format: Query / display coroutine properties and state.

In crowding/generators: Coroutines: Generators / Yield, Async / Await, and Streams

Query / display coroutine properties and state.

Description

The coroutine format method displays its source code, its effective environment, whether it is running or finished, and a label indicating its last known state. The summary method returns the same information in a list.

summary(obj) returns a list with information on a coroutine's state, including:

• code: the expression used to create the coroutine;

• state: the current state (see below);

• node: is a character string that identifies a location in the coroutine source code; for example, a typical state string might be ".{.<-2.await__then", which can be read like "in the first argument of ⁠\{⁠, in the second argument of ⁠<-⁠, in a call to await(), at internal node then.";

• envir: the environment where the coroutine is evaluating R expressions;

• err: the error object, if the coroutine caught an error.

summary(g)$state for a generator g might be "yielded", "running" (if nextElem is currently being called,) "stopped" (for generators that have stopped with an error,) or "finished" (for generators that have finished normally.)

summary(a)$state of an async might be "pending", "resolved" or "rejected".

summary(s)$state on a stream might be "resolved", "rejected", "running", "woken", "yielding", or "yielded".

Usage

## S3 method for class 'coroutine'
format(x, ...)

## S3 method for class 'coroutine'
summary(object, ...)

## S3 method for class 'generator'
summary(object, ...)

## S3 method for class 'async'
summary(object, ...)

## S3 method for class 'stream'
summary(object, ...)

Arguments

x	A coroutine.
...	Undocumented.
object	a coroutine (async, generator, or stream) object.

crowding/generators documentation built on June 28, 2023, 6:14 a.m.