Three-dimensional indexing of parameters with Colon() doesn't work

[1-Bart-1]

Describe the bug 🐞

When attempting to access a slice of a 3D array declared as a @parameter, an ArgumentError is thrown due to an invalid index type. This works fine with a 2D array.

Minimal Reproducible Example 👇

using ModelingToolkit
nx = 3
ny = 10

@parameters two_dims[1:nx, 1:ny] = zeros(nx,ny)
@show two_dims[1,:]

@parameters three_dims[1, 1:nx, 1:ny]
@show three_dims[1,1,1] # works
@show three_dims[1,1,:] # works
@show three_dims[1,:,:] # works

@parameters three_dims[1, 1:nx, 1:ny] = zeros(1,nx,ny)
@show three_dims[1,1,1] # works
@show three_dims[1,1,:] # doesn't work
@show three_dims[1,:,:] # doesn't work

Output

two_dims[1, :] = (two_dims[1, Colon()])[1:10]
three_dims[1, 1, 1] = three_dims[1, 1, 1]
three_dims[1, 1, :] = (three_dims[1, 1, Colon()])[1:10]
three_dims[1, :, :] = (three_dims[1, Colon(), Colon()])[1:3,1:10]
three_dims[1, 1, 1] = three_dims[1, 1, 1]
ERROR: LoadError: ArgumentError: invalid index: k of type SymbolicUtils.BasicSymbolic{Int64}
Stacktrace:
  [1] to_index(i::SymbolicUtils.BasicSymbolic{Int64})
    @ Base ./indices.jl:315
  [2] to_index(A::Array{Float64, 3}, i::SymbolicUtils.BasicSymbolic{Int64})
    @ Base ./indices.jl:292
  [3] to_indices (repeats 3 times)
    @ ./indices.jl:368 [inlined]
  [4] to_indices
    @ ./indices.jl:359 [inlined]
  [5] getindex(::Array{Float64, 3}, ::Int64, ::Int64, ::SymbolicUtils.BasicSymbolic{Int64})
    @ Base ./abstractarray.jl:1312
  [6] (::Symbolics.var"#229#231"{DataType})(::SymbolicUtils.BasicSymbolic{Real}, ::SymbolicUtils.BasicSymbolic{Array{Real, 3}}, ::Int64, ::Vararg{Any})
    @ Symbolics ~/.julia/packages/Symbolics/JCopU/src/variable.jl:39
  [7] getindex(::SymbolicUtils.BasicSymbolic{Array{Real, 3}}, ::Int64, ::Int64, ::SymbolicUtils.BasicSymbolic{Int64})
    @ Symbolics ~/.julia/packages/Symbolics/JCopU/src/array-lib.jl:86
  [8] getindex(::SymbolicUtils.BasicSymbolic{Array{Real, 3}}, ::Int64, ::Int64, ::Function)
    @ Symbolics ~/.julia/packages/Symbolics/JCopU/src/array-lib.jl:76
  [9] getindex(::Symbolics.Arr{Num, 3}, ::Int64, ::Int64, ::Function)
    @ Symbolics ~/.julia/packages/Symbolics/JCopU/src/array-lib.jl:94
 [10] macro expansion
    @ show.jl:1232 [inlined]
 [11] top-level scope
    @ ~/Code/MWE/mwe/weird_params.jl:15
 [12] include(fname::String)
    @ Main ./sysimg.jl:38
 [13] top-level scope
    @ REPL[3]:1
in expression starting at /home/bart/Code/MWE/mwe/weird_params.jl:15

Mtk version

  [961ee093] ModelingToolkit v10.2.0

julia> versioninfo()
Julia Version 1.11.5
Commit 760b2e5b739 (2025-04-14 06:53 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 16 × Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
  WORD_SIZE: 64
  LLVM: libLLVM-16.0.6 (ORCJIT, skylake)
Threads: 16 default, 0 interactive, 8 GC (on 16 virtual cores)
Environment:
  JULIA_PKG_SERVER_REGISTRY_PREFERENCE = eager
  LD_LIBRARY_PATH = /usr/local/cuda-12.2/lib64