reorganize slightly and add FixedSizeBitArray

Author: oscarddssmith

src/FixedSizeArray.jl

@@ -0,0 +1,289 @@
+
+"""
+    Internal()
+
+Implementation detail. Do not use.
+"""
+struct Internal end
+
+struct FixedSizeArray{T,N,Mem<:GenericMemory{<:Any,T}} <: DenseArray{T,N}
+    mem::Mem
+    size::NTuple{N,Int}
+    function FixedSizeArray{T,N,M}(::Internal, mem::M, size::NTuple{N,Int}) where {T,N,M<:GenericMemory{<:Any,T}}
+        new{T,N,M}(mem, size)
+    end
+end
+
+function Base.propertynames(
+    # the `unused` is here because of https://github.com/JuliaLang/julia/issues/44428
+    (@nospecialize unused::FixedSizeArray),
+    ::Bool = false,
+)
+    ()
+end
+
+const FixedSizeVector{T} = FixedSizeArray{T,1}
+const FixedSizeMatrix{T} = FixedSizeArray{T,2}
+
+const default_underlying_storage_type = Memory
+
+function FixedSizeArray{T,N,V}(::UndefInitializer, size::NTuple{N,Int}) where {T,N,V}
+    FixedSizeArray{T,N,V}(Internal(), V(undef, checked_dims(size))::V, size)
+end
+function FixedSizeArray{T,N,V}(::UndefInitializer, size::NTuple{N,Integer}) where {T,N,V}
+    ints = map(Int, size)::NTuple{N,Int}  # prevent infinite recursion
+    FixedSizeArray{T,N,V}(undef, ints)
+end
+function FixedSizeArray{T,N,V}(::UndefInitializer, size::Vararg{Integer,N}) where {T,N,V}
+    FixedSizeArray{T,N,V}(undef, size)
+end
+function FixedSizeArray{T,<:Any,V}(::UndefInitializer, size::NTuple{N,Integer}) where {T,N,V}
+    FixedSizeArray{T,N,V}(undef, size)
+end
+function FixedSizeArray{T,<:Any,V}(::UndefInitializer, size::Vararg{Integer,N}) where {T,N,V}
+    FixedSizeArray{T,N,V}(undef, size)
+end
+function FixedSizeArray{T,N}(::UndefInitializer, size::NTuple{N,Integer}) where {T,N}
+    FixedSizeArray{T,N,default_underlying_storage_type{T}}(undef, size)
+end
+function FixedSizeArray{T,N}(::UndefInitializer, size::Vararg{Integer,N}) where {T,N}
+    FixedSizeArray{T,N}(undef, size)
+end
+function FixedSizeArray{T}(::UndefInitializer, size::Vararg{Integer,N}) where {T,N}
+    FixedSizeArray{T,N}(undef, size)
+end
+function FixedSizeArray{T}(::UndefInitializer, size::NTuple{N,Integer}) where {T,N}
+    FixedSizeArray{T,N}(undef, size)
+end
+
+Base.IndexStyle(::Type{<:FixedSizeArray}) = IndexLinear()
+Base.@propagate_inbounds Base.getindex(A::FixedSizeArray, i::Int) = A.mem[i]
+Base.@propagate_inbounds Base.@assume_effects :noub_if_noinbounds function Base.setindex!(A::FixedSizeArray{T}, x, i::Int) where {T}
+    @boundscheck checkbounds(A, i)
+    @inbounds A.mem[i] = x
+    return A
+end
+
+Base.size(a::FixedSizeArray) = a.size
+
+function Base.similar(::T, ::Type{E}, size::NTuple{N,Int}) where {T<:FixedSizeArray,E,N}
+    with_replaced_parameters(DenseArray, T, Val(E), Val(N))(undef, size)
+end
+
+Base.isassigned(a::FixedSizeArray, i::Int) = isassigned(a.mem, i)
+
+# safe product of a tuple of integers, for calculating dimensions size
+
+checked_dims_impl(a::Int, ::Tuple{}, have_overflow::Bool) = (a, have_overflow)
+function checked_dims_impl(a::Int, t::Tuple{Int,Vararg{Int,N}}, have_overflow::Bool) where {N}
+    b = first(t)
+    (m, o) = Base.Checked.mul_with_overflow(a, b)
+    r = Base.tail(t)::NTuple{N,Int}
+    checked_dims_impl(m, r, have_overflow | o)::Tuple{Int,Bool}
+end
+
+checked_dims(::Tuple{}) = 1
+function checked_dims(t::Tuple{Int,Vararg{Int,N}}) where {N}
+    any_is_zero     = any(iszero,                 t)::Bool
+    any_is_negative = any((x -> x < false),       t)::Bool
+    any_is_typemax  = any((x -> x == typemax(x)), t)::Bool
+    a = first(t)
+    r = Base.tail(t)::NTuple{N,Int}
+    (product, have_overflow) = checked_dims_impl(a, r, false)::Tuple{Int,Bool}
+    if any_is_negative
+        throw(ArgumentError("array dimension size can't be negative"))
+    end
+    if any_is_typemax
+        throw(ArgumentError("array dimension size can't be the maximum representable value"))
+    end
+    if have_overflow & !any_is_zero
