Aggregate: Carry
Sample-and-hold memory cell. When a value arrives on write, it is stored AND
emitted on result. When a value arrives on trigger (without a write),
the most recently held value is re-emitted (or the configured Default value
on the very first trigger).
Useful inside iterator bodies to carry a constant or a previously-computed
value across iterations. When a Value type is set, written values are
type-checked against it — mismatched writes fail the step. When no type is
configured, type checking of writes is skipped.
write=7 → result=7
trigger → result=7
write=11 → result=11
trigger → result=11
Parameters
Wire type the carry holds (String, Number, JSON, …). Determines both
the type accepted on write and the type emitted on result. In the
editor this is the type selector of the combined Default value control:
choosing a type also sets the default value's type. Optional at the
configuration level — when empty, type checking of writes is skipped.
Value emitted on the first trigger call before anything has been
written. Entered together with Value type as a single typed-value
control; the form always seeds a default (empty text by default), so a
trigger-only call before any write emits this value.
Input
New value to store and emit. Must match the configured Value type.
Re-emit the last held value (any value type — only its arrival matters).
Output
The value that was just written, or the most recently held value when only
trigger fired.