feat: adds @structural_parameters to @mtkmodel

- This will allow to provide arguments that aren't parameters/variables like int, function...
- Adds tests for the same

Author: ven-k

src/systems/model_parsing.jl

@@ -22,15 +22,13 @@ function _model_macro(mod, name, expr, isconnector)
     ext = Ref{Any}(nothing)
     eqs = Expr[]
     icon = Ref{Union{String, URI}}()
-    vs = []
-    ps = []
-    kwargs = []
+    kwargs, ps, sps, vs, = [], [], [], []
 
     for arg in expr.args
         arg isa LineNumberNode && continue
         if arg.head == :macrocall
             parse_model!(exprs.args, comps, ext, eqs, icon, vs, ps,
-                dict, mod, arg, kwargs)
+                sps, dict, mod, arg, kwargs)
         elseif arg.head == :block
             push!(exprs.args, arg)
         elseif isconnector
@@ -213,8 +211,8 @@ function get_var(mod::Module, b)
     end
 end
 
-function parse_model!(exprs, comps, ext, eqs, icon, vs, ps, dict,
-    mod, arg, kwargs)
+function parse_model!(exprs, comps, ext, eqs, icon, vs, ps, sps,
+    dict, mod, arg, kwargs)
     mname = arg.args[1]
     body = arg.args[end]
     if mname == Symbol("@components")
@@ -225,6 +223,8 @@ function parse_model!(exprs, comps, ext, eqs, icon, vs, ps, dict,
         parse_variables!(exprs, vs, dict, mod, body, :variables, kwargs)
     elseif mname == Symbol("@parameters")
         parse_variables!(exprs, ps, dict, mod, body, :parameters, kwargs)
+    elseif mname == Symbol("@structural_parameters")
+        parse_structural_parameters!(exprs, sps, dict, mod, body, kwargs)
     elseif mname == Symbol("@equations")
         parse_equations!(exprs, eqs, dict, body)
     elseif mname == Symbol("@icon")
@@ -234,6 +234,24 @@ function parse_model!(exprs, comps, ext, eqs, icon, vs, ps, dict,
     end
 end
 
+function parse_structural_parameters!(exprs, sps, dict, mod, body, kwargs)
+    Base.remove_linenums!(body)
+    for arg in body.args
+        MLStyle.@match arg begin
+            Expr(:(=), a, b) => begin
+                push!(sps, a)
+                push!(kwargs, Expr(:kw, a, b))
+                dict[:kwargs][a] = b
+            end
+            a => begin
+                push!(sps, a)
+                push!(kwargs, a)
+                dict[:kwargs][a] = nothing
+            end
+        end
+    end
+end
+
 function parse_components!(exprs, cs, dict, body, kwargs)
     expr = Expr(:block)
     varexpr = Expr(:block)

test/model_parsing.jl

@@ -121,15 +121,16 @@ end
 end
 
 @mtkmodel RC begin
-    @parameters begin
+    @structural_parameters begin
         R_val = 10
-        C_val = 5
+        C_val = 10
+        k_val = 10
     end
     @components begin
         resistor = Resistor(; R = R_val)
         capacitor = Capacitor(; C = C_val)
         source = Voltage()
-        constant = Constant(; k = 1)
+        constant = Constant(; k = k_val)
         ground = Ground()
     end
 
@@ -141,12 +142,17 @@ end
     end
 end
 
-@named rc = RC(; R_val = 20)
-params = ModelingToolkit.get_ps(rc)
-@test isequal(getdefault(rc.resistor.R), params[1])
-@test isequal(getdefault(rc.capacitor.C), params[2])
+C_val = 20
+R_val = 20
+res__R = 100
+@named rc = RC(; C_val, R_val, resistor.R = res__R)
+# Test that `resistor.R` overrides `R_val` in the argument.
+@test getdefault(rc.resistor.R) == res__R != R_val
+# Test that `C_val` passed via argument is set as default of C.
+@test getdefault(rc.capacitor.C) == C_val
+# Test that `k`'s default value is unchanged.
+@test getdefault(rc.constant.k) == RC.structure[:kwargs][:k_val]
 @test getdefault(rc.capacitor.v) == 0.0
-@test getdefault(rc.constant.k) == 1
 
 @test get_gui_metadata(rc.resistor).layout == Resistor.structure[:icon] ==
       read(joinpath(ENV["MTK_ICONS_DIR"], "resistor.svg"), String)
@@ -177,10 +183,14 @@ params = ModelingToolkit.get_ps(rc)
         j(t) = jval, [description = "j(t)"]
         k = kval, [description = "k"]
     end
+    @structural_parameters begin
+        l = 1
+        func
+    end
 end
 
 kval = 5
-@named model = MockModel(; kval, cval = 1)
+@named model = MockModel(; kval, cval = 1, func = identity)
 
 @test hasmetadata(model.e, VariableDescription)
 @test hasmetadata(model.f, VariableDescription)