From 79b0501d13e72f2929c58124a0bb5aa765882fd7 Mon Sep 17 00:00:00 2001
From: Tim Besard <tim.besard@gmail.com>
Date: Fri, 24 Aug 2018 14:44:48 +0200
Subject: [PATCH 1/2] Use broadcast expressions instead of some loops.

---
 src/apiutils.jl | 20 ++++++--------------
 src/gradient.jl |  5 ++---
 2 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/src/apiutils.jl b/src/apiutils.jl
index eec39653..44b931df 100644
--- a/src/apiutils.jl
+++ b/src/apiutils.jl
@@ -53,36 +53,28 @@ end
 
 function seed!(duals::AbstractArray{Dual{T,V,N}}, x,
                seed::Partials{N,V} = zero(Partials{N,V})) where {T,V,N}
-    for i in eachindex(duals)
-        duals[i] = Dual{T,V,N}(x[i], seed)
-    end
+    duals .= Dual{T,V,N}.(x, Base.RefValue(seed))
     return duals
 end
 
 function seed!(duals::AbstractArray{Dual{T,V,N}}, x,
                seeds::NTuple{N,Partials{N,V}}) where {T,V,N}
-    for i in 1:N
-        duals[i] = Dual{T,V,N}(x[i], seeds[i])
-    end
+    duals[1:N] .= Dual{T,V,N}.(x[1:N], seeds[1:N])
     return duals
 end
 
 function seed!(duals::AbstractArray{Dual{T,V,N}}, x, index,
                seed::Partials{N,V} = zero(Partials{N,V})) where {T,V,N}
     offset = index - 1
-    for i in 1:N
-        j = i + offset
-        duals[j] = Dual{T,V,N}(x[j], seed)
-    end
+    chunk = (1:N) .+ offset
+    duals[chunk] .= Dual{T,V,N}.(x[chunk], Base.RefValue(seed))
     return duals
 end
 
 function seed!(duals::AbstractArray{Dual{T,V,N}}, x, index,
                seeds::NTuple{N,Partials{N,V}}, chunksize = N) where {T,V,N}
     offset = index - 1
-    for i in 1:chunksize
-        j = i + offset
-        duals[j] = Dual{T,V,N}(x[j], seeds[i])
-    end
+    chunk = (1:chunksize) .+ offset
+    duals[chunk] .= Dual{T,V,N}.(x[chunk], seeds[1:chunksize])
     return duals
 end
diff --git a/src/gradient.jl b/src/gradient.jl
index 8721af6d..771bffa7 100644
--- a/src/gradient.jl
+++ b/src/gradient.jl
@@ -77,9 +77,8 @@ extract_gradient!(::Type{T}, result::AbstractArray, dual::Dual) where {T}= copyt
 
 function extract_gradient_chunk!(::Type{T}, result, dual, index, chunksize) where {T}
     offset = index - 1
-    for i in 1:chunksize
-        result[i + offset] = partials(T, dual, i)
-    end
+    chunk = (1:chunksize) .+ offset
+    result[chunk] .= ForwardDiff.partials(T, dual, 1:chunksize)
     return result
 end
 

From 9d21d51b1629de2dffe4624b29e212aa756c8a81 Mon Sep 17 00:00:00 2001
From: Tim Besard <tim.besard@gmail.com>
Date: Mon, 27 Aug 2018 14:21:12 +0200
Subject: [PATCH 2/2] Forward all calls to getindex(::Partials) to the inner
 container.

Otherwise we always return an Array, where a Tuple would have sufficed
(eg. when indexing with ranges).
---
 src/partials.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/partials.jl b/src/partials.jl
index 5734a434..e8af95e4 100644
--- a/src/partials.jl
+++ b/src/partials.jl
@@ -20,7 +20,7 @@ end
 @inline Base.length(::Partials{N}) where {N} = N
 @inline Base.size(::Partials{N}) where {N} = (N,)
 
-@inline Base.@propagate_inbounds Base.getindex(partials::Partials, i::Int) = partials.values[i]
+@inline Base.@propagate_inbounds Base.getindex(partials::Partials, I...) = partials.values[I...]
 
 Base.iterate(partials::Partials) = iterate(partials.values)
 Base.iterate(partials::Partials, i) = iterate(partials.values, i)