Add region(::Plan) for accessing transformed region

Project.toml

@@ -1,6 +1,6 @@
 name = "AbstractFFTs"
 uuid = "621f4979-c628-5d54-868e-fcf4e3e8185c"
-version = "1.1.0"
+version = "1.2.0"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"

src/definitions.jl

@@ -15,6 +15,18 @@ size(p::Plan, d) = size(p)[d]
 ndims(p::Plan) = length(size(p))
 length(p::Plan) = prod(size(p))::Int
 
+"""
+    region(p::Plan)
+
+Return an iterable of the dimensions that are transformed by the FFT plan `p`.
+
+# Implementation
+
+The default definition of `region` returns `p.region`.
+Hence this method should be implemented only for types of `Plan`s that do not store the transformed region in a field of name `region`.
+"""
+region(p::Plan) = p.region
+
 fftfloat(x) = _fftfloat(float(x))
 _fftfloat(::Type{T}) where {T<:BlasReal} = T
 _fftfloat(::Type{Float16}) = Float32
@@ -243,6 +255,8 @@ ScaledPlan(p::ScaledPlan, α::Number) = ScaledPlan(p.p, p.scale * α)
 
 size(p::ScaledPlan) = size(p.p)
 
+region(p::ScaledPlan) = region(p.p)
+
 show(io::IO, p::ScaledPlan) = print(io, p.scale, " * ", p.p)
 summary(p::ScaledPlan) = string(p.scale, " * ", summary(p.p))
 

test/runtests.jl

@@ -60,18 +60,21 @@ end
         @test eltype(P) === ComplexF64
         @test P * x ≈ fftw_fft
         @test P \ (P * x) ≈ x
+        @test AbstractFFTs.region(P) == dims
 
         fftw_bfft = complex.(size(x, dims) .* x)
         @test AbstractFFTs.bfft(y, dims) ≈ fftw_bfft
         P = plan_bfft(x, dims)
         @test P * y ≈ fftw_bfft
         @test P \ (P * y) ≈ y
+        @test AbstractFFTs.region(P) == dims
 
         fftw_ifft = complex.(x)
         @test AbstractFFTs.ifft(y, dims) ≈ fftw_ifft
         P = plan_ifft(x, dims)
         @test P * y ≈ fftw_ifft
         @test P \ (P * y) ≈ y
+        @test AbstractFFTs.region(P) == dims
 
         # real FFT
         fftw_rfft = fftw_fft[
@@ -84,18 +87,21 @@ end
         @test eltype(P) === Int
         @test P * x ≈ fftw_rfft
         @test P \ (P * x) ≈ x
+        @test AbstractFFTs.region(P) == dims
 
         fftw_brfft = complex.(size(x, dims) .* x)
         @test AbstractFFTs.brfft(ry, size(x, dims), dims) ≈ fftw_brfft
         P = plan_brfft(ry, size(x, dims), dims)
         @test P * ry ≈ fftw_brfft
         @test P \ (P * ry) ≈ ry
+        @test AbstractFFTs.region(P) == dims
 
         fftw_irfft = complex.(x)
         @test AbstractFFTs.irfft(ry, size(x, dims), dims) ≈ fftw_irfft
         P = plan_irfft(ry, size(x, dims), dims)
         @test P * ry ≈ fftw_irfft
         @test P \ (P * ry) ≈ ry
+        @test AbstractFFTs.region(P) == dims
     end
 end
 
@@ -170,7 +176,7 @@ end
     # normalization should be inferable even if region is only inferred as ::Any,
     # need to wrap in another function to test this (note that p.region::Any for
     # p::TestPlan)
-    f9(p::Plan{T}, sz) where {T} = AbstractFFTs.normalization(real(T), sz, p.region)
+    f9(p::Plan{T}, sz) where {T} = AbstractFFTs.normalization(real(T), sz, region(p))
     @test @inferred(f9(plan_fft(zeros(10), 1), 10)) == 1/10
 end