Issue with enumeration-indexed arrays in NF

[Francesco Casella]

Please consider the model ​Modelica.Electrical.Digital.Examples.FlipFlop. The following runtime error is reported by the NF:

assert            | error   | Dimension 1 has bounds 1..9, got array subscript 0
assert            | info    | simulation terminated by an assertion at initialization

In the old FE, equations such as this one were flattened:

  FF.RS2.Nor2.auxiliary_n = {Modelica.Electrical.Digital.Interfaces.Logic.'U', Modelica.Electrical.Digital.Interfaces.Logic.'X', Modelica.Electrical.Digital.Interfaces.Logic.'1', Modelica.Electrical.Digital.Interfaces.Logic.'0', Modelica.Electrical.Digital.Interfaces.Logic.'X', Modelica.Electrical.Digital.Interfaces.Logic.'X', Modelica.Electrical.Digital.Interfaces.Logic.'1', Modelica.Electrical.Digital.Interfaces.Logic.'0', Modelica.Electrical.Digital.Interfaces.Logic.'X'}[FF.RS2.Nor2.auxiliary[2]];

In the NF, this is obtained instead:

  FF.RS2.Nor2.auxiliary_n = Modelica.Electrical.Digital.Tables.NotTable[FF.RS2.Nor2.auxiliary[2]];

  constant enumeration('U', 'X', '0', '1', 'Z', 'W', 'L', 'H', '-') Modelica.Electrical.Digital.Tables.NotTable[Modelica.Electrical.Digital.Interfaces.Logic.'U'] = Modelica.Electrical.Digital.Interfaces.Logic.'U' "9-value logic for 'not'";
  constant enumeration('U', 'X', '0', '1', 'Z', 'W', 'L', 'H', '-') Modelica.Electrical.Digital.Tables.NotTable[Modelica.Electrical.Digital.Interfaces.Logic.'X'] = Modelica.Electrical.Digital.Interfaces.Logic.'X' "9-value logic for 'not'";
  constant enumeration('U', 'X', '0', '1', 'Z', 'W', 'L', 'H', '-') Modelica.Electrical.Digital.Tables.NotTable[Modelica.Electrical.Digital.Interfaces.Logic.'0'] = Modelica.Electrical.Digital.Interfaces.Logic.'1' "9-value logic for 'not'";
  constant enumeration('U', 'X', '0', '1', 'Z', 'W', 'L', 'H', '-') Modelica.Electrical.Digital.Tables.NotTable[Modelica.Electrical.Digital.Interfaces.Logic.'1'] = Modelica.Electrical.Digital.Interfaces.Logic.'0' "9-value logic for 'not'";
  constant enumeration('U', 'X', '0', '1', 'Z', 'W', 'L', 'H', '-') Modelica.Electrical.Digital.Tables.NotTable[Modelica.Electrical.Digital.Interfaces.Logic.'Z'] = Modelica.Electrical.Digital.Interfaces.Logic.'X' "9-value logic for 'not'";
  constant enumeration('U', 'X', '0', '1', 'Z', 'W', 'L', 'H', '-') Modelica.Electrical.Digital.Tables.NotTable[Modelica.Electrical.Digital.Interfaces.Logic.'W'] = Modelica.Electrical.Digital.Interfaces.Logic.'X' "9-value logic for 'not'";
  constant enumeration('U', 'X', '0', '1', 'Z', 'W', 'L', 'H', '-') Modelica.Electrical.Digital.Tables.NotTable[Modelica.Electrical.Digital.Interfaces.Logic.'L'] = Modelica.Electrical.Digital.Interfaces.Logic.'1' "9-value logic for 'not'";
  constant enumeration('U', 'X', '0', '1', 'Z', 'W', 'L', 'H', '-') Modelica.Electrical.Digital.Tables.NotTable[Modelica.Electrical.Digital.Interfaces.Logic.'H'] = Modelica.Electrical.Digital.Interfaces.Logic.'0' "9-value logic for 'not'";
  constant enumeration('U', 'X', '0', '1', 'Z', 'W', 'L', 'H', '-') Modelica.Electrical.Digital.Tables.NotTable[Modelica.Electrical.Digital.Interfaces.Logic.'-'] = Modelica.Electrical.Digital.Interfaces.Logic.'X' "9-value logic for 'not'";

I'm not sure how this is actually rendered in terms of internal data structures, but it seems that the new one is not accepted by the subsequent code generation phases.