Rename to NullBroadcasts + NullBroadcasted

NEWS.md

@@ -1,4 +1,4 @@
-AbsentTypes.jl Release Notes
+NullBroadcasts.jl Release Notes
 ============================
 
 Main

Project.toml

@@ -1,4 +1,4 @@
-name = "AbsentTypes"
+name = "NullBroadcasts"
 uuid = "0d71be07-595a-4f89-9529-4065a4ab43a6"
 authors = ["CliMA Contributors <clima-software@caltech.edu>"]
 version = "0.1.0"

README.md

@@ -1,2 +1,3 @@
-# AbsentTypes.jl
-A small package for defining absent (i.e., null) types and behaviors
+# NullBroadcasts.jl
+
+A small package for defining null broadcasted types and behaviors

docs/Project.toml

@@ -1,4 +1,4 @@
 [deps]
 Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 DocumenterCitations = "daee34ce-89f3-4625-b898-19384cb65244"
-AbsentTypes = "0d71be07-595a-4f89-9529-4065a4ab43a6"
+NullBroadcasts = "0d71be07-595a-4f89-9529-4065a4ab43a6"

docs/make.jl

@@ -1,5 +1,5 @@
 import Documenter, DocumenterCitations
-import AbsentTypes
+import NullBroadcasts
 
 bib = DocumenterCitations.CitationBibliography(joinpath(@__DIR__, "refs.bib"))
 
@@ -15,17 +15,17 @@ format = Documenter.HTML(
 
 Documenter.makedocs(;
     plugins = [bib],
-    sitename = "AbsentTypes.jl",
+    sitename = "NullBroadcasts.jl",
     format = format,
     checkdocs = :exports,
     clean = true,
     doctest = true,
-    modules = [AbsentTypes],
+    modules = [NullBroadcasts],
     pages = Any["Home"=>"index.md", "API"=>"api.md", "References"=>"references.md"],
 )
 
 Documenter.deploydocs(
-    repo = "github.com/CliMA/AbsentTypes.jl.git",
+    repo = "github.com/CliMA/NullBroadcasts.jl.git",
     target = "build",
     push_preview = true,
     devbranch = "main",

