home/src/string_utils.cc
Maxime Coste 2f48bbf6ff Tweak unescape template function to unescape the escape char as well
Test that more thouroughly in the unit tests.
2017-12-07 01:56:02 +08:00

382 lines
10 KiB
C++

#include "string_utils.hh"
#include "exception.hh"
#include "utf8_iterator.hh"
#include "unit_tests.hh"
namespace Kakoune
{
StringView trim_whitespaces(StringView str)
{
auto beg = str.begin(), end = str.end();
while (beg != end and is_blank(*beg))
++beg;
while (beg != end and is_blank(*(end-1)))
--end;
return {beg, end};
}
String escape(StringView str, StringView characters, char escape)
{
String res;
res.reserve(str.length());
auto cbeg = characters.begin(), cend = characters.end();
for (auto it = str.begin(), end = str.end(); it != end; )
{
auto next = std::find_first_of(it, end, cbeg, cend);
if (next != end)
{
res += StringView{it, next+1};
res.back() = escape;
res += *next;
it = next+1;
}
else
{
res += StringView{it, next};
break;
}
}
return res;
}
String unescape(StringView str, StringView characters, char escape)
{
String res;
res.reserve(str.length());
for (auto it = str.begin(), end = str.end(); it != end; )
{
auto next = std::find(it, end, escape);
if (next != end and next+1 != end and contains(characters, *(next+1)))
{
res += StringView{it, next+1};
res.back() = *(next+1);
it = next + 2;
}
else
{
res += StringView{it, next == end ? next : next + 1};
it = next == end ? next : next + 1;
}
}
return res;
}
String indent(StringView str, StringView indent)
{
String res;
res.reserve(str.length());
bool was_eol = true;
for (ByteCount i = 0; i < str.length(); ++i)
{
if (was_eol)
res += indent;
res += str[i];
was_eol = is_eol(str[i]);
}
return res;
}
String replace(StringView str, StringView substr, StringView replacement)
{
String res;
for (auto it = str.begin(); it != str.end(); )
{
auto match = std::search(it, str.end(), substr.begin(), substr.end());
res += StringView{it, match};
if (match == str.end())
break;
res += replacement;
it = match + (int)substr.length();
}
return res;
}
Optional<int> str_to_int_ifp(StringView str)
{
bool negative = not str.empty() and str[0] == '-';
if (negative)
str = str.substr(1_byte);
unsigned int res = 0;
for (auto c : str)
{
if (c < '0' or c > '9')
return {};
res = res * 10 + c - '0';
}
return negative ? -res : res;
}
int str_to_int(StringView str)
{
if (auto val = str_to_int_ifp(str))
return *val;
throw runtime_error{str + " is not a number"};
}
InplaceString<15> to_string(int val)
{
InplaceString<15> res;
res.m_length = sprintf(res.m_data, "%i", val);
return res;
}
InplaceString<23> to_string(long int val)
{
InplaceString<23> res;
res.m_length = sprintf(res.m_data, "%li", val);
return res;
}
InplaceString<23> to_string(long long int val)
{
InplaceString<23> res;
res.m_length = sprintf(res.m_data, "%lli", val);
return res;
}
InplaceString<23> to_string(size_t val)
{
InplaceString<23> res;
res.m_length = sprintf(res.m_data, "%zu", val);
return res;
}
InplaceString<23> to_string(Hex val)
{
InplaceString<23> res;
res.m_length = sprintf(res.m_data, "%zx", val.val);
return res;
}
InplaceString<23> to_string(float val)
{
InplaceString<23> res;
res.m_length = sprintf(res.m_data, "%f", val);
return res;
}
InplaceString<7> to_string(Codepoint c)
{
InplaceString<7> res;
char* ptr = res.m_data;
utf8::dump(ptr, c);
res.m_length = (int)(ptr - res.m_data);
return res;
}
bool subsequence_match(StringView str, StringView subseq)
{
auto it = str.begin();
for (auto& c : subseq)
{
if (it == str.end())
return false;
while (*it != c)
{
if (++it == str.end())
return false;
}
++it;
}
return true;
}
String expand_tabs(StringView line, ColumnCount tabstop, ColumnCount col)
{
String res;
res.reserve(line.length());
for (auto it = line.begin(), end = line.end(); it != end; )
{
if (*it == '\t')
{
ColumnCount end_col = (col / tabstop + 1) * tabstop;
res += String{' ', end_col - col};
col = end_col;
++it;
}
else
{
auto char_beg = it;
auto cp = utf8::read_codepoint(it, end);
res += {char_beg, it};
col += codepoint_width(cp);
}
}
return res;
}
Vector<StringView> wrap_lines(StringView text, ColumnCount max_width)
{
if (max_width <= 0)
throw runtime_error("Invalid max width");
using Utf8It = utf8::iterator<const char*>;
Utf8It it{text.begin(), text};
Utf8It end{text.end(), text};
Utf8It line_begin = it;
Utf8It last_word_end = it;
Vector<StringView> lines;
while (it != end)
{
const CharCategories cat = categorize(*it, {});
if (cat == CharCategories::EndOfLine)
{
lines.emplace_back(line_begin.base(), it.base());
line_begin = it = it+1;
continue;
}
Utf8It word_end = it+1;
while (word_end != end and categorize(*word_end, {}) == cat)
++word_end;
while (word_end > line_begin and
utf8::column_distance(line_begin.base(), word_end.base()) >= max_width)
{
auto line_end = last_word_end <= line_begin ?
