#include <cassert>
#include <iostream>
#include <iterator>
#include <stdexcept>
#include <string>
#include <vector>
///Undo a Wordwrap
const std::string Unwordwrap(const std::vector<std::string>& v) noexcept;
///Wordwrap the text to obtain lines of max_len characters
///If the string _must_ be seperable by spaces; a word can have a maximum length of max_len
const std::vector<std::string> Wordwrap(const std::string& s, const std::size_t max_len) noexcept;
const std::string Unwordwrap(
const std::vector<std::string>& v) noexcept
{
//Simply concatenate
std::string t;
for (const std::string& s: v) { t += s; }
return t;
}
const std::vector<std::string> Wordwrap(
const std::string& s_original, const std::size_t max_len) noexcept
{
if (max_len == 0)
{
throw std::logic_error("Cannot wordwrap for a max_len of zero");
}
//std::clog << "Wordwrap \'" << s_original << '\'' << std::endl;
std::string s{s_original};
assert(s.size() == s_original.size());
///Replace multiple spaces with '\b ', where x is a char not in the string
std::string::value_type x = '\b'; //Bell
{
const std::size_t sz = s.size();
///Replace spaces at beginning
for (std::size_t i=0; i!=sz; ++i)
{
if (s[i] == ' ')
s[i] = x;
else
break;
}
//Replace spaces at end
if (sz > 0)
{
//i!=0, because if s[0] is a space, it is already converted to bell
for (std::size_t i=sz-1; i!=0; ++i)
{
if (s[i] == ' ')
s[i] = x;
else
break;
}
}
///Replace " " by "\b "
for (std::size_t i=0; i!=sz-1; ++i)
{
if (s[i] == ' ' && s[i+1] == ' ')
s[i] = x;
else
break;
}
}
std::vector<std::string> v;
//Start the actual wordwrapping
while (!s.empty())
{
//TRACE(s);
//Is the word short enough?
if (s.size() < max_len)
{
//Copy entire word
v.push_back(s);
s = {};
assert(s.empty());
continue;
}
//No spaces, or space beyond max_len: cut word
if (s.find(' ') == std::string::npos || s.find(' ') > max_len)
{
v.push_back(s.substr(0,max_len));
s = s.substr(max_len,s.size() - max_len);
continue;
}
//Find last space before max_len
std::size_t len = s.find(' ');
assert(len != std::string::npos);
assert(len < s.size());
while (1)
{
const std::size_t new_len = s.find(' ',len + 1);
if (new_len > max_len || new_len == std::string::npos) break;
len = new_len;
}
assert(len + 0 < s.size());
assert(len + 1 < s.size());
//cut s, put cut part in vector
const std::string line = s.substr(0,len+1); //Keep space
assert(!line.empty());
v.push_back(line);
const std::size_t new_index = len+1; //After the space found
assert(new_index < s.size());
const std::string new_s = s.substr(new_index,s.size() - new_index);
assert(s != new_s);
s = new_s;
}
///Replace bell characters by spaces again
for (std::string& s: v)
{
assert(x != ' ');
std::size_t pos = s.find(x);
while (pos != std::string::npos)
{
assert(pos != std::string::npos);
assert(pos < s.size());
assert(pos == s.find(x)); //To prevent infinite while loop
s[pos] = ' ';
assert(s[pos] == ' ');
assert(pos != s.find(x)); //To prevent infinite while loop
pos = s.find(x);
}
assert(s.find(x) == std::string::npos);
}
#ifndef NDEBUG
//Test if Unwordwrap the result produces the original input
if (Unwordwrap(v) != s_original)
{
std::cerr << v.size() << '\n';
std::copy(v.begin(),v.end(),std::ostream_iterator<std::string>(std::cerr,"\n"));
std::cerr << Unwordwrap(v) << '\n';
std::cerr << s_original << std::endl;
}
#endif
assert(Unwordwrap(v) == s_original);
return v;
}
int main()
{
{
const std::string s = "123";
const std::vector<std::string> expected = { "123" };
