added pmap method for arrays, with type/shape of result the same as map

base/abstractarray.jl

@@ -1324,6 +1324,17 @@ function map(f, A::AbstractArray)
     return map_to!(f, 2, dest, A)
 end
 
+function pmap(f, A::AbstractArray; err_retry=true, err_stop=false, pids = workers())
+    if isempty(A)
+        return isa(f,Type) ? similar(A,f) : similar(A)
+    end
+    results = pmap(f, rest(A, start(A)), err_retry=err_retry, err_stop=err_stop, pids=pids)
+    first = results[1]
+    dest = similar(A, typeof(first))
+    dest[1] = first
+    return map_to!(identity, 2, dest, results)
+end
+
 ## 2 argument
 function map!{F}(f::F, dest::AbstractArray, A::AbstractArray, B::AbstractArray)
     for i = 1:length(A)
@@ -1359,6 +1370,18 @@ function map(f, A::AbstractArray, B::AbstractArray)
     return map_to!(f, 2, dest, A, B)
 end
 
+function pmap(f, A::AbstractArray, B::AbstractArray; err_retry=true, err_stop=false, pids = workers())
+    shp = promote_shape(size(A),size(B))
+    if prod(shp) == 0
+        return similar(A, promote_type(eltype(A),eltype(B)), shp)
+    end
+    results = pmap(f, rest(A, start(A)), rest(B, start(B)), err_retry=err_retry, err_stop=err_stop, pids=pids)
+    first = results[1]
+    dest = similar(A, typeof(first), shp)
+    dest[1] = first
+    return map_to!(identity, 2, dest, results)
+end
+
 ## N argument
 
 ith_all(i, ::Tuple{}) = ()
@@ -1401,6 +1424,18 @@ function map(f, As::AbstractArray...)
     return map_to_n!(f, 2, dest, As)
 end
 
+function pmap(f, As::AbstractArray...; err_retry=true, err_stop=false, pids = workers())
+    shape = mapreduce(size, promote_shape, As)
+    if prod(shape) == 0
+        return similar(As[1], promote_eltype(As...), shape)
+    end
+    results = pmap(f, [rest(A,start(A)) for A in As]..., err_retry=err_retry, err_stop=err_stop, pids=pids)
+    first = results[1]
+    dest = similar(As[1], typeof(first), shape)
+    dest[1] = first
+    return map_to!(identity, 2, dest, results)
+end
+
 # multi-item push!, unshift! (built on top of type-specific 1-item version)
 # (note: must not cause a dispatch loop when 1-item case is not defined)
 push!(A, a, b) = push!(push!(A, a), b)

test/abstractarray.jl

@@ -424,6 +424,22 @@ function test_map(::Type{TestAbstractArray})
     @test map(f, Int[], Int[], Complex{Int}[]) == Number[]
 end
 
+#test pmap array methods for compatibility with map array methods
+A = B = C = 1:8
+#single arg
+mA,mpA = map(string,A), pmap(string,A)
+@test mA == mpA
+@test typeof(mA) = typeof(mpA)
+#double arg
+mAB,mpAB = map(string,A,B), pmap(string,A,B)
+@test mAB == mpAB
+@test typeof(mAB) == typeof(mpAB)
+#n arg
+mABC,mpABC = map(string,A,B,C), pmap(string,A,B,C)
+@test mABC == mpABC
+@test typeof(mABC) == typeof(mpABC)
+
+
 function test_map_promote(::Type{TestAbstractArray})
     A = [1:10...]
     f(x) = iseven(x) ? 1.0 : 1