Make slices writable

Author: trulsf

src/indexedarray.jl

@@ -67,7 +67,7 @@ end
 """
     unsafe_insertvar!(var::indexedVarArray{V,N,T}, index...)
 
-Insert a new variable with the given index withouth checking if the index is valid or
+Insert a new variable with the given index without checking if the index is valid or
  already assigned.
 """
 function unsafe_insertvar!(var::IndexedVarArray{V,N,T}, index...) where {V,N,T}

src/slice.jl

@@ -149,8 +149,26 @@ function Base.getindex(v::SparseArraySlice{P,V,NF,MT}, idx...) where {P,V,NF,MT}
     return v[idx]
 end
 
-function Base.setindex!(::SparseArraySlice, _, _...)
-    return error("SparseArraySlice is read-only")
+# Forward mutation to parent array
+function Base.setindex!(
+    v::SparseArraySlice{P,V,NF,MT},
+    val,
+    free_key::Tuple,
+) where {P,V,NF,MT}
+    length(free_key) == NF || throw(BoundsError(v, free_key))
+    T = _keytype(P)
+    v.parent[_reconstruct_key(v.mask, free_key, T)] = val
+    return val
+end
+
+# Splatted version
+function Base.setindex!(
+    v::SparseArraySlice{P,V,NF,MT},
+    val,
+    idx...,
+) where {P,V,NF,MT}
+    length(idx) == NF || throw(BoundsError(v, idx))
+    return setindex!(v, val, idx)
 end
 
 function Base.size(::SparseArraySlice)

test/runtests.jl

@@ -396,16 +396,20 @@ const _test_sa = testdata_sa()
     @test Base.IteratorSize(typeof(v)) == Base.HasLength()
     @test Base.IteratorEltype(typeof(v)) == Base.HasEltype()
 
+    # setindex
+    v2["bmw", 2002] = 200
+    @test v2["bmw", 2002] == 200
+    @test sa["bmw", 2002] == 200
+    v2[("bmw", 2002)] = 300
+    @test v2[("bmw", 2002)] == 300
+    @test sa[("bmw", 2002)] == 300
+
     # show / summary
     @test occursin("SparseArraySlice", sprint(summary, v))
     @test occursin("matching (\"ford\", Colon())", sprint(summary, v))
     @test occursin("(2000,) => 100", sprint(show, MIME("text/plain"), v))
     @test occursin("(2001,) => 150", sprint(show, MIME("text/plain"), v))
 
-    # read-only
-    @test_throws MethodError (v[(2000,)] = 999)
-    @test_throws ErrorException size(v)
-
     # wrong mask length
     @test_throws BoundsError slice(sa, "ford", :, :)