Import the "gerbert" kernel I worked on earlier this year.

It's a lot crappier than I remembered it. It's gonna need a lot of work.

Kernel/String.cpp

@@ -0,0 +1,86 @@
+#include "String.h"
+#include "StdLib.h"
+
+String::String()
+{
+}
+
+String::String(const char* characters)
+    : m_data(DataBuffer::copy((const BYTE*)characters, strlen(characters) + 1))
+{
+}
+
+String::String(const char* characters, size_t length)
+    : m_data(DataBuffer::createUninitialized(length + 1))
+{
+    memcpy(m_data->data(), characters, length);
+    m_data->data()[length] = '\0';
+}
+
+String::String(String&& other)
+    : m_data(move(other.m_data))
+{
+}
+
+String::String(const String& other)
+    : m_data(other.m_data)
+{
+}
+
+String& String::operator=(const String& other)
+{
+    if (this == &other)
+        return *this;
+    m_data = other.m_data;
+    return *this;
+}
+
+String& String::operator=(const String&& other)
+{
+    if (this == &other)
+        return *this;
+    m_data = move(other.m_data);
+    return *this;
+}
+
+String::~String()
+{
+}
+
+bool String::operator==(const String& other) const
+{
+    if (length() != other.length())
+        return false;
+    return strcmp(characters(), other.characters()) == 0;
+}
+
+String String::substring(size_t start, size_t length) const
+{
+    ASSERT(start + length <= m_data->length());
+    // FIXME: This needs some input bounds checking.
+    auto buffer = DataBuffer::createUninitialized(length + 1);
+    memcpy(buffer->data(), characters() + start, length);
+    buffer->data()[length] = '\0';
+    String s;
+    s.m_data = move(buffer);
+    return s;
+}
+
+Vector<String> String::split(char separator) const
+{
+    Vector<String> v;
+    size_t substart = 0;
+    for (size_t i = 0; i < length(); ++i) {
+        char ch = characters()[i];
+        if (ch == separator) {
+            size_t sublen = i - substart;
+            if (sublen != 0)
+                v.append(substring(substart, sublen));
+            substart = i + 1;
+        }
+    }
+    size_t taillen = length() - 1 - substart;
+    if (taillen != 0)
+        v.append(substring(substart, taillen));
+    return v;
+}