Respect positional arguments in @mtkmodel

src/systems/model_parsing.jl

@@ -945,15 +945,17 @@ end
 
 ### Parsing Components:
 
-function component_args!(a, b, varexpr, kwargs; index_name = nothing)
+function component_args!(a, b, varexpr, kwargs; index_name = nothing, keywords = false )
+ # keywords indicates if whether or not the keyword arg delimiter ; has been seen
  # Whenever `b` is a function call, skip the first arg aka the function name.
  # Whenever it is a kwargs list, include it.
  start = b.head == :call ? 2 : 1
+
  for i in start:lastindex(b.args)
  arg = b.args[i]
  arg isa LineNumberNode && continue
  MLStyle.@match arg begin
- x::Symbol || Expr(:kw, x) => begin
+ Expr(:kw, x) || (x::Symbol && if keywords end) => begin # handle keyword args
  varname, _varname = _rename(a, x)
  b.args[i] = Expr(:kw, x, _varname)
  push!(varexpr.args, :((if $varname !== nothing
@@ -967,8 +969,23 @@ function component_args!(a, b, varexpr, kwargs; index_name = nothing)
  push!(kwargs, Expr(:kw, varname, nothing))
  # dict[:kwargs][varname] = nothing
  end
+ x::Symbol && if !keywords end => begin # handle positional args
+ varname, _varname = _rename(a, x)
+ b.args[i] = :($_varname)
+ push!(varexpr.args, :((if $varname !== nothing
+ $_varname = $varname
+ elseif @isdefined $x
+ # Allow users to define a var in `structural_parameters` and set
+ # that as positional arg of subcomponents; it is useful for cases
+ # where it needs to be passed to multiple subcomponents.
+ $_varname = $x
+ end)))
+ push!(kwargs, Expr(:kw, varname, nothing))
+ # dict[:kwargs][varname] = nothing
+ end
  Expr(:parameters, x...) => begin
- component_args!(a, arg, varexpr, kwargs)
+
+ component_args!(a, arg, varexpr, kwargs; keywords = true)
  end
  Expr(:kw, x, y) => begin
  varname, _varname = _rename(a, x)