makesession refactor

src/backend/tensorflow/graph.jl

@@ -70,17 +70,3 @@ end
 TensorFlow.Tensor(m::Flux.Model, args...) = tograph(m, args...)[2]
 
 RawTensor(data::Union{Batch,Seq}) = RawTensor(rawbatch(data))
-
-function makesession(model, n)
-  sess = Session(Graph())
-  inputs = [placeholder(Float32) for _ = 1:n]
-  params, output = tograph(model, inputs...)
-  run(sess, initialize_all_variables())
-  sess, params, inputs, output
-end
-
-function storeparams!(sess, params)
-  for (p, t) in params
-    p.x = run(sess, t)
-  end
-end

src/backend/tensorflow/model.jl

@@ -6,14 +6,28 @@ type Model
   output::Any
 end
 
-ismultioutput(m::Model) = !isa(m.output, Tensor)
-
-function tf(model)
-  sess, params, input, output = makesession(model, 1)
-  Model(model, sess, params,
-        input, output)
+function makesession(model, inputs; session = Session(Graph()))
+  params, output = tograph(model, inputs...)
+  run(session, initialize_all_variables())
+  Model(model, session, params, inputs, output)
 end
 
+function makesession(model, n::Integer; session = Session(Graph()))
+  makesession(model, [placeholder(Float32) for _ = 1:n], session = session)
+end
+
+tf(model) = makesession(model, 1)
+
+function storeparams!(sess, params)
+  for (p, t) in params
+    p.x = run(sess, t)
+  end
+end
+
+storeparams!(m::Model) = storeparams!(m.session, m.params)
+
+ismultioutput(m::Model) = !isa(m.output, Tensor)
+
 function batch(xs)
   dims = ndims(xs)-1
   T = Array{eltype(xs),dims}