Coding NestFlow: Fluent Box-Scoped JavaScript and Wasm

The engine in browsers is fast becoming the universal virtual machine for apps; and its coding is steadily evolving toward transparency and efficiency. To advance further toward those two goals is the aim of NestFlow. It is currently implemented in JavaScript–but clunkily owing to historical infelicities–so it is intended to eventually be implemented mostly in Wasm. That idiom is widely hoped and expected to become the universal low-level bytecode for browsers.