add length

src/backend/tensorflow/graph.jl

@@ -31,7 +31,7 @@ graph(::typeof(svd), x) = svd(x)
 
 for op in (*, .*, .+, .^, log, exp, ceil, floor, sqrt, abs, cos,
            sin, tan, atan, asin, acos, tanh, lgamma, erf, erfc, real, imag, conj,
-           inv, det, transpose, permutedims, cat)
+           inv, det, transpose, permutedims, cat, length)
   @eval graph(::typeof($op), args...) = $op(args...)
 end
 

test/backend/tensorflow.jl

@@ -36,6 +36,7 @@ end
   A1 = randn(Float32,(4,1))
   A2 = randn(Float32,(4,1))
   @test tf(@net (x,y) -> cat(2,x,y))(A1,A2) ≈ cat(2,A1,A2)
+  @test tf(@net x -> length(x))(A1) == length(A1)
 end
 
 end