/** Handles shorthand notation for collect and expands to an explicit collect expression. */
  private Expression collectShorthandWithOutArgs(String opname, Expression srcExpr)
      throws SemanticException {
    Expression res = null;
    // c.op    200 (5) with implicit (2,4,1)
    CollectionType cType = (CollectionType) srcExpr.type();
    Type elemType = cType.elemType();
    if (elemType.isObjectType()) {
      MClass srcClass = ((ObjectType) elemType).cls();
      MAttribute attr = srcClass.attribute(opname, true);
      if (attr != null) {
        // (2) attribute operation on object type (no arguments)

        // transform c.a into c->collect($e | $e.a)
        ExpVariable eVar = new ExpVariable("$e", elemType);
        ExpAttrOp eAttr = new ExpAttrOp(attr, eVar);
        res = genImplicitCollect(srcExpr, eAttr, elemType);
      } else {
        MAssociationEnd dstEnd = srcClass.navigableEnd(opname);
        if (dstEnd != null) {
          // (4) navigation operation on object type must be
          // a role name

          // transform c.r into c->collect($e | $e.r)
          ExpVariable eVar = new ExpVariable("$e", elemType);
          Expression eNav = genNavigation(fOp, srcClass, eVar, dstEnd);
          res = genImplicitCollect(srcExpr, eNav, elemType);
        }
      }
    }
    if (res == null) {
      // ! objectType || ! (attr ||  navigation)
      // try (1) predefined OCL operation
      res = collectShorthandStdOp(opname, srcExpr, cType, elemType);
    }
    return res;
  }
  private Expression gen1(Context ctx, Expression srcExpr) throws SemanticException {
    Expression res = null;
    String opname = fOp.getText();
    Type srcType = srcExpr.type();

    // generate argument expressions
    fArgExprs = new Expression[fArgs.size() + 1];
    fArgExprs[0] = srcExpr;
    Iterator it = fArgs.iterator();
    int i = 1;
    while (it.hasNext()) {
      ASTExpression astExpr = (ASTExpression) it.next();
      fArgExprs[i++] = astExpr.gen(ctx);
    }

    // flags for various cases
    final int SRC_SIMPLE_TYPE = 0x100;
    final int SRC_OBJECT_TYPE = 0x200;
    final int SRC_COLLECTION_TYPE = 0x400;

    final int DOT = 0x010;
    final int ARROW = 0x020;

    final int NO_PARENTHESES = 0x000;
    final int PARENTHESES = 0x001;

    int opcase;
    if (srcType.isObjectType()) opcase = SRC_OBJECT_TYPE;
    else if (srcType.isCollection()) opcase = SRC_COLLECTION_TYPE;
    else opcase = SRC_SIMPLE_TYPE;

    opcase += fFollowsArrow ? ARROW : DOT;
    opcase += fHasParentheses ? PARENTHESES : NO_PARENTHESES;

    switch (opcase) {
      case SRC_SIMPLE_TYPE + DOT + NO_PARENTHESES:
      case SRC_SIMPLE_TYPE + DOT + PARENTHESES:
      case SRC_COLLECTION_TYPE + ARROW + PARENTHESES:
      case SRC_COLLECTION_TYPE + ARROW + NO_PARENTHESES:
        // (1) predefined OCL operation
        res = genStdOperation(ctx, fOp, opname, fArgExprs);
        break;

      case SRC_SIMPLE_TYPE + ARROW + NO_PARENTHESES:
      case SRC_SIMPLE_TYPE + ARROW + PARENTHESES:
        ctx.reportWarning(
            fOp,
            "application of `"
                + opname
                + "' to a single value should be done with `.' "
                + "instead of `->'.");
        // (1) predefined OCL operation
        res = genStdOperation(ctx, fOp, opname, fArgExprs);
        break;

      case SRC_OBJECT_TYPE + DOT + NO_PARENTHESES:
        MClass srcClass = ((ObjectType) srcType).cls();
        MAttribute attr = srcClass.attribute(opname, true);
        if (attr != null) {
          // (2) attribute operation on object type (no arguments)
          res = new ExpAttrOp(attr, srcExpr);
        } else {
          // (4) navigation operation on object type
          // must be a role name
          MAssociationEnd dstEnd = srcClass.navigableEnd(opname);
          if (dstEnd != null) res = genNavigation(fOp, srcClass, srcExpr, dstEnd);
          else {
            // (1) predefined OCL operation
            res = genStdOperation(ctx, fOp, opname, fArgExprs);
          }
        }
        break;

      case SRC_OBJECT_TYPE + DOT + PARENTHESES:
        // (3) "isQuery" operation on object type (possibly with
        // arguments) or (1)
        MClass srcClass2 = ((ObjectType) srcType).cls();
        res = genObjOperation(ctx, srcClass2, srcExpr);
        break;

      case SRC_OBJECT_TYPE + ARROW + NO_PARENTHESES:
      case SRC_OBJECT_TYPE + ARROW + PARENTHESES:
        // (6) set operation on single object resulting from
        // navigation over associations with multiplicity zero
        // or one (p. 7-13 of OMG UML 1.3)
        if (srcExpr instanceof ExpNavigation) {
          // first map object to set with internal operation
          Expression mappedSrcExpr = new ExpObjAsSet(srcExpr);
          // replace receiver in arg list
          fArgExprs[0] = mappedSrcExpr;
          try {
            // lookup collection operation
            res = ExpStdOp.create(opname, fArgExprs);
          } catch (ExpInvalidException ex) {
            throw new SemanticException(fOp, ex);
          }
        } else {
          throw new SemanticException(
              fOp,
              "An arrow operation treating a single object as a "
                  + "set may only be applied, if the object results "
                  + "from a navigation to an association end with "
                  + "multiplicity 0..1.");
        }
        break;

      case SRC_COLLECTION_TYPE + DOT + NO_PARENTHESES:
        // c.op    200 (5) with implicit (2,4,1)
        if (Options.disableCollectShorthand)
          throw new SemanticException(fOp, MSG_DISABLE_COLLECT_SHORTHAND);
        res = collectShorthandWithOutArgs(opname, srcExpr);
        break;

      case SRC_COLLECTION_TYPE + DOT + PARENTHESES:
        // c.op()  201 (5) with implicit (3,1)
        if (Options.disableCollectShorthand)
          throw new SemanticException(fOp, MSG_DISABLE_COLLECT_SHORTHAND);
        res = collectShorthandWithArgs(opname, srcExpr);
        break;

        //  	    throw new SemanticException(fOp,
        //  		"If you want to apply an operation to a collection, please use an `->' instead of a
        // `.'. If you are trying to apply the shorthand notation for `collect' - sorry, this is not
        // yet supported. Please use the explicit notation.");

      default:
        throw new RuntimeException("case " + Integer.toHexString(opcase) + " not handled");
    }

    if (fIsPre) res.setIsPre();
    return res;
  }