1]; }
// Operations:
CharT const* data() const noexcept { return _str; }
size_type copy(CharT* s, size_type len, size_type pos = 0) const
{
Traits::copy(s, _str+pos, len);
return len;
}
int compare(basic_string_view<CharT, Traits> const& s) const
{
const int cmp = Traits::compare(_str, s._str, (std::min)(_len, s._len));
return cmp != 0 ? cmp : ( _len == s._len ? 0 : _len < s._len ? -1 : 1 );
}
int compare(size_type pos, size_type len, basic_string_view<CharT, Traits> const& s) const
{
const int cmp = Traits::compare(_str+pos, s._str, (std::min)(len, s._len));
return cmp != 0 ? cmp : ( len == s._len ? 0 : len < s._len ? -1 : 1 );
}
int compare(size_type pos1, size_type len1, basic_string_view<CharT, Traits> const& s, size_type pos2, size_type len2) const
{
const int cmp = Traits::compare(_str+pos1, s._str+pos2, (std::min)(len1, len2));
return cmp != 0 ? cmp : ( len1 == len2 ? 0 : len1 < len2 ? -1 : 1 );
}
bool starts_with(CharT c) const
{
return !empty() && Traits::eq(c, front());
}
bool starts_with(basic_string_view<CharT, Traits> const& s) const
{
return _len >= s._len && Traits::compare(_str, s._str, s._len) == 0;
}
bool ends_with(CharT c) const
{
return !empty() && Traits::eq(c, back());
}
bool ends_with(basic_string_view<CharT, Traits> const& s) const
{
return _len >= s._len && Traits::compare(_str + _len - s._len, s._str, s._len) == 0;
}
size_type find(basic_string_view<CharT, Traits> const& s) const
{
const_iterator iter = std::search(cbegin(), cend(), s.cbegin(), s.cend(), Traits::eq);
return iter == cend () ? npos : std::distance(cbegin(), iter);
}
size_type find(basic_string_view<CharT, Traits> const& s, size_type pos) const
{
if (pos >= _len)
return npos;
const_iterator iter = std::search(cbegin()+pos, cend(), s.cbegin(), s.cend(), Traits::eq);
return iter == cend () ? npos : std::distance(cbegin(), iter);
}
size_type find(CharT c) const
{
const_iterator iter = std::find_if(cbegin(), cend(), [=](CharT val) { return Traits::eq(c, val); });
return iter == cend() ? npos : std::distance(cbegin(), iter);
}
size_type find(CharT c, size_type pos) const
{
if (pos >= _len)
return npos;
const_iterator iter = std::find_if(cbegin()+pos, cend(), [=](CharT val) { return Traits::eq(c, val); });
return iter == cend() ? npos : std::distance(cbegin(), iter);
}
size_type rfind(basic_string_view<CharT, Traits> const& s) const
{
const_reverse_iterator iter = std::search(crbegin(), crend(), s.crbegin(), s.crend(), Traits::eq);
return iter == crend() ? npos : reverse_distance(crbegin(), iter) - s.lenght();
}
size_type rfind(basic_string_view<CharT, Traits> const& s, size_type pos) const
{
if (pos >= _len)
return npos;
const_reverse_iterator iter = std::search(crbegin()+pos, crend(), s.crbegin(), s.crend(), Traits::eq);
return iter == crend() ? npos : reverse_distance(crbegin(), iter) - s.lenght();
}
size_type rfind(CharT c) const
{
const_reverse_iterator iter = std::find_if(crbegin(), crend(), [&](CharT val) { return Traits::eq(c, val); });
return iter == crend() ? npos : reverse_distance(crbegin(), iter);
}
size_type rfind(CharT c, size_type pos) const
{
pos = (pos >= _len) ? 0 : _len - pos - 1;
const_reverse_iterator iter = std::find_if(crbegin()+pos, crend(), [&](CharT val) { return Traits::eq(c, val); });
return iter == crend() ? npos : reverse_distance(crbegin(), iter);
}
size_type find_first_of(CharT c) const { return find(c); }
size_type find_last_of (CharT c) const { return rfind(c); }
size_type find_first_of(basic_string_view<CharT, Traits> const& s) const
{
const_iterator iter = std::find_first_of(cbegin(), cend(), s.cbegin(), s.cend(), Traits::eq);
return iter == cend() ? npos : std::distance(cbegin(), iter);
}
size_type find_last_of(basic_string_view<CharT, Traits> const& s) const
{
