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AK: Make String::matches() capable of reporting match positions too

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Also, rewrite StringUtils::match(), because the old implementation was
fairly broken, e.g. "acdcxb" would *not* match "a*?b".
This commit is contained in:
AnotherTest 2020-10-25 09:04:39 +03:30 • committed by Andreas Kling
parent 2d6d1ca67f
commit 0801b1fada
7 changed files with 86 additions and 33 deletions
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72
AK/StringUtils.cpp
View file

@ -30,62 +30,70 @@
#include <AK/String.h>
#include <AK/StringUtils.h>
#include <AK/StringView.h>
#include <AK/Vector.h>
namespace AK {
namespace StringUtils {
bool matches(const StringView& str, const StringView& mask, CaseSensitivity case_sensitivity)
bool matches(const StringView& str, const 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 == "*") {
record_span(0, str.length());
return true;
}
if (case_sensitivity == CaseSensitivity::CaseInsensitive) {
const String str_lower = String(str).to_lowercase();
const String mask_lower = String(mask).to_lowercase();
return matches(str_lower, mask_lower, CaseSensitivity::CaseSensitive);
return matches(str_lower, mask_lower, CaseSensitivity::CaseSensitive, match_spans);
}
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();
// Match string against mask directly unless we hit a *
while ((string_ptr < string_end) && (mask_ptr < mask_end) && (*mask_ptr != '*')) {
if ((*mask_ptr != *string_ptr) && (*mask_ptr != '?'))
return false;
mask_ptr++;
string_ptr++;
}
const char* cp = nullptr;
const char* mp = nullptr;
while (string_ptr < string_end) {
if ((mask_ptr < mask_end) && (*mask_ptr == '*')) {
// If we have only a * left, there is no way to not match.
if (++mask_ptr == mask_end)
auto matches_one = [](char ch, char p) {
if (p == '?')
return true;
return p == ch && ch != 0;
};
while (string_ptr < string_end && mask_ptr < mask_end) {
auto string_start_ptr = string_ptr;
switch (*mask_ptr) {
case '*':
if (mask_ptr[1] == 0) {
record_span(string_ptr - string_start, string_end - string_ptr);
return true;
mp = mask_ptr;
cp = string_ptr + 1;
} else if ((mask_ptr < mask_end) && ((*mask_ptr == *string_ptr) || (*mask_ptr == '?'))) {
mask_ptr++;
string_ptr++;
} else if ((cp != nullptr) && (mp != nullptr)) {
mask_ptr = mp;
string_ptr = cp++;
} else {
}
while (string_ptr < string_end && !matches(string_ptr, mask_ptr + 1))
++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:
if (!matches_one(*string_ptr, *mask_ptr))
return false;
break;
}
++string_ptr;
++mask_ptr;
}
// Handle any trailing mask
while ((mask_ptr < mask_end) && (*mask_ptr == '*'))
mask_ptr++;
// If we 'ate' all of the mask and the string then we match.
return (mask_ptr == mask_end) && string_ptr == string_end;
return string_ptr == string_end && mask_ptr == mask_end;
}
Optional<int> convert_to_int(const StringView& str)