diff --git a/REQUIRE b/REQUIRE
index b31bc6ad..b75b59ca 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -7,6 +7,8 @@ Requires
 Adapt
 GZip
 Colors
+ZipFile
+AbstractTrees
 
 # AD
 ForwardDiff 0.5.0
diff --git a/src/Flux.jl b/src/Flux.jl
index 88b2108e..159f7325 100644
--- a/src/Flux.jl
+++ b/src/Flux.jl
@@ -34,10 +34,11 @@ include("layers/conv.jl")
 include("layers/recurrent.jl")
 include("layers/normalisation.jl")
 
-include("jit/JIT.jl")
-
+include("batches/Batches.jl")
 include("data/Data.jl")
 
+include("jit/JIT.jl")
+
 @require CuArrays include("cuda/cuda.jl")
 
 end # module
diff --git a/src/batches/Batches.jl b/src/batches/Batches.jl
new file mode 100644
index 00000000..a2424549
--- /dev/null
+++ b/src/batches/Batches.jl
@@ -0,0 +1,9 @@
+module Batches
+
+import ..Flux
+
+export Tree
+
+include("tree.jl")
+
+end
diff --git a/src/batches/tree.jl b/src/batches/tree.jl
new file mode 100644
index 00000000..5067714a
--- /dev/null
+++ b/src/batches/tree.jl
@@ -0,0 +1,42 @@
+using AbstractTrees
+
+struct Tree{T}
+  value::T
+  children::Vector{Tree{T}}
+end
+
+Tree{T}(x::T, xs::Tree{T}...) where T = Tree{T}(x, [xs...])
+Tree{T}(x) where T = Tree(convert(T, x))
+
+Tree(x::T, xs::Tree{T}...) where T = Tree{T}(x, xs...)
+
+AbstractTrees.children(t::Tree) = t.children
+AbstractTrees.printnode(io::IO, t::Tree) = show(io, t.value)
+
+Base.show(io::IO, t::Type{Tree}) = print(io, "Tree")
+Base.show(io::IO, t::Type{Tree{T}}) where T = print(io, "Tree{", T, "}")
+
+function Base.show(io::IO, t::Tree)
+  println(io, typeof(t))
+  print_tree(io, t)
+end
+
+using Juno
+
+@render Juno.Inline t::Tree begin
+  render(t) = Juno.Tree(t.value, render.(t.children))
+  Juno.Tree(typeof(t), [render(t)])
+end
+
+Base.getindex(t::Tree, i::Integer) = t.children[i]
+Base.getindex(t::Tree, i::Integer, is::Integer...) = t[i][is...]
+
+# Utilities
+
+isleaf(t) = isempty(children(t))
+
+leaves(xs::Tree) = map(x -> x.value, Leaves(xs))
+
+Base.map(f, t::Tree, ts::Tree...) =
+  Tree{Any}(f(map(t -> t.value, (t, ts...))...),
+            [map(f, chs...) for chs in zip(map(t -> t.children, (t, ts...))...)]...)
diff --git a/src/data/Data.jl b/src/data/Data.jl
index 2844d0ae..e2118029 100644
--- a/src/data/Data.jl
+++ b/src/data/Data.jl
@@ -1,5 +1,7 @@
 module Data
 
+import ..Flux
+
 export CMUDict, cmudict
 
 deps(path...) = joinpath(@__DIR__, "..", "..", "deps", path...)
@@ -12,4 +14,7 @@ include("mnist.jl")
 include("cmudict.jl")
 using .CMUDict
 
+include("sentiment.jl")
+using .Sentiment
+
 end
diff --git a/src/data/sentiment.jl b/src/data/sentiment.jl
new file mode 100644
index 00000000..8ac7a5a1
--- /dev/null
+++ b/src/data/sentiment.jl
@@ -0,0 +1,45 @@
+module Sentiment
+
+using ZipFile
+using ..Data: deps
+
+function load()
+  isfile(deps("sentiment.zip")) ||
+    download("https://nlp.stanford.edu/sentiment/trainDevTestTrees_PTB.zip",
+             deps("sentiment.zip"))
+  return
+end
+
+getfile(r, name) = r.files[findfirst(x -> x.name == name, r.files)]
+
+function getfile(name)
+  r = ZipFile.Reader(deps("sentiment.zip"))
+  text = readstring(getfile(r, "trees/$name"))
+  close(r)
+  return text
+end
+
+using ..Flux.Batches
+
+totree_(n, w) = Tree{Any}((parse(Int, n), w))
+totree_(n, a, b) = Tree{Any}((parse(Int, n), nothing), totree(a), totree(b))
+totree(t::Expr) = totree_(t.args...)
+
+function parsetree(s)
+  s = replace(s, r"\$", s -> "\\\$")
+  s = replace(s, r"[^\s\(\)]+", s -> "\"$s\"")
+  s = replace(s, " ", ", ")
+  return totree(parse(s))
+end
+
+function gettrees(name)
+  load()
+  ss = split(getfile("$name.txt"), '\n', keep = false)
+  return parsetree.(ss)
+end
+
+train() = gettrees("train")
+test() = gettrees("test")
+dev() = gettrees("dev")
+
+end