+        throw(ArgumentError("array dimensions too great, can't represent length"))
+    end
+    product
+end
+
+# broadcasting
+
+function Base.BroadcastStyle(::Type{T}) where {T<:FixedSizeArray}
+    Broadcast.ArrayStyle{stripped_type(DenseArray, T)}()
+end
+
+function Base.similar(
+    bc::Broadcast.Broadcasted{Broadcast.ArrayStyle{S}},
+    ::Type{E},
+) where {S<:FixedSizeArray,E}
+    similar(S{E}, axes(bc))
+end
+
+# helper functions
+
+normalized_type(::Type{T}) where {T} = T
+
+function stripped_type_unchecked(::Type{DenseVector}, ::Type{<:GenericMemory{K,<:Any,AS}}) where {K,AS}
+    GenericMemory{K,<:Any,AS}
+end
+
+Base.@assume_effects :consistent function stripped_type_unchecked(
+    ::Type{DenseArray}, ::Type{<:FixedSizeArray{<:Any,<:Any,V}},
+) where {V}
+    U = stripped_type(DenseVector, V)
+    FixedSizeArray{E,N,U{E}} where {E,N}
+end
+
+function stripped_type(::Type{T}, ::Type{S}) where {T,S<:T}
+    ret = stripped_type_unchecked(T, S)::Type{<:T}::UnionAll
+    S::Type{<:ret}
+    normalized_type(ret)  # ensure `UnionAll` type variable order is normalized
+end
+
+function with_replaced_parameters(::Type{T}, ::Type{S}, ::Val{P1}, ::Val{P2}) where {T,S<:T,P1,P2}
+    t = T{P1,P2}::Type{<:T}
+    s = stripped_type(T, S)
+    S::Type{<:s}
+    s{P1,P2}::Type{<:s}::Type{<:T}::Type{<:t}
+end
+
+dimension_count_of(::Base.SizeUnknown) = 1
+dimension_count_of(::Base.HasLength) = 1
+dimension_count_of(::Base.HasShape{N}) where {N} = convert(Int, N)::Int
+
+struct LengthIsUnknown end
+struct LengthIsKnown end
+length_status(::Base.SizeUnknown) = LengthIsUnknown()
+length_status(::Base.HasLength) = LengthIsKnown()
+length_status(::Base.HasShape) = LengthIsKnown()
+
+function check_count_value(n::Int)
+    if n < 0
+        throw(ArgumentError("count can't be negative"))
+    end
+end
+function check_count_value(n)
+    throw(ArgumentError("count must be an `Int`"))
+end
+
+# TODO: use `SpecFSA` for implementing each `FixedSizeArray` constructor?
+struct SpecFSA{N,Mem<:GenericMemory} end
+function fsa_spec_from_type(::Type{FixedSizeArray})
+    SpecFSA{nothing,default_underlying_storage_type}()
+end
+function fsa_spec_from_type(::Type{FixedSizeArray{<:Any,M}}) where {M}
+    check_count_value(M)
+    SpecFSA{M,default_underlying_storage_type}()
+end
+function fsa_spec_from_type(::Type{FixedSizeArray{E}}) where {E}
+    E::Type
+    SpecFSA{nothing,default_underlying_storage_type{E}}()
+end
+function fsa_spec_from_type(::Type{FixedSizeArray{E,M}}) where {E,M}
+    check_count_value(M)
+    E::Type
+    SpecFSA{M,default_underlying_storage_type{E}}()
+end
+function fsa_spec_from_type(::Type{FixedSizeArray{E,<:Any,V}}) where {E,V}
+    E::Type
+    V::Type{<:DenseVector{E}}
+    SpecFSA{nothing,V}()
+end
+function fsa_spec_from_type(::Type{FixedSizeArray{E,M,V}}) where {E,M,V}
+    check_count_value(M)
+    E::Type
+    V::Type{<:DenseVector{E}}
+    SpecFSA{M,V}()
+end
+for V ∈ (Memory, AtomicMemory)
+    T = FixedSizeArray{E,M,V{E}} where {E,M}
+    @eval begin
+        function fsa_spec_from_type(::Type{$T})
+            SpecFSA{nothing,$V}()
+        end
+        function fsa_spec_from_type(::Type{($T){<:Any,M}}) where {M}
+            check_count_value(M)
+            SpecFSA{M,$V}()
+        end
+    end
+end
+
+parent_type(::Type{<:FixedSizeArray{<:Any,<:Any,T}}) where {T} = T
+
+underlying_storage(m) = m
+underlying_storage(f::FixedSizeArray) = f.mem
+
+axes_are_one_based(axes) = all(isone ∘ first, axes)
+
+# converting constructors for copying other array types
+
+function FixedSizeArray{T,N,V}(src::AbstractArray{S,N}) where {T,N,V,S}
+    axs = axes(src)
+    if !axes_are_one_based(axs)
+        throw(DimensionMismatch("source array has a non-one-based indexing axis"))
+    end
+    # Can't use `Base.size` because, according to it's doc string, it's not
+    # available for all `AbstractArray` types.