const std::vector<std::string> v = Wordwrap(s,11);
assert(v == expected);
assert(Unwordwrap(v) == s);
}
{
const std::string s = "1234567890 123";
//Note that exected keeps trailing spaces at then end of a cut
const std::vector<std::string> expected = { "1234567890 ", "123" };
const std::vector<std::string> v = Wordwrap(s,11);
//if (v != expected)
//{
// const std::size_t sz = v.size();
// for (std::size_t i=0; i!=sz; ++i)
// {
// std::cout << i << '/' << sz << ": '" << v[i] << '\'' << std::endl;
// }
//}
assert(v == expected);
assert(Unwordwrap(v) == s);
}
{
const std::string s = "1234567890 123";
const std::vector<std::string> expected = { "1234567890 ", "123" };
const std::vector<std::string> v = Wordwrap(s,11);
//if (v != expected)
//{
// const std::size_t sz = v.size();
// for (std::size_t i=0; i!=sz; ++i)
// {
// std::cout << i << '/' << sz << ": '" << v[i] << '\'' << std::endl;
// }
//}
assert(v == expected);
assert(Unwordwrap(v) == s);
}
{
const std::string s = "123 567890 123";
const std::vector<std::string> expected = { "123 567890 ", "123" };
const std::vector<std::string> v = Wordwrap(s,11);
assert(v == expected);
assert(Unwordwrap(v) == s);
}
{
const auto v {
"",
"1",
"12",
"123",
"1234",
"12345",
"123456",
"1234567",
"12345678",
"123456789",
"1234567890",
"12345678901",
"123456789012",
"1234567890123",
"12345678901234",
"123456789012345",
"1234567890123456",
"12345678901234567",
"123456789012345678",
"1234567890123456789",
"12345678901234567890",
"123456789012345678901",
"1234567890123456789012",
"12345678901234567890123",
"123456789012345678901234",
"1234567890123456789012345",
"12345678901234567890123456",
"123456789012345678901234567",
"1234567890123456789012345678",
"12345678901234567890123456789",
"123456789012345678901234567890",
"1234567890123456789012345678901",
"12345678901234567890123456789012",
"123456789012345678901234567890123",
"1234567890123456789012345678901234",
"12345678901234567890123456789012345",
"123456789012345678901234567890123456",
"1234567890123456789012345678901234567",
"12345678901234567890123456789012345678",
"123456789012345678901234567890123456789",
"1234567890123456789012345678901234567890",
"1 1",
"12 12",
"123 123",
"1234 1234",
"12345 12345",
"123456 123456",
"1234567 1234567",
"12345678 8",
"123456789 9",
"1234567890 0",
"1234567890 1234567890",
"1234567890 1234567890 1234567890",
"1234567890 1234567890 1234567890 1234567890",
"1234567890 1234567890 1234567890 1234567890 1234567890",
"1234567890 1234567890 1234567890 1234567890 1234567890 1234567890",
"1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890",
"1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890",
"1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890",
"1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890",
"1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890",
"1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890",
"1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890",
"1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890 1234567890",
" 1",
" 1",
" 1 ",
" 1 ",
" 1 2 ",
" 1 23 ",
" 12 34 ",
" 12 34 ",
" 12 34 ",
" 12 34 5",
" 12 34 5 ",
" 12 34 5 6",
"0 12 34 5 6",
"0 12 34 5 6 ",
" ",
" ",
" ",
" ",
" ",
" ",
" "
};
for (int len=1; len!=1000; ++len)
{
for (const std::string& s: v)
{
//Wordwrap calls Unwordwrap
Wordwrap(s,len);
}
}
}
}
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Lubuntu 15.04 (vivid)
Qt Creator 3.1.1
STL: GNU ISO C++ Library, version 4.9.2
