A new engineering proposal from developer yuer outlines a formal definition for quant operators in Rust, moving away from traditional function models. The document argues that pure functions struggle with indicators requiring persistent state, time sensitivity, or consistent semantics across batch and streaming data. This framework aims to solve those limitations with explicit execution boundaries.

Rust’s ownership model makes these limitations explicit, demanding clear state responsibility and rejecting implicit globals. The proposal defines an operator as a schedulable execution unit with defined input/output semantics that owns its state boundaries. Failures are treated as first-class results rather than panics, giving the caller control over whether a system halts.

A minimal reference implementation proves the concept, featuring a core `Operator` trait with an `execute` method that returns a `Result`. While the provided `Sum` struct is a trivial, stateless example, it validates the underlying definitions. The author intentionally excludes complex topics like state models or time semantics in this initial draft.

This work builds on yuer's background in EDCA OS and controllable AI standards. The proposal offers a foundational blueprint for developers building high-performance, stateful financial models in Rust. It sets the stage for more advanced execution semantics and error handling in future quant libraries.