ladybird/AK/StringUtils.cpp
Jesús "gsus" Lapastora 7578620f25 AK/StringUtils: Ensure needle positions don't overlap in replace
Previously, `replace` used `find_all` to find all of the positions to
replace. But `find_all` finds all the *overlapping* instances of the
needle, while `replace` assumed that the next position was always at
least `needle.length()` away from the last one. This led to crashes like
https://github.com/SerenityOS/jakt/issues/1159.
2023-12-17 12:00:48 -07:00

616 lines
19 KiB
C++

/*
* Copyright (c) 2018-2022, Andreas Kling <awesomekling@gmail.com>
* Copyright (c) 2020, Fei Wu <f.eiwu@yahoo.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/CharacterTypes.h>
#include <AK/MemMem.h>
#include <AK/Optional.h>
#include <AK/String.h>
#include <AK/StringBuilder.h>
#include <AK/StringUtils.h>
#include <AK/StringView.h>
#include <AK/Vector.h>
#ifdef KERNEL
# include <Kernel/Library/StdLib.h>
#else
# include <AK/ByteString.h>
# include <AK/FloatingPointStringConversions.h>
# include <string.h>
#endif
namespace AK {
namespace StringUtils {
bool matches(StringView str, StringView mask, CaseSensitivity case_sensitivity, Vector<MaskSpan>* match_spans)
{
auto record_span = [&match_spans](size_t start, size_t length) {
if (match_spans)
match_spans->append({ start, length });
};
if (str.is_null() || mask.is_null())
return str.is_null() && mask.is_null();
if (mask == "*"sv) {
record_span(0, str.length());
return true;
}
char const* string_ptr = str.characters_without_null_termination();
char const* string_start = str.characters_without_null_termination();
char const* string_end = string_ptr + str.length();
char const* mask_ptr = mask.characters_without_null_termination();
char const* mask_end = mask_ptr + mask.length();
while (string_ptr < string_end && mask_ptr < mask_end) {
auto string_start_ptr = string_ptr;
switch (*mask_ptr) {
case '*':
if (mask_ptr == mask_end - 1) {
record_span(string_ptr - string_start, string_end - string_ptr);
return true;
}
while (string_ptr < string_end && !matches({ string_ptr, static_cast<size_t>(string_end - string_ptr) }, { mask_ptr + 1, static_cast<size_t>(mask_end - mask_ptr - 1) }, case_sensitivity))
++string_ptr;
record_span(string_start_ptr - string_start, string_ptr - string_start_ptr);
--string_ptr;
break;
case '?':
record_span(string_ptr - string_start, 1);
break;
case '\\':
// if backslash is last character in mask, just treat it as an exact match
// otherwise use it as escape for next character
if (mask_ptr + 1 < mask_end)
++mask_ptr;
[[fallthrough]];
default:
auto p = *mask_ptr;
auto ch = *string_ptr;
if (case_sensitivity == CaseSensitivity::CaseSensitive ? p != ch : to_ascii_lowercase(p) != to_ascii_lowercase(ch))
return false;
break;
}
++string_ptr;
++mask_ptr;
}
if (string_ptr == string_end) {
// Allow ending '*' to contain nothing.
while (mask_ptr != mask_end && *mask_ptr == '*') {
record_span(string_ptr - string_start, 0);
++mask_ptr;
}
}
return string_ptr == string_end && mask_ptr == mask_end;
}
template<typename T>
Optional<T> convert_to_int(StringView str, TrimWhitespace trim_whitespace)
{
auto string = trim_whitespace == TrimWhitespace::Yes
? str.trim_whitespace()
: str;
if (string.is_empty())
return {};
T sign = 1;
size_t i = 0;
auto const characters = string.characters_without_null_termination();
if (characters[0] == '-' || characters[0] == '+') {
if (string.length() == 1)
return {};
i++;
if (characters[0] == '-')
sign = -1;
}
T value = 0;
for (; i < string.length(); i++) {
if (characters[i] < '0' || characters[i] > '9')
return {};
if (__builtin_mul_overflow(value, 10, &value))
return {};
if (__builtin_add_overflow(value, sign * (characters[i] - '0'), &value))
return {};
}
return value;
}
template Optional<i8> convert_to_int(StringView str, TrimWhitespace);
template Optional<i16> convert_to_int(StringView str, TrimWhitespace);
template Optional<i32> convert_to_int(StringView str, TrimWhitespace);
template Optional<long> convert_to_int(StringView str, TrimWhitespace);
template Optional<long long> convert_to_int(StringView str, TrimWhitespace);
template<typename T>
Optional<T> convert_to_uint(StringView str, TrimWhitespace trim_whitespace)
{
auto string = trim_whitespace == TrimWhitespace::Yes
? str.trim_whitespace()
