diff options
Diffstat (limited to '')
| -rw-r--r-- | stdlib/source/lux/concurrency/stm.lux | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/stdlib/source/lux/concurrency/stm.lux b/stdlib/source/lux/concurrency/stm.lux index b9f337024..06912a25a 100644 --- a/stdlib/source/lux/concurrency/stm.lux +++ b/stdlib/source/lux/concurrency/stm.lux @@ -30,6 +30,7 @@ #observers (Dict Text (-> a (IO Unit)))}) (type: #export (Var a) + {#;doc "A mutable cell containing a value, and observers that will be alerted of any change to it."} (Atom (Var-State a))) (type: (Tx-Frame a) @@ -41,9 +42,11 @@ (List (Ex [a] (Tx-Frame a)))) (type: #export (STM a) + {#;doc "A computation which updates a transaction and produces a value."} (-> Tx [Tx a])) (def: #export (var value) + {#;doc "Creates a new STM var, with a default value."} (All [a] (-> a (Var a))) (atom;atom {#value value #observers (dict;new text;Hash<Text>)})) @@ -128,6 +131,9 @@ (write! new-value var)))) (def: #export (unfollow label target) + {#;doc "Stop tracking the changes to a Var. + + Caveat emptor: It won't close any Chan that used to track the changes."} (All [a] (-> Text (Var a) (IO Unit))) (do Monad<IO> [[value observers] (atom;get target)] @@ -135,7 +141,7 @@ target))) (def: #export (follow label target) - {#;doc "Creates a channel (identified by a given text) that will receive all changes to the value of the given var."} + {#;doc "Creates a channel (identified by a label) that will receive all changes to the value of the given var."} (All [a] (-> Text (Var a) (IO (frp;Chan a)))) (let [head (frp;chan ($ +0)) chan-var (var head) @@ -181,17 +187,19 @@ (ma tx'))))) (def: #export (update! f var) - (All [a] (-> (-> a a) (Var a) (Promise [a a]))) - (P;future (io (loop [_ []] - (let [(^@ state [value observers]) (io;run (atom;get var)) - value' (f value)] - (if (io;run (atom;compare-and-swap state - [value' observers] - var)) - [value value'] - (recur []))))))) + {#;doc "Will update a Var's value, and return a tuple with the old and the new values."} + (All [a] (-> (-> a a) (Var a) (IO [a a]))) + (io (loop [_ []] + (let [(^@ state [value observers]) (io;run (atom;get var)) + value' (f value)] + (if (io;run (atom;compare-and-swap state + [value' observers] + var)) + [value value'] + (recur [])))))) (def: #export (update f var) + {#;doc "Will update a Var's value, and return a tuple with the old and the new values."} (All [a] (-> (-> a a) (Var a) (STM [a a]))) (do Monad<STM> [a (read var) |