Merge pull request #129 from SciML/undef_init

add an undef initializer for LArray

Author: ChrisRackauckas

Project.toml

@@ -1,7 +1,7 @@
 name = "LabelledArrays"
 uuid = "2ee39098-c373-598a-b85f-a56591580800"
 authors = ["Chris Rackauckas <[email protected]>"]
-version = "1.12.0"
+version = "1.12.1"
 
 [deps]
 ArrayInterfaceCore = "30b0a656-2188-435a-8636-2ec0e6a096e2"

src/LabelledArrays.jl

@@ -59,11 +59,15 @@ end
 Base.NamedTuple(x::Union{LArray, SLArray}) = NamedTuple{symnames(typeof(x))}(x.__x)
 @inline Base.reshape(a::SLArray, s::Size) = StaticArrays.similar_type(a, s)(Tuple(a))
 
-function ArrayInterfaceCore.ismutable(::Type{<:LArray{T, N, Syms}}) where {T, N, Syms}
+function ArrayInterfaceCore.ismutable(::Type{<:LArray{T, N, D, Syms}}) where {T, N, D, Syms}
     ArrayInterfaceCore.ismutable(T)
 end
 ArrayInterfaceCore.can_setindex(::Type{<:SLArray}) = false
 
+function ArrayInterfaceCore.undefmatrix(x::LArray{T, N, D, Syms}) where {T, N, D, Syms}
+    similar(x.__x, length(Syms), length(Syms))
+end
+
 function PreallocationTools.get_tmp(dc::PreallocationTools.DiffCache,
                                     u::LArray{T, N, D, Syms}) where {T <: ForwardDiff.Dual,
                                                                      N, D, Syms}

src/larray.jl

@@ -4,6 +4,11 @@ struct LArray{T, N, D <: AbstractArray{T, N}, Syms} <: DenseArray{T, N}
     LArray{T, N, D, Syms}(__x) where {T, N, D, Syms} = new{T, N, D, Syms}(__x)
 end
 
+function LArray{T, N, D, Syms}(::UndefInitializer, n::Int64) where {T, N, D, Syms}
+    @assert length(Syms) == n
+    LArray{T, N, D, Syms}(similar(D, n))
+end
+
 #####################################
 # NamedTuple compatibility
 #####################################
@@ -199,8 +204,8 @@ A.a == 1
 ```
 
 Users can also generate a labelled array with undefined values by instead giving
-the dimensions. This approach is useful if the user intends to pre-allocate an 
-array for some later input. 
+the dimensions. This approach is useful if the user intends to pre-allocate an
+array for some later input.
 
 ```julia
 A = @LArray Float64 (2,2) (:a,:b,:c,:d)
@@ -226,7 +231,7 @@ julia> z.a
  4
 ```
 
-The labels of LArray and SLArray can be accessed 
+The labels of LArray and SLArray can be accessed
 by function `symbols`, which returns a tuple of symbols.
 """
 macro LArray(vals, syms)
@@ -260,7 +265,7 @@ A = @LVector Float64 (:a,:b,:c,:d)
 A .= rand(4)
 ```
 
-On the other hand, users can also initialize the vector and set its values at the 
+On the other hand, users can also initialize the vector and set its values at the
 same time:
 
 ```julia

test/larrays.jl

@@ -14,6 +14,7 @@ using LabelledArrays, Test, InteractiveUtils
     mat = rand(4, 3)
     @test mat * vals ≈ mat * [1.0, 2.0, 3.0]
     syms = (:a, :b, :c)
+    @test typeof(typeof(x)(undef, 3)) == typeof(x)
 
     for (i, s) in enumerate(syms)
         @show i, s