Struct OperatorWriteOutput 

pub struct OperatorWriteOutput {
    pub write_prologue: TokenStream,
    pub write_iterator: TokenStream,
    pub write_iterator_after: TokenStream,
    pub write_tick_end: TokenStream,
}

The code generated and returned by a OperatorConstraints::write_fn.

This type intentionally does not implement Default. Constructing it with .. or ..Default::default() silently drops newly added fields (this once dropped write_tick_end from lattice_reduce). List every field explicitly when constructing or destructuring.

Fields

write_prologue: TokenStream

Code which runs once outside any subgraphs to set up external state (channels, network connections, etc.) to be used by the subgraph.

write_iterator: TokenStream

Iterator (or pusherator) code inside the subgraphs. The code for each operator is emitted in order.

Emitted code should assign to WriteContextArgs::ident and use WriteContextArgs::inputs (pull Streams) or WriteContextArgs::outputs (push Sinks).

write_iterator_after: TokenStream

Code which runs after Streams/Sinks have been run. Mainly for flushing IO.

write_tick_end: TokenStream

Code which runs at the end of each tick, after all subgraphs have run. Used for resetting state with 'tick persistence.