| Safe Haskell | Safe |
|---|---|
| Language | Haskell2010 |
MagicWormhole.Internal.Sequential
Description
Helpers for processing messages in sequence.
Synopsis
- data Sequential counter item
- sequenceBy :: (Hashable counter, Eq counter) => (a -> counter) -> counter -> STM (Sequential counter a)
- insert :: (Ord counter, Enum counter, Hashable counter, Eq counter) => Sequential counter a -> a -> STM Bool
- next :: (Enum counter, Eq counter, Hashable counter) => Sequential counter a -> STM a
Documentation
data Sequential counter item Source #
A thing that gets numbered items and then buffers them so you can read them in order without gaps.
"counter" is an Enum that is used to determine the ordering of the
elements, and "item" is the type of the items themselves.
Arguments
| :: (Hashable counter, Eq counter) | |
| => (a -> counter) | How to rank items |
| -> counter | The expected rank of the first item |
| -> STM (Sequential counter a) |
Create a Sequential value for a series of item.
insert :: (Ord counter, Enum counter, Hashable counter, Eq counter) => Sequential counter a -> a -> STM Bool Source #
Insert an item into the sequence. It may only be drawn from the
sequence with next when its counter is next one.
If the counter has already been past, don't insert it, since we'll never
reach it. Instead return False.
Arguments
| :: (Enum counter, Eq counter, Hashable counter) | |
| => Sequential counter a | How item are ordered in sequence |
| -> STM a | The next item |
Get and remove the next item from the sequence. This will block until there is an item with the exact rank we are expecting.