loom tangle

Output is ordinary source. Tangling leaves no marker, no header and no import behind, so a file Loom wrote is indistinguishable from one a person typed. That is deliberate: a tool that stamped its output would make every consumer of that output care about the tool.

A file is only rewritten when its content would change. Prose edits therefore cost nothing downstream — no timestamp churn, and no rebuild triggered in whatever is watching the output directory.

Tangle checks the corpus before it writes anything, and it refuses the whole run rather than write half of it. An anchor that names a section which does not exist is the common case:

loom: refusing to tangle — Unresolved anchor: no section named `the parser`.

Refusing wholesale is what keeps a corpus and its files from drifting apart. A partial write would leave the output in a state no document describes.

--watch re-tangles when a document changes.

This is the normal way to work: leave it running beside the editor and the files follow the document as you write it.

Rename a section's sink and the file it used to write stays on disk, no longer described by anything. loom orphans lists those.

With --prune it deletes them. Without it, it only reports — which is the safer habit, since the list is also a useful signal that a rename went further than you intended.