# `Exgit.Workspace.VFS`
[🔗](https://github.com/ivarvong/exgit/blob/v0.1.0/lib/exgit/workspace/vfs.ex#L2)

`VFS.Mountable` defimpl for `Exgit.Workspace`.

Loaded only when `:vfs` is available — `Exgit.Workspace` is
fully usable without `:vfs` for direct API access. Mounting
a workspace into a `%VFS{}` mount table makes it interoperable
with other backends (in-memory scratch, postgres, S3) under one
tree.

    ws = Exgit.Workspace.open(repo, "main")
    fs = VFS.new() |> VFS.mount("/repo", ws)

    {:ok, content, fs} = VFS.read_file(fs, "/repo/lib/foo.ex")
    {:ok, fs} = VFS.write_file(fs, "/repo/lib/foo.ex", new_source)

The mount table threads workspace state through every op, so
cache growth from lazy fetches and `head_tree` advancement
from writes are both visible to subsequent calls.

## Capabilities

`[:read, :write, :lazy]`. We do not claim `:mkdir`: git trees
cannot represent empty directories, so a faithful `mkdir/3`
has no honest semantics. Writes implicitly create parents (vfs
explicitly supports this for flat-keyed backends).

## Mutations through vfs vs git-aware ops

File-shaped mutations (`write_file`, `rm`) flow through this
impl. Git-aware ops (`Exgit.Workspace.commit/2`,
`snapshot/1`, `restore/2`, `diff/1`, `checkout/2`) are not
part of `VFS.Mountable` — agents reach for them on the
workspace struct directly.

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*Consult [api-reference.md](api-reference.md) for complete listing*