ladybird/AK/StringUtils.cpp
2021-12-21 13:13:04 -08:00

505 lines
16 KiB
C++

/*
* Copyright (c) 2018-2020, 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/Memory.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>
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;
}
const char* string_ptr = str.characters_without_null_termination();
const char* string_start = str.characters_without_null_termination();
const char* string_end = string_ptr + str.length();
const char* mask_ptr = mask.characters_without_null_termination();
const char* 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;
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;
const auto 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;
const auto 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 Optional<long> convert_to_uint(StringView str, TrimWhitespace);
template Optional<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;
const auto 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;
const auto 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);
bool equals_ignoring_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])) {
si += ni;
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 "";
if (!characters.contains(str[i]))
break;
++substring_start;
--substring_length;
}
}
if (mode == TrimMode::Right || mode == TrimMode::Both) {
for (size_t i = str.length() - 1; i > 0; --i) {
if (substring_length == 0)
return "";
if (!characters.contains(str[i]))
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", 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 {};
}
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 {};
}
String 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_string();
}
String to_titlecase(StringView str)
{
StringBuilder builder;
bool next_is_upper = true;
for (auto ch : str) {
if (next_is_upper)
builder.append_code_point(to_ascii_uppercase(ch));
else
builder.append_code_point(to_ascii_lowercase(ch));
next_is_upper = ch == ' ';
}
return builder.to_string();
}
String replace(StringView str, StringView needle, StringView replacement, bool all_occurrences)
{
if (str.is_empty())
return str;
Vector<size_t> positions;
if (all_occurrences) {
positions = str.find_all(needle);
if (!positions.size())
return str;
} else {
auto pos = str.find(needle);
if (!pos.has_value())
return str;
positions.append(pos.value());
}
StringBuilder replaced_string;
size_t last_position = 0;
for (auto& position : positions) {
replaced_string.append(str.substring_view(last_position, position - last_position));
replaced_string.append(replacement);
last_position = position + needle.length();
}
replaced_string.append(str.substring_view(last_position, str.length() - last_position));
return replaced_string.build();
}
// 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;
}
}
}