`collect_links()` imports private `_walk_links` from `block` module

[sumanjeet0012]

utils.py imports _walk_links (a private function) from block.py. This cross-module use of a private function is fragile and should be refactored.

Problem

In dag/utils.py:

def collect_links(value: Any) -> list[tuple[str, CID]]:
    from .block import _walk_links  # ← Imports private function

    return list(_walk_links(value, ""))

In dag/block.py:

def _walk_links(node: Any, prefix: str) -> Iterator[tuple[str, CID]]:
    """Recursively yield (path, cid) from an IPLD data-model value."""
    # ...

The _walk_links function is used by both Block.links() and collect_links(), but it's marked as private with the _ prefix.

Proposed Solution

Move _walk_links to utils.py and make it public:

# In dag/utils.py:
def walk_links(node: Any, prefix: str = "") -> Iterator[tuple[str, CID]]:
    """Recursively yield (path, cid) from an IPLD data-model value."""
    if is_cid(node):
        yield (prefix, node)
    elif isinstance(node, dict):
        for k, v in node.items():
            child = f"{prefix}/{k}" if prefix else k
            yield from walk_links(v, child)
    elif isinstance(node, list):
        for i, v in enumerate(node):
            child = f"{prefix}/{i}" if prefix else str(i)
            yield from walk_links(v, child)

def collect_links(value: Any) -> list[tuple[str, CID]]:
    return list(walk_links(value, ""))

Update block.py to import from utils.py:

from .utils import walk_links as _walk_links

Export walk_links from __init__.py.

Related

• Files: dag/utils.py, dag/block.py