Struct OperatorWriteOutput 

pub struct OperatorWriteOutput {
    pub write_prologue: TokenStream,
    pub write_prologue_after: 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. Important: When destructuring this struct in delegating operators, list all fields explicitly rather than using .. to ensure new fields are not silently dropped.

Fields

write_prologue: TokenStream

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

write_prologue_after: TokenStream

Code which runs once outside the subgraph, AFTER subgraphs are initialized, to set up state hooks which may need the subgraph ID.

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.

Trait Implementations

impl Default for OperatorWriteOutput

fn default() -> OperatorWriteOutput

Returns the “default value” for a type.