ladybird/AK/StringView.cpp
Robin Burchell f9ba7adae2 StringView: Make construction of String from a StringView containing a String cheaper
... at the cost of an additional pointer per view.
2019-06-03 20:27:05 +02:00

60 lines
1.4 KiB
C++

#include <AK/AKString.h>
#include <AK/StringView.h>
namespace AK {
StringView::StringView(const AK::String& string)
: m_string(&string)
, m_characters(string.characters())
, m_length(string.length())
{
}
Vector<StringView> StringView::split_view(const char separator) const
{
if (is_empty())
return {};
Vector<StringView> v;
ssize_t substart = 0;
for (ssize_t i = 0; i < length(); ++i) {
char ch = characters()[i];
if (ch == separator) {
ssize_t sublen = i - substart;
if (sublen != 0)
v.append(substring_view(substart, sublen));
substart = i + 1;
}
}
ssize_t taillen = length() - substart;
if (taillen != 0)
v.append(substring_view(substart, taillen));
if (characters()[length() - 1] == separator)
v.append(String::empty());
return v;
}
StringView StringView::substring_view(int start, int length) const
{
if (!length)
return {};
ASSERT(start + length <= m_length);
return { m_characters + start, length };
}
unsigned StringView::to_uint(bool& ok) const
{
unsigned value = 0;
for (ssize_t i = 0; i < length(); ++i) {
if (characters()[i] < '0' || characters()[i] > '9') {
ok = false;
return 0;
}
value = value * 10;
value += characters()[i] - '0';
}
ok = true;
return value;
}
}