Represents a partial or incremental update (delta) of a [Part].

This type enables composable, streaming updates to message parts. For example, text may be produced token-by-token, or a function call may be emitted gradually as its arguments stream in.

Example

Rust

let d1 = PartDelta::Text { text: \"Hel\".into() };
let d2 = PartDelta::Text { text: \"lo\".into() };
let merged = d1.accumulate(d2).unwrap();
assert_eq!(merged.to_text().unwrap(), \"Hello\");
Copy

Error Handling

Accumulation or finalization may return an error if incompatible deltas (e.g. mismatched function IDs) are combined or invalid JSON arguments are given.