Crate lazy_async_promise

Primitives for combining tokio and immediate mode guis

List of primitives

The following primitives are implemented:

• ImmediateValuePromise: An immediately updating async-enabled single value promise
• ProgressTrackedImValProm: A progress/status emitting enhanced wrapper for ImmediateValuePromise
• LazyVecPromise: A lazily evaluated, partially readable and async-enabled vector-backed promise
• LazyValuePromise: A lazily evaluated and async-enabled single value promise

See these items for their respective documentation.

What to use

A general usage guide would be:

• You just want one value when ready? Use: ImmediateValuePromise (for laziness wrap in Option)
• If you need status update support for that, use ProgressTrackedImValProm
• You want several items of the same kind / streamed? Use: LazyVecPromise
• You want one item when ready and need lazy evaluation or have intermediate results? Use: LazyValuePromise

Modules

• api_macros
  Use this to get all macros

Macros

• send_data
  Send new data via the sender
• set_error
  Setting the given progress using a given sender.
• set_finished
  Set state to DataState::UpToDate
• set_progress
  Setting the given progress using a given sender.
• unpack_result
  Error checking in async updater functions is tedious - this helps out by resolving results and sending errors on error. Result will be unwrapped if no error occurs.

Structs

• BoxedSendError
  Strong type to keep the boxed error. You can just deref it to get the inside box.
• ImmediateValuePromise
  A promise which can be easily created and stored.
• LazyValuePromise
  A single lazy-async updated value
• LazyVecPromise
  A lazy, async and partially readable vector promise
• Progress
  a f64 type which is constrained to the range of 0.0 and 1.0
• ProgressTrackedImValProm
  A progress and status enabling wrapper for ImmediateValuePromise
• Status
  A status update struct containing the issue-date, progress and a message You can use any struct that can be transferred via tokio mpsc channels.

Enums

• DataState
  Represents a processing state.
• ImmediateValueState
  The return state of a ImmediateValuePromise, contains the error, the value or that it is still updating
• Message
  The message-type to send from the updater to the main thread. There’s only two variants, NewData which allows to send new data or StateChange which allows to signal readiness or error.

Traits

• DirectCacheAccess
  Trait for directly accessing the cache underneath any promise
• Promise
  Maybe this should rather be called “LazyUpdating”? Implementors can react to polling by queueing an update if needed. Update should force an update.

Type Definitions

• FutureResult
  Type alias for futures with BoxedSendError
• StringStatus
  This Status typedef allows to use both: &'static str and String in a message