kakoune/src/string_utils.cc
Maxime Coste 8566ae14a0 Reduce the amount of Regex VM Instruction code
Merge all lookarounds into the same instruction, merge splits, merge
literal ignore case with literal...

Besides reducing the amount of almost duplicated code, this improves
performance by reducing pressure on the (often failing) branch target
prediction for instruction dispatching by moving branches into the
instruction code themselves where they are more likely to be well
predicted.
2021-11-21 09:44:18 +11:00

453 lines
12 KiB
C++

#include "string_utils.hh"
#include "exception.hh"
#include "utf8_iterator.hh"
#include "unit_tests.hh"
#include <cstdio>
namespace Kakoune
{
String trim_indent(StringView str)
{
if (str.empty())
return {};
if (str[0_byte] == '\n')
str = str.substr(1_byte);
while (not str.empty() and is_blank(str.back()))
str = str.substr(0, str.length() - 1);
utf8::iterator it{str.begin(), str};
while (it != str.end() and is_horizontal_blank(*it))
++it;
const StringView indent{str.begin(), it.base()};
return accumulate(str | split_after<StringView>('\n') | transform([&](auto&& line) {
if (line == "\n")
return line;
else if (not prefix_match(line, indent))
throw runtime_error("inconsistent indentation in the string");
return line.substr(indent.length());
}), String{}, [](String s, StringView l) { return s += l; });
}
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;
}
String left_pad(StringView str, ColumnCount size, Codepoint c)
{
return String(c, std::max(0_col, size - str.column_length())) + str.substr(0, size);
}
String right_pad(StringView str, ColumnCount size, Codepoint c)
{
return str.substr(0, size) + String(c, std::max(0_col, size - str.column_length()));
}
Optional<int> str_to_int_ifp(StringView str)
{
bool negative = not str.empty() and str[0] == '-';
if (negative)
str = str.substr(1_byte);
if (str.empty())
return {};
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<15> to_string(unsigned val)
{
InplaceString<15> res;
res.m_length = sprintf(res.m_data, "%u", 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(unsigned long val)
{
InplaceString<23> res;
res.m_length = sprintf(res.m_data, "%lu", 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;
}
WrapView::Iterator::Iterator(StringView text, ColumnCount max_width)
: m_remaining{text}, m_max_width{max_width}
{
if (max_width <= 0)
throw runtime_error("Invalid max width");
++*this;
}
WrapView::Iterator& WrapView::Iterator::operator++()
{
using Utf8It = utf8::iterator<const char*>;
Utf8It it{m_remaining.begin(), m_remaining};
Utf8It last_word_end = it;
while (it != m_remaining.end())
{
const CharCategories cat = categorize(*it, {'_'});
if (cat == CharCategories::EndOfLine)
{
m_current = StringView{m_remaining.begin(), it.base()};
m_remaining = StringView{(it+1).base(), m_remaining.end()};
return *this;
}
Utf8It word_end = it+1;
while (word_end != m_remaining.end() and categorize(*word_end, {'_'}) == cat)
++word_end;
if (word_end > m_remaining.begin() and
utf8::column_distance(m_remaining.begin(), word_end.base()) >= m_max_width)
{
auto line_end = last_word_end <= m_remaining.begin() ?
Utf8It{utf8::advance(m_remaining.begin(), m_remaining.end(), m_max_width), m_remaining}
: last_word_end;
m_current = StringView{m_remaining.begin(), line_end.base()};
while (line_end != m_remaining.end() and is_horizontal_blank(*line_end))
++line_end;
if (line_end != m_remaining.end() and *line_end == '\n')
++line_end;
m_remaining = StringView{line_end.base(), m_remaining.end()};
return *this;
}
if (cat == CharCategories::Word or cat == CharCategories::Punctuation)
last_word_end = word_end;
if (word_end > m_remaining.begin())
it = word_end;
}
m_current = m_remaining;
m_remaining = StringView{};
return *this;
}
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 };
}
void format_with(FunctionRef<void (StringView)> append, StringView fmt, ArrayView<const StringView> params)
{
format_impl(fmt, params, append);
}
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;
}
String double_up(StringView s, StringView characters)
{
String res;
auto pos = s.begin();
for (auto it = s.begin(), end = s.end(); it != end; ++it)
{
if (contains(characters, *it))
{
res += StringView{pos, it+1};
res += *it;
pos = it+1;
}
}
res += StringView{pos, s.end()};
return res;
}
UnitTest test_string{[]()
{
kak_assert(String("youpi ") + "matin" == "youpi matin");
auto wrapped = "wrap this paragraph\n respecting whitespaces and much_too_long_words" | wrap_at(16) | gather<Vector>();
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");
auto wrapped2 = "error: unknown type" | wrap_at(7) | gather<Vector>();
kak_assert(wrapped2.size() == 3);
kak_assert(wrapped2[0] == "error:");
kak_assert(wrapped2[1] == "unknown");
kak_assert(wrapped2[2] == "type");
kak_assert(trim_indent(" ") == "");
kak_assert(trim_indent("no-indent") == "no-indent");
kak_assert(trim_indent("\nno-indent") == "no-indent");
kak_assert(trim_indent("\n indent\n indent") == "indent\nindent");
kak_assert(trim_indent("\n indent\n indent") == "indent\n indent");
kak_assert(trim_indent("\n indent\n indent\n ") == "indent\nindent");
kak_expect_throw(runtime_error, trim_indent("\n indent\nno-indent"));
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(double_up(R"('foo%"bar"')", "'\"%") == R"(''foo%%""bar""'')");
kak_assert(replace("tchou/tcha/tchi", "/", "!!") == "tchou!!tcha!!tchi");
}};
}