Lift unroll

Outputs the length of a list, followed by each of its elements as separate messages on a second stream.

Use this when

• You need both the batch size and the individual elements for downstream processing.
• You are about to flatten a list but want to preserve the original grouping for a later Lift reroll.
• Downstream logic requires cardinality (e.g. "process N items, then emit summary").

What it does

Consumes one list per tick. On the size output, emits the list length as UInt64. On the items output, emits every element of the list in order, one per tick. Input [0, 1, 2, 3, 4] produces size 5 and items 0, 1, 2, 3, 4.

Inputs

Type	Description
[t]	A list of any type.

Outputs

Type	Description
UInt64	Size of the list.
t	One message per list element.

Parameters

This transformation takes no parameters.

Works best with

• Lift reroll — together they round-trip a list through element-wise processing.
• Downstream components that need both per-item processing and an overall count.

Caveats

• The two output streams must be kept synchronized downstream.
• Empty lists still produce a size of 0 and no item messages.