: str;
if (string.is_empty())
return {};
T value = 0;
auto const characters = string.characters_without_null_termination();
for (size_t i = 0; i < string.length(); i++) {
if (characters[i] < '0' || characters[i] > '9')
return {};
if (__builtin_mul_overflow(value, 10, &value))
return {};
if (__builtin_add_overflow(value, characters[i] - '0', &value))
return {};
}
return value;
}
template Optional<u8> convert_to_uint(StringView str, TrimWhitespace);
template Optional<u16> convert_to_uint(StringView str, TrimWhitespace);
template Optional<u32> convert_to_uint(StringView str, TrimWhitespace);
template Optional<unsigned long> convert_to_uint(StringView str, TrimWhitespace);
template Optional<unsigned long long> convert_to_uint(StringView str, TrimWhitespace);
template<typename T>
Optional<T> convert_to_uint_from_hex(StringView str, TrimWhitespace trim_whitespace)
{
auto string = trim_whitespace == TrimWhitespace::Yes
? str.trim_whitespace()
: str;
if (string.is_empty())
return {};
T value = 0;
auto const count = string.length();
const T upper_bound = NumericLimits<T>::max();
for (size_t i = 0; i < count; i++) {
char digit = string[i];
u8 digit_val;
if (value > (upper_bound >> 4))
return {};
if (digit >= '0' && digit <= '9') {
digit_val = digit - '0';
} else if (digit >= 'a' && digit <= 'f') {
digit_val = 10 + (digit - 'a');
} else if (digit >= 'A' && digit <= 'F') {
digit_val = 10 + (digit - 'A');
} else {
return {};
}
value = (value << 4) + digit_val;
}
return value;
}
template Optional<u8> convert_to_uint_from_hex(StringView str, TrimWhitespace);
template Optional<u16> convert_to_uint_from_hex(StringView str, TrimWhitespace);
template Optional<u32> convert_to_uint_from_hex(StringView str, TrimWhitespace);
template Optional<u64> convert_to_uint_from_hex(StringView str, TrimWhitespace);
template<typename T>
Optional<T> convert_to_uint_from_octal(StringView str, TrimWhitespace trim_whitespace)
{
auto string = trim_whitespace == TrimWhitespace::Yes
? str.trim_whitespace()
: str;
if (string.is_empty())
return {};
T value = 0;
auto const count = string.length();
const T upper_bound = NumericLimits<T>::max();
for (size_t i = 0; i < count; i++) {
char digit = string[i];
u8 digit_val;
if (value > (upper_bound >> 3))
return {};
if (digit >= '0' && digit <= '7') {
digit_val = digit - '0';
} else {
return {};
}
value = (value << 3) + digit_val;
}
return value;
}
template Optional<u8> convert_to_uint_from_octal(StringView str, TrimWhitespace);
template Optional<u16> convert_to_uint_from_octal(StringView str, TrimWhitespace);
template Optional<u32> convert_to_uint_from_octal(StringView str, TrimWhitespace);
template Optional<u64> convert_to_uint_from_octal(StringView str, TrimWhitespace);
#ifndef KERNEL
template<typename T>
Optional<T> convert_to_floating_point(StringView str, TrimWhitespace trim_whitespace)
{
static_assert(IsSame<T, double> || IsSame<T, float>);
auto string = trim_whitespace == TrimWhitespace::Yes
? str.trim_whitespace()
: str;
char const* start = string.characters_without_null_termination();
return parse_floating_point_completely<T>(start, start + string.length());
}
template Optional<double> convert_to_floating_point(StringView str, TrimWhitespace);
template Optional<float> convert_to_floating_point(StringView str, TrimWhitespace);
#endif
bool equals_ignoring_ascii_case(StringView a, StringView b)
{
if (a.length() != b.length())
return false;
for (size_t i = 0; i < a.length(); ++i) {
if (to_ascii_lowercase(a.characters_without_null_termination()[i]) != to_ascii_lowercase(b.characters_without_null_termination()[i]))
return false;
}
return true;
}
bool ends_with(StringView str, StringView end, CaseSensitivity case_sensitivity)
{
if (end.is_empty())
return true;
if (str.is_empty())
return false;
if (end.length() > str.length())
return false;
if (case_sensitivity == CaseSensitivity::CaseSensitive)
return !memcmp(str.characters_without_null_termination() + (str.length() - end.length()), end.characters_without_null_termination(), end.length());
auto str_chars = str.characters_without_null_termination();
auto end_chars = end.characters_without_null_termination();
size_t si = str.length() - end.length();
for (size_t ei = 0; ei < end.length(); ++si, ++ei) {
