fixup! feat: support callable parameters

Author: AayushSabharwal

test/split_parameters.jl

@@ -6,6 +6,7 @@ using ModelingToolkit: t_nounits as t, D_nounits as D
 using ModelingToolkit: MTKParameters, ParameterIndex, NONNUMERIC_PORTION
 using SciMLStructures: Tunable, Discrete, Constants
 using StaticArrays: SizedVector
+using SymbolicIndexingInterface: is_parameter
 
 x = [1, 2.0, false, [1, 2, 3], Parameter(1.0)]
 
@@ -229,11 +230,13 @@ end
     @mtkbuild sys = ODESystem(D(x) ~ fn(x), t, [x], [fn])
     @test is_parameter(sys, fn)
     @test ModelingToolkit.defaults(sys)[fn] == _f1
+
     prob = ODEProblem(sys, [x => 1.0], (0.0, 1.0))
     @test_broken @inferred prob.ps[fn]
     @test_broken @inferred prob.f(prob.u0, prob.p, prob.tspan[1])
     sol = solve(prob; abstol = 1e-10, reltol = 1e-10)
     @test sol.u[end][] ≈ exp(2.0)
+
     prob = ODEProblem(sys, [x => 1.0], (0.0, 1.0), [fn => Foo()])
     @test_broken @inferred prob.ps[fn]
     @test_broken @inferred prob.f(prob.u0, prob.p, prob.tspan[1])