const_reverse_iterator iter = std::find_first_of(crbegin(), crend(), s.cbegin(), s.cend(), Traits::eq);
return iter == crend () ? npos : reverse_distance(crbegin(), iter);
}
size_type find_first_not_of(basic_string_view<CharT, Traits> const& s) const
{
const_iterator iter = find_not_of(cbegin(), cend(), s);
return iter == cend() ? npos : std::distance(cbegin(), iter);
}
size_type find_first_not_of(CharT c) const
{
for (const_iterator iter = cbegin(); iter != cend(); ++iter)
if (!Traits::eq(c, *iter))
return std::distance(cbegin(), iter);
return npos;
}
size_type find_last_not_of(basic_string_view<CharT, Traits> const& s) const
{
const_reverse_iterator iter = find_not_of(crbegin(), crend(), s);
return iter == crend() ? npos : reverse_distance(crbegin(), iter);
}
size_type find_last_not_of(CharT c) const
{
for (const_reverse_iterator iter = crbegin(); iter != crend(); ++iter)
if (!Traits::eq(c, *iter))
return reverse_distance(crbegin(), iter);
return npos;
}
// XXX: returning std::string instead of eina::string_view
std::basic_string<CharT, Traits> substr(size_type pos, size_type len=npos) const
{
if (pos > size())
EFL_CXX_THROW(std::out_of_range("efl::eina::string_view::substr"));
if (len == npos || pos + len > size())
len = size () - pos;
return std::basic_string<CharT, Traits>(data() + pos, len);
}
// Conversions:
std::basic_string<CharT, Traits> to_string() const
{
return std::basic_string<CharT, Traits>(_str, _len);
}
std::basic_string<CharT, Traits> str() const
{
return to_string();
}
CharT const* c_str() const noexcept { return data(); }
template<typename Allocator>
operator std::basic_string<CharT, Traits, Allocator>() const
{
return std::basic_string<CharT, Traits, Allocator>(_str, _len);
}
void swap(basic_string_view<CharT, Traits>& s)
{
std::swap(_str, s._str);
std::swap(_len, s._len);
}
// Comparison operators:
friend inline bool operator==(basic_string_view<CharT, Traits> const& s1, basic_string_view<CharT, Traits> const& s2)
{
if (s1.size() != s2.size())
return false;
return s1.compare(s2) == 0;
}
friend inline bool operator!=(basic_string_view<CharT, Traits> const& s1, basic_string_view<CharT, Traits> const& s2)
{
return !(s1 == s2);
}
friend inline bool operator<(basic_string_view<CharT, Traits> const& s1, basic_string_view<CharT, Traits> const& s2)
{
return s1.compare(s2) < 0;
}
friend inline bool operator>(basic_string_view<CharT, Traits> const& s1, basic_string_view<CharT, Traits> const& s2)
{
return s2 < s1;
}
friend inline bool operator<=(basic_string_view<CharT, Traits> const& s1, basic_string_view<CharT, Traits> const& s2)
{
return !(s2 < s1);
}
friend inline bool operator>=(basic_string_view<CharT, Traits> const& s1, basic_string_view<CharT, Traits> const& s2)
{
return !(s1 < s2);
}
private:
template <typename Iterator>
size_type reverse_distance(Iterator first, Iterator last) const
{
return _len - 1 - std::distance(first, last);
}
template <typename Iterator>
Iterator find_not_of(Iterator first, Iterator last, basic_string_view<CharT, Traits>& s) const
{
for (; first != last; ++first)
if (0 == Traits::find(s._str, s._len, *first))
return first;
return last;
}
const CharT* _str;
size_type _len;
};
// Stream operation
template<class CharT, class Traits>
inline std::basic_ostream<CharT, Traits>&
operator<<(std::basic_ostream<CharT, Traits>& os, basic_string_view<CharT,Traits> const& s)
{
return os << s.data();
}
template <typename CharT, typename Traits>
void swap(basic_string_view<CharT, Traits>& s1, basic_string_view<CharT, Traits>& s2)
{
s1.swap(s2);
}
// Instantiations:
typedef basic_string_view<char> string_view;
typedef basic_string_view<wchar_t> wstring_view;
typedef basic_string_view<char16_t> u16string_view;
typedef basic_string_view<char32_t> u32string_view;
} }
#endif