Major refractor

- Add regex search and replace
- Add chunk iterator + update line iterator.
- Cleanup/formatting.

src/vase/iterators/line.cc

@@ -0,0 +1,33 @@
+#include "vase/iterators/line.h"
+
+LineIterator::LineIterator(Shard *r, uint32_t start_line)
+    : offset(offset_of(r, start_line, 0)), it(r, offset) {}
+
+LineIterator::~LineIterator() {};
+
+bool LineIterator::next(std::string &line) {
+  line.clear();
+  while (true) {
+    if (remaining == 0) {
+      uint32_t got;
+      if (!it.next(&cursor, &got)) {
+        eof = true;
+        break;
+      }
+      remaining = got;
+    }
+    const char *nl = (const char *)memchr(cursor, '\n', remaining);
+    if (nl) {
+      const char *end = nl;
+      size_t len = end - cursor;
+      line.append(cursor, len);
+      cursor = end + 1;
+      remaining -= (uint32_t)(len + 1);
+      return true;
+    }
+    line.append(cursor, remaining);
+    cursor += remaining;
+    remaining = 0;
+  }
+  return !line.empty();
+}