Major refractor

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

src/vase/iterators/chunk.cc

@@ -0,0 +1,75 @@
+#include "vase/iterators/chunk.h"
+
+ChunkIterator::ChunkIterator(Shard *r, uint32_t offset) : root(r) {
+  if (!root)
+    return;
+  Shard::retain(root);
+  seek(offset);
+}
+
+ChunkIterator::~ChunkIterator() {
+  Shard::release(root);
+}
+
+void ChunkIterator::seek(uint32_t offset) {
+  stack.clear();
+  petal = nullptr;
+  petal_offset = 0;
+  if (!root || offset >= root->length)
+    return;
+
+  uint32_t target = offset;
+  Shard *curr = root;
+
+  while (curr) {
+    if (curr->kind == Shard::ShardKind::Petal) {
+      petal = (Petal *)curr;
+      petal_offset = target;
+      return;
+    } else {
+      auto *b = (Branch *)curr;
+      uint32_t left_len = b->left->length;
+      if (target < left_len) {
+        stack.push_back(b->right);
+        curr = b->left;
+      } else {
+        target -= left_len;
+        curr = b->right;
+      }
+    }
+  }
+}
+
+bool ChunkIterator::next(const char **data, uint32_t *out_len) {
+  while (true) {
+    if (petal && petal_offset < petal->length) {
+      uint32_t remaining = petal->length - petal_offset;
+      uint32_t read_pos = petal->pos + petal_offset;
+      uint32_t got = 0;
+      const char *chunk = petal->source->read(read_pos, &got);
+      if (got == 0) {
+        petal = nullptr;
+        continue;
+      }
+      uint32_t take = std::min(got, remaining);
+      *data = chunk;
+      *out_len = take;
+      petal_offset += take;
+      return true;
+    }
+    if (stack.empty())
+      return false;
+    Shard *s = stack.back();
+    stack.pop_back();
+    if (!s)
+      continue;
+    if (s->kind == Shard::ShardKind::Petal) {
+      petal = (Petal *)s;
+      petal_offset = 0;
+    } else {
+      auto *b = (Branch *)s;
+      stack.push_back(b->right);
+      stack.push_back(b->left);
+    }
+  }
+}