Program Listing for File text.hpp
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/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2022 Maarten L. hekkelman
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <mcfp/detail/charconv.hpp>
namespace mcfp
{
template <typename T>
using charconv = typename detail::charconv<T>;
template <template<class...> class Op, class... Args>
constexpr inline bool is_detected_v = detail::is_detected_v<Op,Args...>;
// --------------------------------------------------------------------
class word_wrapper : public std::vector<std::string_view>
{
public:
word_wrapper(std::string_view text, size_t width)
: m_width(width)
{
std::string_view::size_type line_start = 0, line_end = text.find('\n');
for (;;)
{
auto line = text.substr(line_start, line_end - line_start);
if (line.empty())
this->push_back(line);
else
{
auto lines = wrap_line(line);
this->insert(this->end(), lines.begin(), lines.end());
}
if (line_end == std::string_view::npos)
break;
line_start = line_end + 1;
line_end = text.find('\n', line_start);
}
}
private:
std::vector<std::string_view> wrap_line(std::string_view line)
{
std::vector<std::string_view> result;
std::vector<size_t> offsets = { 0 };
auto b = line.begin();
while (b != line.end())
{
auto e = next_line_break(b, line.end());
offsets.push_back(e - line.begin());
b = e;
}
size_t count = offsets.size() - 1;
std::vector<size_t> minima(count + 1, std::numeric_limits<size_t>::max());
minima[0] = 0;
std::vector<size_t> breaks(count + 1, 0);
for (size_t i = 0; i < count; ++i)
{
size_t j = i + 1;
while (j <= count)
{
size_t w = offsets[j] - offsets[i];
if (w > m_width)
break;
while (w > 0 and std::isspace(line[offsets[i] + w - 1]))
--w;
size_t cost = minima[i];
if (j < count) // last line may be shorter
cost += (m_width - w) * (m_width - w);
if (cost < minima[j])
{
minima[j] = cost;
breaks[j] = i;
}
++j;
}
}
size_t j = count;
while (j > 0)
{
size_t i = breaks[j];
result.push_back(line.substr(offsets[i], offsets[j] - offsets[i]));
j = i;
}
reverse(result.begin(), result.end());
return result;
}
std::string_view::const_iterator next_line_break(std::string_view::const_iterator text, std::string_view::const_iterator end)
{
if (text == end)
return text;
enum LineBreakClass
{
OP, // OpenPunctuation,
CL, // ClosePunctuation,
CP, // CloseParenthesis,
QU, // Quotation,
EX, // Exlamation,
SY, // SymbolAllowingBreakAfter,
IS, // InfixNumericSeparator,
PR, // PrefixNumeric,
PO, // PostfixNumeric,
NU, // Numeric,
AL, // Alphabetic,
HY, // Hyphen,
BA, // BreakAfter,
CM, // CombiningMark,
WJ, // WordJoiner,
MB, // MandatoryBreak,
SP, // Space,
};
static const LineBreakClass kASCII_LineBreakTable[128] = {
CM, CM, CM, CM, CM, CM, CM, CM,
CM, BA, MB, MB, MB, SP, CM, CM,
CM, CM, CM, CM, CM, CM, CM, CM,
CM, CM, CM, CM, CM, CM, CM, CM,
SP, EX, QU, AL, PR, PO, AL, QU,
OP, CP, AL, PR, IS, HY, IS, SY,
NU, NU, NU, NU, NU, NU, NU, NU,
NU, NU, IS, IS, AL, AL, AL, EX,
AL, AL, AL, AL, AL, AL, AL, AL,
AL, AL, AL, AL, AL, AL, AL, AL,
AL, AL, AL, AL, AL, AL, AL, AL,
AL, AL, AL, OP, PR, CP, AL, AL,
AL, AL, AL, AL, AL, AL, AL, AL,
AL, AL, AL, AL, AL, AL, AL, AL,
AL, AL, AL, AL, AL, AL, AL, AL,
AL, AL, AL, OP, BA, CL, AL, CM
};
enum BreakAction
{
DBK = 0, // direct break (blank in table)
IBK, // indirect break (% in table)
PBK, // prohibited break (^ in table)
CIB, // combining indirect break
CPB // combining prohibited break
};
static const BreakAction brkTable[15][15] = {
// OP CL CP QU EX SY IS PR PO NU AL HY BA CM WJ
/* OP */ { PBK, PBK, PBK, PBK, PBK, PBK, PBK, PBK, PBK, PBK, PBK, PBK, PBK, CPB, PBK },
/* CL */ { DBK, PBK, PBK, IBK, PBK, PBK, PBK, IBK, IBK, DBK, DBK, IBK, IBK, CIB, PBK },
/* CP */ { DBK, PBK, PBK, IBK, PBK, PBK, PBK, IBK, IBK, IBK, IBK, IBK, IBK, CIB, PBK },
/* QU */ { PBK, PBK, PBK, IBK, PBK, PBK, PBK, IBK, IBK, IBK, IBK, IBK, IBK, CIB, PBK },
/* EX */ { DBK, PBK, PBK, IBK, PBK, PBK, PBK, DBK, DBK, DBK, DBK, IBK, IBK, CIB, PBK },
/* SY */ { DBK, PBK, PBK, IBK, PBK, PBK, PBK, DBK, DBK, IBK, DBK, IBK, IBK, CIB, PBK },
/* IS */ { DBK, PBK, PBK, IBK, PBK, PBK, PBK, DBK, DBK, IBK, IBK, IBK, IBK, CIB, PBK },
/* PR */ { IBK, PBK, PBK, IBK, PBK, PBK, PBK, DBK, DBK, IBK, IBK, IBK, IBK, CIB, PBK },
/* PO */ { IBK, PBK, PBK, IBK, PBK, PBK, PBK, DBK, DBK, IBK, IBK, IBK, IBK, CIB, PBK },
/* NU */ { DBK, PBK, PBK, IBK, PBK, PBK, PBK, IBK, IBK, IBK, IBK, IBK, IBK, CIB, PBK },
/* AL */ { DBK, PBK, PBK, IBK, PBK, PBK, PBK, DBK, DBK, IBK, IBK, IBK, IBK, CIB, PBK },
/* HY */ { DBK, PBK, PBK, IBK, PBK, PBK, PBK, DBK, DBK, IBK, DBK, IBK, IBK, CIB, PBK },
/* BA */ { DBK, PBK, PBK, IBK, PBK, PBK, PBK, DBK, DBK, DBK, DBK, IBK, IBK, CIB, PBK },
/* CM */ { DBK, PBK, PBK, IBK, PBK, PBK, PBK, DBK, DBK, IBK, IBK, IBK, IBK, CIB, PBK },
/* WJ */ { IBK, PBK, PBK, IBK, PBK, PBK, PBK, IBK, IBK, IBK, IBK, IBK, IBK, CIB, PBK },
};
uint8_t ch = *text;
LineBreakClass cls;
if (ch < 128)
cls = kASCII_LineBreakTable[ch];
else
cls = AL;
if (cls == SP)
cls = WJ;
LineBreakClass ncls = cls;
while (++text != end and cls != MB)
{
ch = *text;
LineBreakClass lcls = ncls;
if (ch < 128)
ncls = kASCII_LineBreakTable[ch];
else
ncls = AL;
if (ncls == MB)
{
++text;
break;
}
if (ncls == SP)
continue;
BreakAction brk = brkTable[cls][ncls];
if (brk == DBK or (brk == IBK and lcls == SP))
break;
cls = ncls;
}
return text;
}
size_t m_width;
};
} // namespace mcfp