remove gradient support for now

src/backend/tensorflow/model.jl

@@ -4,7 +4,6 @@ type Model
   params::Dict{Flux.Param,Tensor}
   inputs::Vector{Tensor}
   output::Any
-  gradients::Vector{Tensor}
 end
 
 ismultioutput(m::Model) = !isa(m.output, Tensor)
@@ -12,8 +11,7 @@ ismultioutput(m::Model) = !isa(m.output, Tensor)
 function tf(model)
   sess, params, input, output = makesession(model, 1)
   Model(model, sess, params,
-        input, output,
-        gradients(output, input))
+        input, output)
 end
 
 function batch(xs)
@@ -38,14 +36,10 @@ function (m::Model)(args...)
   ismultioutput(m) ? map(first, output) : first(output)
 end
 
-function Flux.back!(m::Model, Δ, args...)
-  @assert length(args) == length(m.inputs)
-  # TODO: keyword arguments to `gradients`
-  run(m.session, m.gradients[1], Dict(zip(m.inputs, args)))
-end
-
-function Flux.update!(m::Model)
-  error("update! is not yet supported on TensorFlow models")
+for f in :[back!, update!].args
+  @eval function Flux.$f(m::Model, args...)
+    error($(string(f)) * " is not yet supported on TensorFlow models")
+  end
 end
 
 import Juno: info

src/backend/tensorflow/recurrent.jl

@@ -27,8 +27,7 @@ function tf(model::Flux.Unrolled)
   sess, params, (instates, input), (outstates, output) = makesession(model)
   SeqModel(
     Model(model, sess, params,
-          [instates..., input], [outstates..., output],
-          [placeholder(Float32)]),
+          [instates..., input], [outstates..., output]),
     model.state)
 end