Skip to content

Added Signal.static #8

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
robertdp merged 1 commit into from
May 21, 2020
Merged

Added Signal.static #8

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
23 changes: 17 additions & 6 deletions src/Wire/Signal.purs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,23 +9,25 @@ import Wire.Event as Event
newtype Signal a
= Signal
{ event :: Event a
, modify :: (a -> a) -> Effect Unit
, read :: Effect a
, write :: a -> Effect Unit
, modify :: (a -> a) -> Effect Unit
}

create :: forall a. Eq a => a -> Effect { signal :: Signal a, cancel :: Effect Unit }
create init = do
value <- Ref.new init
inner <- Event.create
let
read' = Ref.read value

write' a = modify' (const a)

modify' f = Ref.modify f value >>= inner.push

signal = Signal { event: Event.distinct inner.event, read: read', write: write', modify: modify' }
signal =
Signal
{ event: Event.distinct inner.event
, read: Ref.read value
, write: modify' <<< const
, modify: modify'
}
pure { signal, cancel: inner.cancel }

subscribe :: forall a. Signal a -> Subscriber a -> Effect Canceler
Expand All @@ -44,3 +46,12 @@ write a (Signal s) = s.write a

modify :: forall a. (a -> a) -> Signal a -> Effect Unit
modify f (Signal s) = s.modify f

static :: forall a. a -> Signal a
static a =
Signal
{ event: pure a
, read: pure a
, modify: const mempty
, write: const mempty
}