Cheb2LegTH <: Plan (#234)

* Cheb2LegTH <: Plan

* avoid stack overflow in different sizes

Author: dlfivefifty

src/chebyshevtransform.jl

@@ -2,6 +2,8 @@
 
 abstract type ChebyshevPlan{T} <: Plan{T} end
 
+*(P::ChebyshevPlan{T}, x::AbstractArray{T}) where T = error("Plan applied to wrong size array")
+
 size(P::ChebyshevPlan) = isdefined(P, :plan) ? size(P.plan) : (0,)
 length(P::ChebyshevPlan) = isdefined(P, :plan) ? length(P.plan) : 0
 
@@ -151,6 +153,8 @@ end
     ldiv!(_prod_size(size(y), d), y)
 end
 
+
+
 function *(P::ChebyshevTransformPlan{T,1,K,true,N}, x::AbstractArray{T,N}) where {T,K,N}
     isempty(x) && return x
 

src/toeplitzhankel.jl

@@ -118,7 +118,7 @@ end
 
 
 
-struct ChebyshevToLegendrePlanTH{TH}
+struct ChebyshevToLegendrePlanTH{S,TH<:ToeplitzHankelPlan{S}} <: Plan{S}
     toeplitzhankel::TH
 end
 

test/chebyshevtests.jl

@@ -462,4 +462,9 @@ using FastTransforms, Test
             @test F \ (F*X) ≈ F * (F\X) ≈ X
         end
     end
+
+    @testset "incompatible shapes" begin
+        @test_throws ErrorException plan_chebyshevtransform(randn(5)) * randn(5,5)
+        @test_throws ErrorException plan_ichebyshevtransform(randn(5)) * randn(5,5)
+    end
 end