+    size = map(length, axs)
+    dst = FixedSizeArray{T,N,V}(undef, size)
+    copyto!(dst.mem, src)
+    dst
+end
+
+FixedSizeArray{T,<:Any,V}(a::AbstractArray{<:Any,N}) where {V,T,N} = FixedSizeArray{T,N,V}(a)
+
+FixedSizeArray{T,N}(a::AbstractArray{<:Any,N}) where {T,N} = FixedSizeArray{T,N,default_underlying_storage_type{T}}(a)
+FixedSizeArray{T}(a::AbstractArray{<:Any,N})   where {T,N} = FixedSizeArray{T,N}(a)
+FixedSizeArray{<:Any,N}(a::AbstractArray{T,N}) where {T,N} = FixedSizeArray{T,N}(a)
+FixedSizeArray(a::AbstractArray{T,N})          where {T,N} = FixedSizeArray{T,N}(a)
+
+# conversion
+
+Base.convert(::Type{T}, a::T) where {T<:FixedSizeArray} = a
+Base.convert(::Type{T}, a::AbstractArray) where {T<:FixedSizeArray} = T(a)::T
+
+# `copyto!`
+
+Base.@propagate_inbounds function copyto5!(dst, doff, src, soff, n)
+    copyto!(underlying_storage(dst), doff, underlying_storage(src), soff, n)
+    dst
+end
+
+Base.@propagate_inbounds function copyto2!(dst, src)
+    copyto!(underlying_storage(dst), underlying_storage(src))
+    dst
+end
+
+Base.@propagate_inbounds Base.copyto!(dst::FixedSizeArray, doff::Integer, src::FixedSizeArray, soff::Integer, n::Integer) = copyto5!(dst, doff, src, soff, n)
+Base.@propagate_inbounds Base.copyto!(dst::FixedSizeArray, src::FixedSizeArray) = copyto2!(dst, src)
+
+for A ∈ (Array, GenericMemory)  # Add more? Too bad we have to hardcode to avoid ambiguity.
+    @eval begin
+        Base.@propagate_inbounds Base.copyto!(dst::FixedSizeArray, doff::Integer, src::$A,             soff::Integer, n::Integer) = copyto5!(dst, doff, src, soff, n)
+        Base.@propagate_inbounds Base.copyto!(dst::$A,             doff::Integer, src::FixedSizeArray, soff::Integer, n::Integer) = copyto5!(dst, doff, src, soff, n)
+
+        Base.@propagate_inbounds Base.copyto!(dst::FixedSizeArray, src::$A            ) = copyto2!(dst, src)
+        Base.@propagate_inbounds Base.copyto!(dst::$A,             src::FixedSizeArray) = copyto2!(dst, src)
+    end
+end
+
+# unsafe: the native address of the array's storage
+
+Base.cconvert(::Type{<:Ptr}, a::FixedSizeArray) = a.mem
+
+# `elsize`: part of the strided arrays interface, used for `pointer`
+
+Base.elsize(::Type{A}) where {A<:FixedSizeArray} = Base.elsize(parent_type(A))
+
+# `reshape`: specializing it to ensure it returns a `FixedSizeArray`
+
+function Base.reshape(a::FixedSizeArray{T,<:Any,V}, size::NTuple{N,Int}) where {V,T,N}
+    len = checked_dims(size)
+    if length(a) != len
+        throw(DimensionMismatch("new shape not consistent with existing array length"))
+    end
+    FixedSizeArray{T,N,V}(Internal(), a.mem, size)
+end
+
+if isdefined(Base, :dataids) && (Base.dataids isa Function)
+    # This is an internal, non-public function which is nevertheless needed to
+    # get good performance in some cases (e.g. broadcasting):
+    # <https://github.com/JuliaArrays/FixedSizeArrays.jl/issues/63>.
+    Base.dataids(a::FixedSizeArray) = Base.dataids(a.mem)
+end