if (to_ascii_lowercase(str_chars[si]) != to_ascii_lowercase(end_chars[ei]))
return false;
}
return true;
}
bool starts_with(StringView str, StringView start, CaseSensitivity case_sensitivity)
{
if (start.is_empty())
return true;
if (str.is_empty())
return false;
if (start.length() > str.length())
return false;
if (str.characters_without_null_termination() == start.characters_without_null_termination())
return true;
if (case_sensitivity == CaseSensitivity::CaseSensitive)
return !memcmp(str.characters_without_null_termination(), start.characters_without_null_termination(), start.length());
auto str_chars = str.characters_without_null_termination();
auto start_chars = start.characters_without_null_termination();
size_t si = 0;
for (size_t starti = 0; starti < start.length(); ++si, ++starti) {
if (to_ascii_lowercase(str_chars[si]) != to_ascii_lowercase(start_chars[starti]))
return false;
}
return true;
}
bool contains(StringView str, StringView needle, CaseSensitivity case_sensitivity)
{
if (str.is_null() || needle.is_null() || str.is_empty() || needle.length() > str.length())
return false;
if (needle.is_empty())
return true;
auto str_chars = str.characters_without_null_termination();
auto needle_chars = needle.characters_without_null_termination();
if (case_sensitivity == CaseSensitivity::CaseSensitive)
return memmem(str_chars, str.length(), needle_chars, needle.length()) != nullptr;
auto needle_first = to_ascii_lowercase(needle_chars[0]);
for (size_t si = 0; si < str.length(); si++) {
if (to_ascii_lowercase(str_chars[si]) != needle_first)
continue;
for (size_t ni = 0; si + ni < str.length(); ni++) {
if (to_ascii_lowercase(str_chars[si + ni]) != to_ascii_lowercase(needle_chars[ni])) {
if (ni > 0)
si += ni - 1;
break;
}
if (ni + 1 == needle.length())
return true;
}
}
return false;
}
bool is_whitespace(StringView str)
{
return all_of(str, is_ascii_space);
}
StringView trim(StringView str, StringView characters, TrimMode mode)
{
size_t substring_start = 0;
size_t substring_length = str.length();
if (mode == TrimMode::Left || mode == TrimMode::Both) {
for (size_t i = 0; i < str.length(); ++i) {
if (substring_length == 0)
return ""sv;
if (!characters.contains(str[i]))
break;
++substring_start;
--substring_length;
}
}
if (mode == TrimMode::Right || mode == TrimMode::Both) {
for (size_t i = str.length(); i > 0; --i) {
if (substring_length == 0)
return ""sv;
if (!characters.contains(str[i - 1]))
break;
--substring_length;
}
}
return str.substring_view(substring_start, substring_length);
}
StringView trim_whitespace(StringView str, TrimMode mode)
{
return trim(str, " \n\t\v\f\r"sv, mode);
}
Optional<size_t> find(StringView haystack, char needle, size_t start)
{
if (start >= haystack.length())
return {};
for (size_t i = start; i < haystack.length(); ++i) {
if (haystack[i] == needle)
return i;
}
return {};
}
Optional<size_t> find(StringView haystack, StringView needle, size_t start)
{
if (start > haystack.length())
return {};
auto index = AK::memmem_optional(
haystack.characters_without_null_termination() + start, haystack.length() - start,
needle.characters_without_null_termination(), needle.length());
return index.has_value() ? (*index + start) : index;
}
Optional<size_t> find_last(StringView haystack, char needle)
{
for (size_t i = haystack.length(); i > 0; --i) {
if (haystack[i - 1] == needle)
return i - 1;
}
return {};
}
Optional<size_t> find_last(StringView haystack, StringView needle)
{
for (size_t i = haystack.length(); i > 0; --i) {
auto value = StringUtils::find(haystack, needle, i - 1);
if (value.has_value())
return value;
}
return {};
}
Optional<size_t> find_last_not(StringView haystack, char needle)
{
for (size_t i = haystack.length(); i > 0; --i) {
if (haystack[i - 1] != needle)
return i - 1;
}
return {};
}
Vector<size_t> find_all(StringView haystack, StringView needle)
{
Vector<size_t> positions;
size_t current_position = 0;
while (current_position <= haystack.length()) {
auto maybe_position = AK::memmem_optional(
haystack.characters_without_null_termination() + current_position, haystack.length() - current_position,
needle.characters_without_null_termination(), needle.length());
if (!maybe_position.has_value())
break;
positions.append(current_position + *maybe_position);
