ladybird/AK/StringView.cpp
Sergey Bugaev 1a697f70db AK: Add more StringView utilities for making substrings.
These two allow making a new substring view starting from,
or starting after, an existing substring view.

Also make use of one of them in the kernel.
2019-06-14 06:24:02 +02:00

79 lines
2.2 KiB
C++

#include <AK/AKString.h>
#include <AK/StringView.h>
namespace AK {
StringView::StringView(const String& string)
: m_impl(string.impl())
, 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 };
}
StringView StringView::substring_view_starting_from_substring(const StringView& substring) const
{
const char* remaining_characters = substring.characters();
ASSERT(remaining_characters >= m_characters);
ASSERT(remaining_characters <= m_characters + m_length);
int remaining_length = m_length - (remaining_characters - m_characters);
return { remaining_characters, remaining_length };
}
StringView StringView::substring_view_starting_after_substring(const StringView& substring) const
{
const char* remaining_characters = substring.characters() + substring.length();
ASSERT(remaining_characters >= m_characters);
ASSERT(remaining_characters <= m_characters + m_length);
int remaining_length = m_length - (remaining_characters - m_characters);
return { remaining_characters, remaining_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;
}
}