docs/src/index.md

@@ -1,2 +1,2 @@
-# AbsentTypes.jl
+# NullBroadcasts.jl
 

src/NullBroadcasts.jl

@@ -0,0 +1,81 @@
+module NullBroadcasts
+
+"""
+    NullBroadcasted()
+
+A `Base.AbstractBroadcasted` that represents arithmetic object.
+
+An `NullBroadcasted()` can be added to, subtracted from, or multiplied by any value in a
+broadcast expression without incurring a runtime performance penalty.
+
+For example, the following rules hold when broadcasting instances of `NullBroadcasted`:
+```
+1 + NullBroadcasted() == 1
+NullBroadcasted() + 1 == 1
+1 - NullBroadcasted() == 1
+1 * NullBroadcasted() == NullBroadcasted()
+1 / NullBroadcasted() == NullBroadcasted()
+ ```
+"""
+struct NullBroadcasted <: Base.AbstractBroadcasted end
+Base.broadcastable(x::NullBroadcasted) = x
+
+struct NullBroadcastedStyle <: Base.BroadcastStyle end
+Base.BroadcastStyle(::Type{<:NullBroadcasted}) = NullBroadcasted()
+
+# Specialize on AbstractArrayStyle to avoid ambiguities with AbstractBroadcasted.
+Base.BroadcastStyle(::NullBroadcasted, ::Base.Broadcast.AbstractArrayStyle) =
+    NullBroadcasted()
+Base.BroadcastStyle(::Base.Broadcast.AbstractArrayStyle, ::NullBroadcasted) =
+    NullBroadcasted()
+
+# Add another method to avoid ambiguity between the previous two.
+Base.BroadcastStyle(::NullBroadcasted, ::NullBroadcasted) = NullBroadcasted()
+
+broadcasted_sum(args) =
+    if isempty(args)
+        NullBroadcasted()
+    elseif length(args) == 1
+        args[1]
+    else
+        Base.broadcasted(+, args...)
+    end
+Base.broadcasted(::NullBroadcasted, ::typeof(+), args...) =
+    broadcasted_sum(filter(arg -> !(arg isa NullBroadcasted), args))
+
+Base.broadcasted(op::typeof(-), ::NullBroadcasted, arg) = Base.broadcasted(op, arg)
+Base.broadcasted(op::typeof(-), arg, ::NullBroadcasted) =
+    Base.broadcasted(Base.identity, arg)
+Base.broadcasted(op::typeof(-), a::NullBroadcasted) = NullBroadcasted()
+Base.broadcasted(op::typeof(-), a::NullBroadcasted, ::NullBroadcasted) =
+    Base.broadcasted(op, a)
+
+Base.broadcasted(op::typeof(+), ::NullBroadcasted, args...) = Base.broadcasted(op, args...)
+Base.broadcasted(op::typeof(+), arg, ::NullBroadcasted) = Base.broadcasted(op, arg)
+Base.broadcasted(op::typeof(+), a::NullBroadcasted, ::NullBroadcasted) =
+    Base.broadcasted(op, a)
+
+Base.broadcasted(op::typeof(*), ::NullBroadcasted, args...) = NullBroadcasted()
+Base.broadcasted(op::typeof(*), arg, ::NullBroadcasted) = NullBroadcasted()
+Base.broadcasted(op::typeof(*), ::NullBroadcasted, ::NullBroadcasted) = NullBroadcasted()
+Base.broadcasted(op::typeof(/), ::NullBroadcasted, args...) = NullBroadcasted()
+Base.broadcasted(op::typeof(/), arg, ::NullBroadcasted) = NullBroadcasted()
+Base.broadcasted(op::typeof(/), ::NullBroadcasted, ::NullBroadcasted) = NullBroadcasted()
+
+function skip_materialize(dest, bc::Base.Broadcast.Broadcasted)
+    if typeof(bc.f) <: typeof(+) || typeof(bc.f) <: typeof(-)
+        if length(bc.args) == 2 &&
+           bc.args[1] === dest &&
+           bc.args[2] === Base.Broadcast.Broadcasted(NullBroadcasted, ())
+            return true
+        else
+            return false
+        end
+    else
+        return false
+    end
+end
+
+Base.Broadcast.instantiate(bc::Base.Broadcast.Broadcasted{NullBroadcastedStyle}) = x
+
+end # module NullBroadcasts

test/runtests.jl

@@ -3,15 +3,15 @@ julia --project
 using Revise; using TestEnv; TestEnv.activat(); include("test/runtests.jl")
 =#
 using Test
-using AbsentTypes
-using AbsentTypes: Absent
+using NullBroadcasts
+using NullBroadcasts: NullBroadcasted
 using Aqua
 using LazyBroadcast: lazy
 import Base.Broadcast: instantiate, materialize, Broadcasted, DefaultArrayStyle
 
-@testset "Absent" begin
+@testset "NullBroadcasted" begin
     x = [1]
-    a = Absent()
+    a = NullBroadcasted()
     @test typeof(lazy.(x .+ a)) <: Broadcasted{
         DefaultArrayStyle{1},
         Tuple{Base.OneTo{Int64}},
@@ -24,8 +24,8 @@ import Base.Broadcast: instantiate, materialize, Broadcasted, DefaultArrayStyle
         typeof(+),
         Tuple{Vector{Int64}},
     }
-    @test lazy.(a .* x) isa Absent
-    @test lazy.(a ./ x) isa Absent
+    @test lazy.(a .* x) isa NullBroadcasted
+    @test lazy.(a ./ x) isa NullBroadcasted
 
     # +
     @test materialize(lazy.(a .+ x .+ 1)) == [2]
@@ -38,30 +38,30 @@ import Base.Broadcast: instantiate, materialize, Broadcasted, DefaultArrayStyle
     @test materialize(lazy.(a .- 1 .- x)) == [-2]
     @test materialize(lazy.(1 .- a .- x)) == [0]
     @test materialize(lazy.(1 .- x .- a)) == [0]
-    @test materialize(lazy.(a .- a)) == Absent()
+    @test materialize(lazy.(a .- a)) == NullBroadcasted()
     @test materialize(lazy.(1 .- 1 .+ a .- a)) == 0
     @test materialize(lazy.(x .- x .+ a .- a)) == [0]
 
     # *
-    @test materialize(lazy.(a .* x .* 1)) == Absent()
-    @test materialize(lazy.(a .* 1 .* x)) == Absent()
-    @test materialize(lazy.(1 .* a .* x)) == Absent()
-    @test materialize(lazy.(1 .* x .* a)) == Absent()
+    @test materialize(lazy.(a .* x .* 1)) == NullBroadcasted()
+    @test materialize(lazy.(a .* 1 .* x)) == NullBroadcasted()
+    @test materialize(lazy.(1 .* a .* x)) == NullBroadcasted()
+    @test materialize(lazy.(1 .* x .* a)) == NullBroadcasted()
 
     # /
-    @test materialize(lazy.(a ./ x ./ 1)) == Absent()
-    @test materialize(lazy.(a ./ 1 ./ x)) == Absent()
-    @test materialize(lazy.(1 ./ a ./ x)) == Absent()
-    @test materialize(lazy.(1 ./ x ./ a)) == Absent()
+    @test materialize(lazy.(a ./ x ./ 1)) == NullBroadcasted()
+    @test materialize(lazy.(a ./ 1 ./ x)) == NullBroadcasted()
+    @test materialize(lazy.(1 ./ a ./ x)) == NullBroadcasted()
+    @test materialize(lazy.(1 ./ x ./ a)) == NullBroadcasted()
 
-    @test_throws MethodError Absent() + 1
-    @test_throws MethodError Absent() - 1
-    @test_throws MethodError Absent() * 1
-    @test_throws MethodError Absent() / 1
+    @test_throws MethodError NullBroadcasted() + 1
+    @test_throws MethodError NullBroadcasted() - 1
+    @test_throws MethodError NullBroadcasted() * 1
+    @test_throws MethodError NullBroadcasted() / 1
 
-    @test materialize(Absent()) isa Absent
+    @test materialize(NullBroadcasted()) isa NullBroadcasted
 end
 
 @testset "Aqua" begin
-    Aqua.test_all(AbsentTypes)
+    Aqua.test_all(NullBroadcasts)
 end