files

Read, write and edit files in the world's virtual filesystem.

The same bytes vfs.read and vfs.write reach, with the one thing a raw VFS call cannot express: durable. While play is running, an ordinary /source write lands on the play shadow — it reads back live, but it is discarded when play exits unless someone promotes it. A durable write says these bytes are the source: it goes to canonical /source with play still running and the session still in play, hot-reloading whatever reads it, with nothing left to promote and nobody's simulation stopped.

That is why these are tools rather than a thing every caller hand-rolls: the choice between "try this" and "this is the source" is the whole decision, and it should be one argument rather than a second call to vfs.promotePlayShadow that is easy to forget.