Runic.Workflow.Accumulator (Runic v0.1.0-alpha.7)

Accumulator components aggregate values over time using a reducer function.

Options

:mergeable - When true, indicates this accumulator's reducer has CRDT-like properties (commutative, idempotent, associative) and is safe for parallel merge without ordering guarantees. Defaults to false.

Example

# A counter is mergeable (addition is commutative and associative)
accumulator(
  init: fn -> 0 end,
  reducer: fn value, acc -> acc + value end,
  mergeable: true
)

# A list accumulator is NOT mergeable (order matters)
accumulator(
  init: fn -> [] end,
  reducer: fn value, acc -> [value | acc] end,
  mergeable: false
)

Runtime Context

Accumulators can reference external runtime values via context/1 in their reducer function. When detected, the reducer is rewritten to arity-3 (value, acc, meta_ctx) and values are resolved from the workflow's run_context.

Runic.accumulator(0, fn x, state -> state + x * context(:factor) end,
  name: :scaled
)

Use context/2 to provide defaults:

Runic.accumulator(0, fn x, state -> state + x * context(:factor, default: 1) end,
  name: :scaled
)

Summary

Types

t()

Functions

has_meta_refs?(accumulator)

Returns whether this accumulator has meta references (e.g., context/1) that need to be resolved during the prepare phase.

Types

t()

@type t() :: %Runic.Workflow.Accumulator{
  closure: term(),
  hash: term(),
  init: term(),
  inputs: term(),
  mergeable: term(),
  meta_refs: term(),
  name: term(),
  outputs: term(),
  reduce_hash: term(),
  reducer: term()
}

Functions

has_meta_refs?(accumulator)

@spec has_meta_refs?(t()) :: boolean()

Returns whether this accumulator has meta references (e.g., context/1) that need to be resolved during the prepare phase.