recurrence overhaul mostly working

src/compiler/interp.jl

@@ -40,3 +40,5 @@ function interpmodel_(m, args...)
 end
 
 interpmodel(m, args...) = @ithrow runrawbatched((xs...) -> interpmodel_(m, xs...), args...)
+
+runmodel(m::Capacitor, xs...) = @ithrow interpmodel_(m, xs...)

src/compiler/loops.jl

@@ -104,22 +104,9 @@ end
 
 unrollgraph(m, n; kws...) = unrollgraph(atomise(m), n; kws...)
 
-# TODO: perhaps split into SeqModel + StatefulModel
-type Unrolled <: Model
-  model
-  graph::IVertex{Any}
-  state::Vector{Any}
-  stateful::Bool
-  steps::Int
-end
-
-(m::Unrolled)(xs...) = interpret(reifyparams(m.graph), xs...)
-
-graph(u::Unrolled) = u.graph
-
 function unroll(model, n)
   graph, state = unrollgraph(model, n)
-  Unrolled(model, graph, state, true, n)
+  SeqModel(Stateful(Capacitor(graph), state), n)
 end
 
 function unseqin(v::IVertex)
@@ -135,7 +122,7 @@ unseq(graph) = unseqout(unseqin(graph))
 
 function unroll1(model)
   graph, state = unrollgraph(model, 1)
-  Unrolled(model, unseq(graph), state, false, 1)
+  Stateful(Capacitor(graph), state)
 end
 
 flip(model) = Capacitor(map(x -> x isa Offset ? -x : x, atomise(model)))

src/model.jl

@@ -46,6 +46,16 @@ methods as necessary.
 """
 graph(m) = nothing
 
+"""
+`runmodel(m, ...)` is like `m(...)`, i.e. it runs the forward pass. However,
+unlike direct calling, it does not try to apply batching and simply uses the
+inputs directly.
+
+This function should be considered an implementation detail; it will be
+eventually be replaced by a non-hacky way of doing batching.
+"""
+function runmodel end
+
 # Model parameters
 
 # TODO: should be AbstractArray?
@@ -111,7 +121,30 @@ struct Capacitor <: Model
   graph::IVertex{Any}
 end
 
-# TODO: batching
 (m::Capacitor)(xs...) = interpmodel(m, xs...)
 
 graph(cap::Capacitor) = cap.graph
+
+# Recurrent Models
+
+mutable struct Stateful <: Model
+  model
+  state::Vector{Any}
+end
+
+function (m::Stateful)(x)
+  runrawbatched(x) do x
+    state, y = runmodel(m.model, (m.state...,), x)
+    m.state = collect(state)
+    return y
+  end
+end
+
+struct SeqModel
+  model
+  steps::Int
+end
+
+# TODO: multi input
+# TODO: lift sequences
+(m::SeqModel)(x) = m.model(x)