Complex patterns in sequence are finally handled in Scala codegen

[amir734jj]

For too long, complex sequence expressions were not handled in Scala code gen and we would get

/workspace/amir/aps/examples$ make -B simple-binding.scala
../bin/aps2scala -DCOTo -p .:../base simple-binding
simple-binding.aps:156:Sequence pattern too complicated for now
shesamian@TDC3791211823:/workspace/amir/aps/examples$ 

Example:

  var function lookup(name : String; scope : Scope) : EntityRef begin
    if scope = root_scope then
      result := not_found;
    else
      case scope.entities begin
	match {...,?e:EntityRef if e.entity_name=name,...} begin
	  result := e;
	end;
      else
	result := lookup(name,scope.enclosing);
      end;
    endif;
  end;

Becomes

  val v_lookup = f_lookup _;
  def f_lookup(v_name : T_String, v_scope : T_Scope):T_EntityRef = {

    { val cond = new M__basic_2[ T_Scope](t_Scope).v__op_0(v_scope,
        v_root_scope);
      if (cond) {
        return v_not_found;
      }
      if (!cond) {
        {
          val sequenceMatch2673192656 = new M__basic_14[ T_EntityRef,T_Entities](t_EntityRef,t_Entities).p__op_AC.unapplySeq(v_entities(v_scope)).get._2.collectFirst {
            case v_e if new M__basic_2[ T_String](t_String).v__op_0(v_entity_name(v_e),
              v_name) => {
              return v_e;
              ()
            }
          }
          if (sequenceMatch2673192656.isEmpty) {
            return v_lookup(v_name,
              v_enclosing(v_scope));
          }
        }
      }
    }
    throw Evaluation.UndefinedAttributeException("local lookup");
  }

[boyland]

Why opnly emit for Scala? How difficult is to make this work for C++ too?