current_position += *maybe_position + 1;
}
return positions;
}
Optional<size_t> find_any_of(StringView haystack, StringView needles, SearchDirection direction)
{
if (haystack.is_empty() || needles.is_empty())
return {};
if (direction == SearchDirection::Forward) {
for (size_t i = 0; i < haystack.length(); ++i) {
if (needles.contains(haystack[i]))
return i;
}
} else if (direction == SearchDirection::Backward) {
for (size_t i = haystack.length(); i > 0; --i) {
if (needles.contains(haystack[i - 1]))
return i - 1;
}
}
return {};
}
#ifndef KERNEL
ByteString to_snakecase(StringView str)
{
auto should_insert_underscore = [&](auto i, auto current_char) {
if (i == 0)
return false;
auto previous_ch = str[i - 1];
if (is_ascii_lower_alpha(previous_ch) && is_ascii_upper_alpha(current_char))
return true;
if (i >= str.length() - 1)
return false;
auto next_ch = str[i + 1];
if (is_ascii_upper_alpha(current_char) && is_ascii_lower_alpha(next_ch))
return true;
return false;
};
StringBuilder builder;
for (size_t i = 0; i < str.length(); ++i) {
auto ch = str[i];
if (should_insert_underscore(i, ch))
builder.append('_');
builder.append_as_lowercase(ch);
}
return builder.to_byte_string();
}
ByteString to_titlecase(StringView str)
{
StringBuilder builder;
bool next_is_upper = true;
for (auto ch : str) {
if (next_is_upper)
builder.append(to_ascii_uppercase(ch));
else
builder.append(to_ascii_lowercase(ch));
next_is_upper = ch == ' ';
}
return builder.to_byte_string();
}
ByteString invert_case(StringView str)
{
StringBuilder builder(str.length());
for (auto ch : str) {
if (is_ascii_lower_alpha(ch))
builder.append(to_ascii_uppercase(ch));
else
builder.append(to_ascii_lowercase(ch));
}
return builder.to_byte_string();
}
// Finishes the replacing algorithm once it is known that ita least one
// replacemnet is going to be done. Otherwise the caller may want to follow a
// different route to construct its output.
static StringBuilder replace_into_builder(StringView str, StringView needle, StringView replacement, ReplaceMode replace_mode, size_t first_replacement_position)
{
StringBuilder replaced_string;
replaced_string.append(str.substring_view(0, first_replacement_position));
replaced_string.append(replacement);
StringView remaining = str.substring_view(first_replacement_position + needle.length());
switch (replace_mode) {
case ReplaceMode::All:
while (!remaining.is_empty()) {
auto maybe_pos = remaining.find(needle);
if (!maybe_pos.has_value())
break;
replaced_string.append(remaining.substring_view(0, *maybe_pos));
replaced_string.append(replacement);
remaining = remaining.substring_view(*maybe_pos + needle.length());
}
break;
case ReplaceMode::FirstOnly:
// We already made the first replacement.
break;
}
// The remaining bits either don't contain the needle or are ignored due to
// `replace_mode` being `ReplaceMode::FirstOnly`.
replaced_string.append(remaining);
return replaced_string;
}
ByteString replace(StringView str, StringView needle, StringView replacement,
ReplaceMode replace_mode)
{
if (str.is_empty())
return str;
auto maybe_first = str.find(needle);
if (!maybe_first.has_value())
return str;
auto resulting_builder = replace_into_builder(str, needle, replacement, replace_mode, *maybe_first);
return resulting_builder.to_byte_string();
}
ErrorOr<String> replace(String const& haystack, StringView needle, StringView replacement, ReplaceMode replace_mode)
{
if (haystack.is_empty())
return haystack;
auto const source_bytes = haystack.bytes_as_string_view();
auto maybe_first = source_bytes.find(needle);
if (!maybe_first.has_value())
return haystack;
auto resulting_builder = replace_into_builder(source_bytes, needle, replacement, replace_mode, *maybe_first);
return resulting_builder.to_string();
}
#endif
// TODO: Benchmark against KMP (AK/MemMem.h) and switch over if it's faster for short strings too
size_t count(StringView str, StringView needle)
{
if (needle.is_empty())
return str.length();
size_t count = 0;
for (size_t i = 0; i < str.length() - needle.length() + 1; ++i) {
if (str.substring_view(i).starts_with(needle))
count++;
}
return count;
}
size_t count(StringView str, char needle)
{
size_t count = 0;
for (size_t i = 0; i < str.length(); ++i) {
if (str[i] == needle)
count++;
}
return count;
}
}
}