S0005: unknown event in feedback clause

Generated from rellum-diagnostics/src/db.rs.

Explanation

~ feedback clauses can react only to event bindings declared in the reactive graph. If an on-clause names something that is not an event, the compiler cannot know when that state update should run.

Common causes

• misspelling an event name in an on-clause
• using a derived value or state binding where an event name is required
• declaring the event in a module where reactive bindings are not visible

Canonical fixes

• name an existing event in the feedback clause

Before:

count ~ feedback(
    on pres => count + 1,
    0
)

After:

press = event(button!())
count ~ feedback(
    on press => count + 1,
    0
)

• declare the event before using it in feedback

Code example

count ~ feedback(
    on pres => count + 1,
    0
)

Links

• RellC diagnostic overview