Don't throw custom errors for ops on NoLogAbsDetJacobian

Author: oschulz

src/with_ladj.jl

@@ -14,8 +14,8 @@ For `(y, ladj) = with_logabsdet_jacobian(f, x)`, the following must hold true:
 `with_logabsdet_jacobian` comes with support for broadcasted/mapped functions
 (via `Base.Fix1`) and (Julia >=v1.6 only) `ComposedFunction`.
 
-If no volume element is defined/applicable, `with_logabsdet_jacobian(f, x)` returns
-[`NoLogAbsDetJacobian(f)`](@ref).
+If no volume element is defined/applicable, `with_logabsdet_jacobian(f::F, x::T)`
+returns [`NoLogAbsDetJacobian{F,T}(f)`](@ref).
 
 # Examples
 
@@ -83,15 +83,6 @@ struct NoLogAbsDetJacobian{F,T}
 end
 export NoLogAbsDetJacobian
 
-function _no_ladj_errmsg(@nospecialize noladj::NoLogAbsDetJacobian{F,T}) where {F,T}
-    ("with_logabsdet_jacobian(", noladj.f, ", ::", T, " is not defined ")
-end
-
-Base.getindex(@nospecialize(noladj::NoLogAbsDetJacobian), args...) = error(_no_ladj_errmsg(noladj)...)
-Base.iterate(@nospecialize(noladj::NoLogAbsDetJacobian)) = error(_no_ladj_errmsg(noladj)...)
-Base.firstindex(@nospecialize(noladj::NoLogAbsDetJacobian)) = error(_no_ladj_errmsg(noladj)...)
-Base.lastindex(@nospecialize(noladj::NoLogAbsDetJacobian)) = error(_no_ladj_errmsg(noladj)...)
-
 with_logabsdet_jacobian(f::F, ::T) where {F,T} = NoLogAbsDetJacobian{F,T}(f, )
 
 

test/test_with_ladj.jl

@@ -14,14 +14,7 @@ include("getjacobian.jl")
 
 @testset "with_logabsdet_jacobian" begin
     @test with_logabsdet_jacobian(sum, rand(5)) == NoLogAbsDetJacobian{typeof(sum),Vector{Float64}}(sum)
-    noladj = with_logabsdet_jacobian(sum, rand(5))
-    @test_throws ErrorException noladj[1]
-    @test_throws ErrorException noladj[2]
-    @test_throws ErrorException firstindex(noladj)
-    @test_throws ErrorException lastindex(noladj)
-    @test_throws ErrorException first(noladj)
-    @test_throws ErrorException last(noladj)
-    @test_throws ErrorException _, _ = noladj
+    @test_throws MethodError _, _ = with_logabsdet_jacobian(sum, rand(5))
 
     function ChangesOfVariables.with_logabsdet_jacobian(::typeof(foo), x)
         y = foo(x)