fix: check hasname before using getname

src/systems/abstractsystem.jl

@@ -191,10 +191,15 @@ function SymbolicIndexingInterface.is_variable(sys::AbstractSystem, sym)
            hasname(sym) && is_variable(sys, getname(sym))
 end
 
+function _syms_as_symbols(syms)
+    return [hasname(sym) ? getname(sym) : Symbol(sym) for sym in syms]
+end
+
 function SymbolicIndexingInterface.is_variable(sys::AbstractSystem, sym::Symbol)
-    return any(isequal(sym), getname.(variable_symbols(sys))) ||
+    vars = _syms_as_symbols(variable_symbols(sys))
+    return any(isequal(sym), vars) ||
            count('₊', string(sym)) == 1 &&
-           count(isequal(sym), Symbol.(sys.name, :₊, getname.(variable_symbols(sys)))) == 1
+           count(isequal(sym), Symbol.(sys.name, :₊, vars)) == 1
 end
 
 function SymbolicIndexingInterface.variable_index(sys::AbstractSystem, sym)
@@ -209,11 +214,12 @@ function SymbolicIndexingInterface.variable_index(sys::AbstractSystem, sym)
 end
 
 function SymbolicIndexingInterface.variable_index(sys::AbstractSystem, sym::Symbol)
-    idx = findfirst(isequal(sym), getname.(variable_symbols(sys)))
+    vars = _syms_as_symbols(variable_symbols(sys))
+    idx = findfirst(isequal(sym), vars)
     if idx !== nothing
         return idx
     elseif count('₊', string(sym)) == 1
-        return findfirst(isequal(sym), Symbol.(sys.name, :₊, getname.(variable_symbols(sys))))
+        return findfirst(isequal(sym), Symbol.(sys.name, :₊, vars))
     end
     return nothing
 end
@@ -234,9 +240,10 @@ function SymbolicIndexingInterface.is_parameter(sys::AbstractSystem, sym)
 end
 
 function SymbolicIndexingInterface.is_parameter(sys::AbstractSystem, sym::Symbol)
-    return any(isequal(sym), getname.(parameter_symbols(sys))) ||
+    vars = _syms_as_symbols(parameter_symbols(sys))
+    return any(isequal(sym), vars) ||
            count('₊', string(sym)) == 1 &&
-           count(isequal(sym), Symbol.(sys.name, :₊, getname.(parameter_symbols(sys)))) == 1
+           count(isequal(sym), Symbol.(sys.name, :₊, vars)) == 1
 end
 
 function SymbolicIndexingInterface.parameter_index(sys::AbstractSystem, sym)
@@ -251,11 +258,12 @@ function SymbolicIndexingInterface.parameter_index(sys::AbstractSystem, sym)
 end
 
 function SymbolicIndexingInterface.parameter_index(sys::AbstractSystem, sym::Symbol)
-    idx = findfirst(isequal(sym), getname.(parameter_symbols(sys)))
+    vars = _syms_as_symbols(parameter_symbols(sys))
+    idx = findfirst(isequal(sym), vars)
     if idx !== nothing
         return idx
     elseif count('₊', string(sym)) == 1
-        return findfirst(isequal(sym), Symbol.(sys.name, :₊, getname.(parameter_symbols(sys))))
+        return findfirst(isequal(sym), Symbol.(sys.name, :₊, vars))
     end
     return nothing
 end