Get the actor name from an expression

iex> Chorex.actor_from_local_exp((quote do: Foo.bar(42)), __ENV__)
{:ok, Foo}copy

Define a new choreography.

See the documentation for the Chorex module for more details.

True if the continuation for the given code is empty. This can be from an empty block, or because the projection of block does nothing meaningful.

Perform the control merge function.

Flatten block expressions at each step: sometimes auxiliary blocks get created around bits of the projection; trim these out at this step so equivalent expressions look equivalent.

@spec project(term :: term(), env :: Macro.Env.t(), label :: atom(), ctx :: map()) ::
  WriterMonad.t()

Perform endpoint projection in the context of node label.

This returns a pair of a projection for the label, and a list of behaviors that an implementer of the label must implement.

Arguments:

1. Elixir AST term to project.
2. Macro environment.
3. Name of the actor currently under projection. Atom.
4. Extra information about the expansion. Map. Contains:
   • vars :: set of live variables
   • actors :: list of all actor names

Returns an instance of the WriterMonad, which is just a 3-tuple containing:

1. The projected term. Elixir AST.
2. A list of callback specifications for this actor. (Functions the actor implementer needs to have.)
3. List of auxiliary functions generated during the projection process.

Project an expression like Actor.var to either var or _.

Project to var when Actor matches the label we're projecting to, or _ so that whatever data flows to that point can't be captured.

Project local expressions of the form ActorName.(something).

Like project/4, but focus on handling ActorName.(local_var), ActorName.local_func() or ActorName.(local_exp). Handles walking the local expression to gather list of functions needed for the behaviour to implement.

@spec project_sequence(term(), Macro.Env.t(), atom(), map()) :: WriterMonad.t()

Project a sequence of expressions.

@spec start(module(), %{required(atom()) => module() | remote_actor_ref()}, [any()]) ::
  any()

Start a choreography.

Takes a choreography module like MyCoolThing.Chorex, a map from actor names to implementing modules, and a list of arguments to pass to the run function.

Values in the map are either modules or remote_actor_ref() tuples.

Example

Chorex.start(ThreePartySeller.Chorex,
             %{ Buyer1 => MyBuyer1, Buyer2 => MyBuyer2, Seller => MySeller },
             [])copy

Walks a local expression to pull out/convert function calls.

The expr in Alice.(expr) can almost be dropped directly into the projection for the Alice node. Here's where that almost comes in:

• Alice.(1 + foo()) needs to be rewritten as 1 + impl.foo() and foo/0 needs to be added to the list of functions for the Alice behaviour.

• Alice.some_func(&other_local_func/2) needs to be rewritten as impl.some_func(&impl.other_local_func/2) and both some_func and other_local_func need to be added to the list of functions for the Alice behaviour.

• Alice.(1 + Enum.sum(...)) should not be rewritten as impl.….

There is some subtlety around tuples and function calls. Consider how these expressions and their quoted representations compare:

• {:ok, foo} → {:ok, {:foo, [], …}}

• {:ok, foo, bar} → {:{}, [], [:ok, {:foo, [], …}, {:bar, [], …}]}

• ok(bar) → {:ok, [], [{:bar, [], …}]}

It seems that 2-tuples have some special representation, which is frustrating.