From 2b0f02fb66d21d5f5902193514e23f576bb6f5fc Mon Sep 17 00:00:00 2001
From: Tim Holy <tim.holy@gmail.com>
Date: Mon, 25 Apr 2016 08:20:31 -0500
Subject: [PATCH] Add `value` to support sync over dimensional index/value

---
 src/ArrayIterationPlayground.jl |  2 +-
 src/core.jl                     | 21 +++++++++++++++++++--
 test/dense.jl                   | 12 ++++++++++++
 3 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/src/ArrayIterationPlayground.jl b/src/ArrayIterationPlayground.jl
index 07648e1..ff8c5e2 100644
--- a/src/ArrayIterationPlayground.jl
+++ b/src/ArrayIterationPlayground.jl
@@ -4,7 +4,7 @@ import Base: getindex, setindex!, start, next, done, length, eachindex, show, pa
 using Base: ReshapedArray, linearindexing, LinearFast, LinearSlow
 using Base.PermutedDimsArrays: PermutedDimsArray
 
-export inds, index, stored, each, sync
+export inds, index, value, stored, each, sync
 
 include("types.jl")
 include("core.jl")
diff --git a/src/core.jl b/src/core.jl
index 80fb992..d6c5330 100644
--- a/src/core.jl
+++ b/src/core.jl
@@ -23,10 +23,23 @@ create an iterator from a hint, call `each` on the resulting object.
 In contrast to `eachindex` iteration over a subarray of `A`, the
 indexes are for `A` itself.
 
-See also: `stored`, `each`.
+See also: `value`, `stored`, `each`.
 """
 index{A,I,isindex,isstored}(w::ArrayIndexingWrapper{A,I,isindex,isstored}) = ArrayIndexingWrapper{A,I,true,isstored}(w.data, w.indexes)
 
+"""
+`value(A)`
+`value(A, indexes...)`
+
+`value` creates an "iteration hint" that records the region of `A`
+that you wish to iterate over. The iterator will return the values,
+rather than the indexes, of `A`. "iteration hints" are not iterables; to
+create an iterator from a hint, call `each` on the resulting object.
+
+See also: `index`, `stored`, `each`.
+"""
+value{A,I,isindex,isstored}(w::ArrayIndexingWrapper{A,I,isindex,isstored}) = ArrayIndexingWrapper{A,I,true,isstored}(w.data, w.indexes)
+
 """
 `stored(A)`
 `stored(A, indexes...)`
@@ -36,7 +49,7 @@ that you wish to iterate over. The iterator will return just the
 stored values of `A`. "iteration hints" are not iterables; to create
 an iterator from a hint, call `each` on the resulting object.
 
-See also: `index`, `each`.
+See also: `index`, `value`, `each`.
 """
 stored{A,I,isindex,isstored}(w::ArrayIndexingWrapper{A,I,isindex,isstored}) = ArrayIndexingWrapper{A,I,isindex,true}(w.data, w.indexes)
 
@@ -46,6 +59,10 @@ index(A::AbstractArray) = index(A, allindexes(A))
 index(A::AbstractArray, I::IterIndex...) = index(A, I)
 index{T,N}(A::AbstractArray{T,N}, indexes::NTuple{N,IterIndex}) = ArrayIndexingWrapper{typeof(A),typeof(indexes),true,false}(A, indexes)
 
+value(A::AbstractArray) = value(A, allindexes(A))
+value(A::AbstractArray, I::IterIndex...) = value(A, I)
+value{T,N}(A::AbstractArray{T,N}, indexes::NTuple{N,IterIndex}) = ArrayIndexingWrapper{typeof(A),typeof(indexes),false,false}(A, indexes)
+
 stored(A::AbstractArray) = stored(A, allindexes(A))
 stored(A::AbstractArray, I::IterIndex...) = stored(A, I)
 stored{T,N}(A::AbstractArray{T,N}, indexes::NTuple{N,IterIndex}) = ArrayIndexingWrapper{typeof(A),typeof(indexes),false,true}(A, indexes)
diff --git a/test/dense.jl b/test/dense.jl
index b2133d4..9f89e30 100644
--- a/test/dense.jl
+++ b/test/dense.jl
@@ -165,3 +165,15 @@ goodcopy!(D, Cc)
 mysum!(C, D, A)
 @test C[1,2] == 23
 @test C[2,1] == 32
+
+# sync with dimension iterators
+fill!(B, -1)
+for (I, a) in sync(index(B, :, 2), value(A, :, 1))
+    B[I] = a
+end
+@test B == [-1 A[1,1]; -1 A[2,1]]
+fill!(B, -1)
+for (IB, IA) in sync(index(B, :, 1), index(A, :, 2))
+    B[IB] = A[IA]
+end
+@test B == [A[1,2] -1; A[2,2] -1]