Filtered array

src/Arrays/Arrays.jl

@@ -58,6 +58,7 @@ export CompressedArray
 export LocalToGlobalArray
 export LocalToGlobalPosNegArray
 export FilteredCellArray
+export FilterKernel
 
 export kernel_cache
 export kernel_caches

src/Arrays/FilteredArrays.jl

@@ -74,3 +74,34 @@ function getindex(a::FilteredCellArray,i::Integer...)
   cache = array_cache(a)
   getindex!(cache,a,i...)
 end
+
+struct FilterKernel <: Kernel end
+
+function kernel_return_type(f::FilterKernel,x...)
+  typeof(kernel_testitem(f,x...))
+end
+
+function kernel_cache(k::FilterKernel,f,a)
+  # vals = testitem(a)
+  vals = a
+  T = eltype(eltype(a))
+  r = zeros(T,length(vals))
+  c = CachedArray(r)
+end
+
+function apply_kernel!(cache,k::FilterKernel,f,a)
+  c = cache
+  vals = a
+  filters = f
+  @assert size(vals) == size(filters) "Local arrays mismatch"
+  setsize!(c,(sum(filters),))
+  r = c.array
+  i = 0
+  for (val,filter) in zip(vals,filters)
+    if filter
+      i += 1
+      r[i] = val
+    end
+  end
+  r
+end

test/ArraysTests/FilteredArraysTests.jl

@@ -21,6 +21,18 @@ fa = FilteredCellArray(a,filters)
 
 test_array(fa,[a[i][2:3] for i in 1:6])
 
+k = FilterKernel()
+
+cache = kernel_cache(k,filters[1],a[1])
+
+kernel_return_type(k,filters[1],a[1])
+
+apply_kernel!(cache,k,filters[1],a[1])
+
+test_kernel(k,(filters[1],a[1]),a[1][2:3])
+
+@test apply(k,filters,a) == fa
+
 #
 
 v1 = [ [2  4  3  3]; [2  4  3  3]]
@@ -48,4 +60,6 @@ res = [r1,r2,r3]
 r = CompressedArray(res,ptrs)
 test_array(fa,r)
 
+@test apply(k,filters,a) == fa
+
 end #module