Module content_source 

Capability trait for the external references a decoded view resolves. What a reader is allowed to ask the outside world for.

Turning engine integers into typed semantics means reaching things that live outside the file being read: a 2DA row, a line of display text, whether a referenced resource is actually there. Taking a concrete resource-mounting type instead would drag that whole layer into every crate that only wanted to parse and resolve bytes.

ContentSource is that seam. It lives in rakata-formats because it returns a TwoDa, and formats is the lowest crate that can name one.

Nothing consumes it today

The decoded views were its caller and they have been removed, pending a consumer that can state requirements. What keeps the seam here rather than deleting it with them is the ruling it was built for: “no install” is a source that answers nothing, not a second code path through every reader. If the decoded layer has not been rebuilt by the time the write path lands, this goes then.

Capability is opt-in

Every method has a default body, so an implementor writes only the capabilities it has. A decode test hands in a map of tables and implements one method; an install-backed source implements all of them. A capability added here later breaks no implementor and no call site.

The defaults answer “I did not look”, never “no”. That distinction is the reason ContentSource::resource_exists returns Option<bool> rather than a bool: a source with no install behind it saying false is a negative claim from something that never went looking, and a caller cannot tell that apart from a real absence.

Shape

Every method takes &mut self, including the read-only ones. Mixing &self in buys nothing, because the borrow conflict callers hit comes from holding a returned table, and that blocks a shared borrow exactly as hard as a mutable one. Uniform &mut self leaves every capability free to populate itself lazily, which is what an install-backed talk table needs.

Only the table is returned borrowed. It is large and a resolver reads several cells out of one row, so the borrow earns itself. Strings are small and read once, and a second borrowing accessor would multiply the inner-block dance Uti’s magnitude resolution already needs across every view.

The trait is not object-safe, since the table lookup takes impl AsRef<str>. Call sites take &mut impl ContentSource, so nothing needs it to be.

Structs

NoSource

A source that answers nothing.

Traits

ContentSource

Something a reader can resolve external references against.