Added the offset kwarg to domainview()

Project.toml

@@ -1,7 +1,7 @@
 name = "BlockHaloArrays"
 uuid = "8029ca6b-11ad-4a59-88a2-2e6eee4ef8a2"
 authors = ["Sam Miller <[email protected]> and contributors"]
-version = "0.4.4"
+version = "0.4.5"
 
 [deps]
 EllipsisNotation = "da5c29d0-fa7d-589e-88eb-ea29b0a81949"

src/BlockHaloArrays.jl

@@ -303,10 +303,22 @@ end
 
 Get the SubArray view of the domain region of a block in the BlockHaloArray.
 """
-function domainview(A::BlockHaloArray, blockid::Integer)
+function domainview(A::BlockHaloArray, blockid::Integer;offset=0)
+
+    if offset > A.nhalo
+        error("offset must be <= nhalo")
+    end
+
+    if offset < 0
+        error("offset must be > 0")
+    end
+
     _, _, lo_dom_start, _ = lo_indices(A.blocks[blockid], A.nhalo)
     _, hi_dom_end, _, _ = hi_indices(A.blocks[blockid], A.nhalo)
 
+    lo_dom_start = lo_dom_start .- offset
+    hi_dom_end = hi_dom_end .+ offset
+
     idx_range = UnitRange.(lo_dom_start, hi_dom_end)
     idx_range_vec = collect(idx_range)
     for dim in eachindex(idx_range_vec)

test/unit/test_util_funcs.jl

@@ -11,6 +11,22 @@
     @test size(haloview(A, 1, :jhi)) == (25, 2)
 end
 
+@testitem "domainview" begin
+    include("common.jl")
+    nhalo = 3
+    nblocks = 4
+    dims = (40,40)
+    A = BlockHaloArray(dims, nhalo, nblocks)
+
+    blockid = 1
+    @test size(domainview(A, blockid)) == (20, 20)
+    @test size(domainview(A, blockid; offset=1)) == (22, 22)
+    @test size(domainview(A, blockid; offset=2)) == (24, 24)
+    @test size(domainview(A, blockid; offset=3)) == (26, 26)
+    @test_throws ErrorException domainview(A, blockid; offset=4)
+    @test_throws ErrorException domainview(A, blockid; offset=-1)
+end
+
 @testitem "nblocks" begin
     include("common.jl")
     A = BlockHaloArray((50,50), 2, 4)