Merge pull request #22 from eliascarv/type-stable-functional

Type Stable Functional

Author: juliohm

src/transforms/functional.jl

@@ -7,8 +7,8 @@
 
 The transform that applies a `function` elementwise.
 """
-struct Functional <: Colwise
-  func::Function
+struct Functional{F} <: Colwise
+  func::F
 end
 
 isrevertible(transform::Functional) =
@@ -23,7 +23,7 @@ inverse(::typeof(sin))  = asin
 inverse(::typeof(asin)) = sin
 
 # fallback to nothing
-inverse(::Function) = nothing
+inverse(::Any) = nothing
 
 colcache(::Functional, x) = nothing
 

test/runtests.jl

@@ -20,6 +20,13 @@ islinux = Sys.islinux()
 visualtests = !isCI || (isCI && islinux)
 datadir = joinpath(@__DIR__,"data")
 
+# for functor tests in Functional testset
+struct Polynomial{T<:Real}
+  coeffs::Vector{T}
+end
+Polynomial(args::T...) where {T<:Real} = Polynomial(collect(args))
+(p::Polynomial)(x) = sum(a * x^(i-1) for (i, a) in enumerate(p.coeffs))
+
 # list of tests
 testfiles = [
   "distributions.jl",

test/transforms.jl

@@ -358,6 +358,19 @@
     n, c = apply(T, t)
     @test t == n
     @test isrevertible(T) == false
+
+    # functor tests
+    x = rand(1500)
+    y = rand(1500)
+    t = Table(; x, y)
+    f = Polynomial(1, 2, 3) # f(x) = 1 + 2x + 3x²
+    T = Functional(f)
+    n, c = apply(T, t)
+    @test f.(x) == n.x
+    @test f.(y) == n.y
+    @test all(≥(1), n.x)
+    @test all(≥(1), n.y)
+    @test isrevertible(T) == false
   end
 
   @testset "EigenAnalysis" begin