Fix incorrect perm, generalize some constructors (#24)

Author: mtfishman

Project.toml

@@ -1,7 +1,7 @@
 name = "NamedDimsArrays"
 uuid = "60cbd0c0-df58-4cb7-918c-6f5607b73fde"
 authors = ["ITensor developers <[email protected]> and contributors"]
-version = "0.3.8"
+version = "0.3.9"
 
 [deps]
 Adapt = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"

src/abstractnameddimsarray.jl

@@ -152,6 +152,9 @@ const NamedDimsAxis = AbstractNamedUnitRange{
 
 # Generic constructor.
 function nameddims(a::AbstractArray, nameddimsindices)
+  if iszero(ndims(a))
+    return constructorof_nameddims(typeof(a))(a, nameddimsindices)
+  end
   # TODO: Check the shape of `nameddimsindices` matches the shape of `a`.
   arrtype = mapreduce(nameddimsarraytype, combine_nameddimsarraytype, nameddimsindices)
   return arrtype(a, to_nameddimsindices(a, nameddimsindices))
@@ -781,7 +784,7 @@ function set_promote_shape(
   ax1::Tuple{AbstractNamedUnitRange,Vararg{AbstractNamedUnitRange,N}},
   ax2::Tuple{AbstractNamedUnitRange,Vararg{AbstractNamedUnitRange,N}},
 ) where {N}
-  perm = getperm(ax1, ax2)
+  perm = getperm(ax2, ax1)
   ax2_aligned = map(i -> ax2[i], perm)
   ax_promoted = promote_shape(dename.(ax1), dename.(ax2_aligned))
   return named.(ax_promoted, name.(ax1))
@@ -813,7 +816,7 @@ function set_check_broadcast_shape(
   ax1::Tuple{AbstractNamedUnitRange,Vararg{AbstractNamedUnitRange,N}},
   ax2::Tuple{AbstractNamedUnitRange,Vararg{AbstractNamedUnitRange,N}},
 ) where {N}
-  perm = getperm(ax1, ax2)
+  perm = getperm(ax2, ax1)
   ax2_aligned = map(i -> ax2[i], perm)
   check_broadcast_shape(dename.(ax1), dename.(ax2_aligned))
   return nothing

src/tensoralgebra.jl

@@ -29,7 +29,10 @@ function TensorAlgebra.contract(
   a_dest, nameddimsindices_dest = contract(
     dename(a1), nameddimsindices(a1), dename(a2), nameddimsindices(a2), α
   )
-  return nameddims(a_dest, nameddimsindices_dest)
+  nameddimstype = combine_nameddimsarraytype(
+    constructorof(typeof(a1)), constructorof(typeof(a2))
+  )
+  return nameddimstype(a_dest, nameddimsindices_dest)
 end
 
 function Base.:*(a1::AbstractNamedDimsArray, a2::AbstractNamedDimsArray)