Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Added a Scalar type for 0-dimensional array #50

Merged
merged 4 commits into from
Oct 12, 2016
Merged

Added a Scalar type for 0-dimensional array #50

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
13243f3
Added a `Scalar` type for 0-dimensional array
Oct 12, 2016
df69c1f
Tests for Scalar
Oct 12, 2016
f00c7f6
Docs for `Scalar`
Oct 12, 2016
bba07c3
Better integration of Scalar
Oct 12, 2016
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 20 additions & 0 deletions src/Scalar.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,20 @@
"""
Scalar{T}(x::T)

Construct a statically-sized 0-dimensional array that contains a single element,
`x`. This type is particularly useful for influencing broadcasting operations.
"""
immutable Scalar{T} <: StaticArray{T,0}
data::T
end

@inline (::Type{Scalar}){T}(x::Tuple{T}) = Scalar{T}(x[1])
Copy link

@TotalVerb TotalVerb Oct 12, 2016 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Doesn't this prevent scalarizing tuples? Can this maybe be a convert method instead?

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The StaticArrays interface requires a constructor that accepts a Tuple. I may have messed this up a little though.

(PS - side effect is small - it only does this for a one-tuple which is scalar-like anyway).

Copy link

@TotalVerb TotalVerb Oct 12, 2016 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This code looks like it's preventing scalarizing any tuple, though.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I got caught up on this too, but I think I'm ok after reading Andy's comment - Tuple{T} being the tuple containing exactly one T (as quite distinct from Array{T} containing many T).

Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Ah right. The new version does not have the issue with even tuples containing one T though, which is even better 😄.


@pure size(::Type{Scalar}) = ()
@pure size{T}(::Type{Scalar{T}}) = ()

@inline function getindex(v::Scalar)
Copy link

@TotalVerb TotalVerb Oct 12, 2016 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Are these @inline annotations actually needed? Also, this function can probably be defined as getindex(v::Scalar) = v.data.

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

As a rule I haven't been trusting the heuristics of the compiler anywhere (at times a very large amount of code is inlined). But in this case you are right, I think it will always work.

v.data
end

@inline Tuple(v::Scalar) = (v.data,)
5 changes: 3 additions & 2 deletions src/StaticArrays.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -8,8 +8,8 @@ import Base: @pure, @propagate_inbounds, getindex, setindex!, size, similar,
ones, zeros, eye, cross, vecdot, reshape, fill, fill!, det, inv,
eig, trace, vecnorm, dot

export StaticArray, StaticVector, StaticMatrix
export SArray, SVector, SMatrix
export StaticScalar, StaticArray, StaticVector, StaticMatrix
export Scalar, SArray, SVector, SMatrix
export MArray, MVector, MMatrix
export FieldVector, MutableFieldVector

Expand All @@ -21,6 +21,7 @@ export similar_type
include("util.jl")

include("core.jl")
include("Scalar.jl")
include("SVector.jl")
include("FieldVector.jl")
include("SMatrix.jl")
Expand Down
3 changes: 3 additions & 0 deletions src/abstractarray.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,4 +1,7 @@
typealias StaticScalar{T} StaticArray{T,0}

@pure length{T<:StaticArray}(a::Union{T,Type{T}}) = prod(size(a))
@pure length{T<:StaticScalar}(a::Union{T,Type{T}}) = 1

@pure function size{T<:StaticArray}(a::Union{T,Type{T}}, d::Integer)
s = size(a)
Expand Down