Utf8It{utf8::advance(line_begin.base(), text.end(), max_width), text}
: last_word_end;
lines.emplace_back(line_begin.base(), line_end.base());
while (line_end != end and is_horizontal_blank(*line_end))
++line_end;
if (line_end != end and *line_end == '\n')
++line_end;
it = line_begin = line_end;
}
if (cat == CharCategories::Word or cat == CharCategories::Punctuation)
last_word_end = word_end;
if (word_end > line_begin)
it = word_end;
}
if (line_begin != end)
lines.emplace_back(line_begin.base(), text.end());
return lines;
}
template<typename AppendFunc>
void format_impl(StringView fmt, ArrayView<const StringView> params, AppendFunc append)
{
int implicitIndex = 0;
for (auto it = fmt.begin(), end = fmt.end(); it != end;)
{
auto opening = std::find(it, end, '{');
if (opening == end)
{
append(StringView{it, opening});
break;
}
else if (opening != it and *(opening-1) == '\\')
{
append(StringView{it, opening-1});
append('{');
it = opening + 1;
}
else
{
append(StringView{it, opening});
auto closing = std::find(opening, end, '}');
if (closing == end)
throw runtime_error("Format string error, unclosed '{'");
const int index = (closing == opening + 1) ?
implicitIndex : str_to_int({opening+1, closing});
if (index >= params.size())
throw runtime_error("Format string parameter index too big");
append(params[index]);
implicitIndex = index+1;
it = closing+1;
}
}
}
StringView format_to(ArrayView<char> buffer, StringView fmt, ArrayView<const StringView> params)
{
char* ptr = buffer.begin();
const char* end = buffer.end();
format_impl(fmt, params, [&](StringView s) mutable {
for (auto c : s)
{
if (ptr == end)
throw runtime_error("buffer is too small");
*ptr++ = c;
}
});
if (ptr == end)
throw runtime_error("buffer is too small");
*ptr = 0;
return { buffer.begin(), ptr };
}
String format(StringView fmt, ArrayView<const StringView> params)
{
ByteCount size = fmt.length();
for (auto& s : params) size += s.length();
String res;
res.reserve(size);
format_impl(fmt, params, [&](StringView s) { res += s; });
return res;
}
UnitTest test_string{[]()
{
kak_assert(String("youpi ") + "matin" == "youpi matin");
Vector<StringView> wrapped = wrap_lines("wrap this paragraph\n respecting whitespaces and much_too_long_words", 16);
kak_assert(wrapped.size() == 6);
kak_assert(wrapped[0] == "wrap this");
kak_assert(wrapped[1] == "paragraph");
kak_assert(wrapped[2] == " respecting");
kak_assert(wrapped[3] == "whitespaces and");
kak_assert(wrapped[4] == "much_too_long_wo");
kak_assert(wrapped[5] == "rds");
Vector<StringView> wrapped2 = wrap_lines("error: unknown type", 7);
kak_assert(wrapped2.size() == 3);
kak_assert(wrapped2[0] == "error:");
kak_assert(wrapped2[1] == "unknown");
kak_assert(wrapped2[2] == "type");
kak_assert(escape(R"(\youpi:matin:tchou\:)", ":\\", '\\') == R"(\\youpi\:matin\:tchou\\\:)");
kak_assert(unescape(R"(\\youpi\:matin\:tchou\\\:)", ":\\", '\\') == R"(\youpi:matin:tchou\:)");
kak_assert(prefix_match("tchou kanaky", "tchou"));
kak_assert(prefix_match("tchou kanaky", "tchou kanaky"));
kak_assert(prefix_match("tchou kanaky", "t"));
kak_assert(not prefix_match("tchou kanaky", "c"));
kak_assert(subsequence_match("tchou kanaky", "tknky"));
kak_assert(subsequence_match("tchou kanaky", "knk"));
kak_assert(subsequence_match("tchou kanaky", "tchou kanaky"));
kak_assert(not subsequence_match("tchou kanaky", "tchou kanaky"));
kak_assert(format("Youhou {1} {} {0} \\{}", 10, "hehe", 5) == "Youhou hehe 5 10 {}");
char buffer[20];
kak_assert(format_to(buffer, "Hey {}", 15) == "Hey 15");
kak_assert(str_to_int("5") == 5);
kak_assert(str_to_int(to_string(INT_MAX)) == INT_MAX);
kak_assert(str_to_int(to_string(INT_MIN)) == INT_MIN);
kak_assert(str_to_int("00") == 0);
kak_assert(str_to_int("-0") == 0);
kak_assert(replace("tchou/tcha/tchi", "/", "!!") == "tchou!!tcha!!tchi");
}};
}