Add more BlockTensorMap constructors

src/tensors/blocktensor.jl

@@ -53,6 +53,51 @@ function BlockTensorMap{TT}(
     return BlockTensorMap{TT}(data, codom ← dom)
 end
 
+function BlockTensorMap(
+    f::Union{UndefInitializer,UndefBlocksInitializer}, space::TensorMapSumSpace{S,N₁,N₂}
+) where {S,N₁,N₂}
+    TT = tensormaptype(S, N₁, N₂, Float64)
+    return BlockTensorMap{TT}(f, space)
+end
+function BlockTensorMap(
+    f::Union{UndefInitializer,UndefBlocksInitializer},
+    codom::ProductSumSpace,
+    dom::ProductSumSpace,
+)
+    return BlockTensorMap(f, codom ← dom)
+end
+
+function BlockTensorMap(
+    data::Array{TT}, space::TensorMapSumSpace{S,N₁,N₂}
+) where {S,N₁,N₂,TT<:AbstractTensorMap{<:Any,S,N₁,N₂}}
+    return BlockTensorMap{TT}(data, space)
+end
+function BlockTensorMap(
+    data::Array{<:AbstractTensorMap}, codom::ProductSumSpace, dom::ProductSumSpace
+)
+    return BlockTensorMap(data, codom ← dom)
+end
+
+# AbstractBlockTensorMap -> BlockTensorMap
+function BlockTensorMap(t::AbstractBlockTensorMap)
+    t isa BlockTensorMap && return t # TODO: should this copy?
+    tdst = BlockTensorMap{eltype(t)}(undef_blocks, space(t))
+    for I in eachindex(t)
+        tdst[I] = t[I]
+    end
+    return tdst
+end
+
+# AbstractTensorMap -> BlockTensorMap
+function BlockTensorMap(t::AbstractTensorMap, space::TensorMapSumSpace)
+    TT = tensormaptype(spacetype(t), numout(t), numin(t), storagetype(t))
+    tdst = BlockTensorMap{TT}(undef, space)
+    for (f₁, f₂) in fusiontrees(tdst)
+        tdst[f₁, f₂] .= t[f₁, f₂]
+    end
+    return tdst
+end
+
 # Convenience constructors
 # ------------------------
 for (fname, felt) in ((:zeros, :zero), (:ones, :one))
@@ -85,15 +130,6 @@ for randfun in (:rand, :randn, :randexp)
     end
 end
 
-function BlockTensorMap(t::AbstractBlockTensorMap)
-    t isa BlockTensorMap && return t # TODO: should this copy?
-    tdst = BlockTensorMap{eltype(t)}(undef_blocks, codomain(t), domain(t))
-    for I in eachindex(t)
-        tdst[I] = t[I]
-    end
-    return tdst
-end
-
 # Properties
 # ----------
 Base.eltype(::Type{<:BlockTensorMap{TT}}) where {TT} = TT