telemere/projects/main/resources/signal-docstrings/catch-to-error!.txt
2024-09-20 22:55:12 +02:00

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Unconditionally executes given form and-
If form succeeds: return the form's result.
If form throws:
Call `error!` with the thrown error and the given signal options [2],
then return (:catch-val opts) if it exists, or rethrow the error.
API: [form] [id-or-opts form] => form's result (value/throw) (unconditional), or (:catch-val opts)
Default kind: `:error`
Default level: `:error`
Examples:
(catch->error! (/ 1 0)) ; %> {:kind :error, :level :error, :error <caught> ...}
(catch->error! ::my-id (/ 1 0)) ; %> {... :id ::my-id ...}
(catch->error!
{:let [x "x"] ; Available to `:data` and `:msg`
:data {:x x}
:msg ["My msg:" x my-error]
:catch-val "Return value when form throws"
:catch-sym my-error ; Sym of caught error, available to `:data` and `:msg`
}
(/ 1 0)) ; %> {... :data {x "x"}, :msg_ "My msg: x <caught>" ...}
Tips:
- Test using `with-signal`: (with-signal (catch->error! ...)).
- Supports the same options [2] as other signals [1].
- Useful for preventing errors from going unnoticed in futures, callbacks,
agent actions, etc.!: (future (catch->error ::my-future (do-something)))
See also `error!`.
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[1] See `help:signal-creators` - (`signal!`, `log!`, `event!`, ...)
[2] See `help:signal-options` - {:keys [kind level id data ...]}
[3] See `help:signal-content` - {:keys [kind level id data ...]}
[4] See `help:signal-filters` - (by ns/kind/id/level, sampling, etc.)