AK: Try to use StringViews more for substrings and splitting.

AK/StringView.cpp

@@ -0,0 +1,54 @@
+#include <AK/StringView.h>
+#include <AK/AKString.h>
+
+namespace AK {
+
+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().view());
+    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;
+}
+
+
+}