Two-Stack Sliding-Window Aggregation
Summary
The article explains a two-stack sliding-window aggregation algorithm that generalizes to arbitrary associative aggregations using empty, unit, combine, and finalize. It demonstrates amortized O(1) time per operation with O(w) memory, includes code examples in Python and Rust-like signatures, and discusses floating-point non-invertibility and non-associativity considerations. The piece also contextualizes its relation to existing literature and provides a practical visualization of the mechanism.