telemere/projects/main/resources/signal-docstrings/signal-creators.txt

Call a Telemere signal creator to conditionally create a signal at that callsite.

When filtering conditions are met [4], the call creates a Telemere signal [3]
and dispatches it to registered handlers for processing (e.g. writing to
console/file/queue/db, etc.).

Telemere doesn't make a hard distinction between different kinds of signals
(log, event, error, etc.) - they're all just plain Clojure/Script maps with
various keys:

  - All signal creators offer the same options [2], and
  - All signal kinds can contain the same content [3]

Creators vary only in in their default options and call APIs (expected args
and return values), making them more/less convenient for certain use cases:

  `event!` -------- [id   ] or [id   opts/level] => true iff signal was created (allowed)
  `log!` ---------- [msg  ] or [opts/level  msg] => true iff signal was created (allowed)
  `error!` -------- [error] or [opts/id   error] => given error (unconditional)
  `trace!` -------- [form ] or [opts/id    form] => form result (value/throw) (unconditional)
  `spy!` ---------- [form ] or [opts/level form] => form result (value/throw) (unconditional)
  `catch->error!` - [form ] or [opts/id    form] => form value, or given fallback
  `signal!` ------- [opts ]                      => depends on options

- `log!` and `event!` are both good default/general-purpose signal creators.
- `log!` emphasizes messages, while `event!` emphasizes ids.
- `signal!` is the generic creator, and is used by all the others.

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[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.)