Because there is a conflict between the way in which DDS handles default union initialization and the way the IDL4 spec describes it, we need to clarify the exact behavior at the individual language mappings. This has already been done in the current proposal for the IDL4-Python language mapping, but should similarly be done for the other languages.

The bitmask mapping lacks the operator&, operator|, operator^, operator~, see https://en.cppreference.com/w/cpp/named_req/BitmaskType, a bitmask type in C++ should have these

C++20 modules look very interesting for sharing declarations/definitions based on IDL (see https://en.cppreference.com/w/cpp/language/modules), would be good when this spec has support for C++20 modules

ptc/19-07-02 section 7.2.4.2.1 defines the mapping of sequences of basic and non basic types in terms of Java interfaces.
However, the classes implementing the interfaces are not defined.
The implementation classes are required for actual programming.
If it is intended that the user shall provide own implementations then this should be expressly stated.

7.3 Any says:

"The IDL any type shall be mapped to org.omg.type.Any type."

A.1.4 Any says:

"The IDL type any maps to a public class named org.omg.CORBA.Any with the following definition

package org.omg.CORBA;
public class Any {
..."

Suggested solution:

Replace class declaration with:

"package org.omg.CORBA;
public class Any implements org.omg.type.Any {
..."

IDL 4.2 section 7.4.1.4.3 Constants consistency rules on page 32 contains

• An octet constant can be defined using an integer literal or an integer constant expression but values outside the range 0…255 shall be treated as an error.

ptc/20-05-17 section 7.2.4.1.6 maps IDL octet to Java byte.
For mapping IDL const octet values 128 to 255 to Java, it should be permissible to apply promote_integer_width to octet.

This building block section is missing (e.g. sbyte).

It seems every section has this deviation of alternative identifier mappings. I find that it maps the document more difficult to read. The document at large should provide canonical text and examples. These alternatives should be placed in a section that caters to those alternatives with easy links to this section elsewhere in the document.

I could not find a place that discussed what is expected if an IDL compiler encounters an annotation that it can parse but does not understand.

The section on annotations should contain examples of how to use the various standard annotations.

This section needs to be filled out with examples of anonymous IDL types.

The example uses annotation to define the type. The mapping should be clean/pure without annotations. The annotation should be moved to the sections on annotations.
// IDL
enum AnEnum

;

// Java
public enum AnEnum {
X,
Y;
private int value;
private AnEnum(int value)

public int getValue()

public static AnEnum valueOf(int v)

7.17 Standardized Annotations
}

Same as the description

Ensure the correct separation of building block basic types (e.g. sbye)

There needs to be a section on IDL interfaces being mapped to Java 8 interfaces which provide the capability to be a proper container. This removes the need for the old fooPackage id foo were defined in an IDL interface named foo.

How are bitsets that use inheritance mapped?

Something I noticed while looking at the union mapping for CORBA. Why is it that the IDL4 mapping uses two underscores prepended to the default method (e.g. __default v.s. _default)?

If there is no technical reason for it I think the single underscore is preferred.

The ptc/19-07-02 section 7.2.4.4 proposes a weak mapping for IDL arrays in that they are mapped directly to Java arrays.
This means that the fixed size nature of IDL arrays cannot be enforced at the location of usage (e.g. index checking and handling of variable size operations of java.util.List).

On the other hand, 7.2.4.2.1.1 does define an abstraction for "Sequence of Basic Types", see Table 7.4 where e.g. sequence<boolean> is mapped to the interface BooleanSeq.
A similar mapping could be defined for IDL arrays.

Example:

  // IDL
  enum Color { RED, GREEN, BLUE };

  typedef Color ColorArray[3];

could be mapped to

  public enum Color {
    // [...]
  }

  public class ColorArray implements org.omg.type.Array<Color> {
    public ColorArray() {
      elementData = new Color[3];   // initialize private member
    }
    // [...] most of the operations can be implemented in the superclass
  }

The generic abstract class org.omg.type.Array would provide getter, setter, and other methods. It could also throw an exception on use of java.util.List operations that undermine the fixed size. I can provide a demo implementation of the class if desired.

If it is desired to maintain the possibility of using plain Java arrays then the mapping could be made switchable via an annotation.

Examples given throughout ptc/19-07-02 make indiscriminate use of anonymous types; see

• 7.2.4.2.1.2 struct MyType
• 7.2.4.4 struct S2
• 7.2.4.6 struct MyType
• 7.14.3.1 struct S4

For IDL compatibility with other mappings that do not support anonymous types (see e.g. C++11 mapping version 1.4 stion 6.2), the examples should preferably use typedefs.
Further, it should be mentioned that anonymous types can incur portability problems when used with other language mappings.

Interfaces - Full should define a FooOperations interface like we have done in the IDL to C# Language Mapping.

Also, public abstract void op1(S sIn); should be changed to void op1(S sIn);.

The revised submission contains a number of typos and inconsistencies that should be fixed:

• In Clause 7.2.4.2.1.1, Sequence of Basic Types, IntarfaceName should be InterfaceName.

• In Clause 7.2.4.2.1.2, Sequence of non Basic Types, the text describing when to throw an exception is somewhat repetitive.

• In Clause 7.2.4.3.2 Unions, the requirement for implementing java.io.Serializable is repeated.

In section 7.2.4.2.1.1 on page 13 top of page after end of fixed font Java code:

Where:
• <IntarfaceName> is the interface name indicated in Table 7.4.

<IntarfaceName> should be <InterfaceName>

In Clause 7.2.4.2.1.2, Sequence of non Basic Types, the text describing when to throw an exception is somewhat repetitive.

In Clause 7.2.4.3.2 Unions, the requirement for implementing java.io.Serializable is repeated.

In section 7.2.4.3.2 on page 16 paragraph before the union U1 example:

[...] The first modifier method shall
take no arguments, return void, and setsthe discriminant to the first available default value starting from a 0 index of the
discriminant type.

setsthe should be set the.

In section 8.1.3 table 8.2 column "IDL Construct", repeated typo:
Accesor should be Accessor.
In particular, on page 32:

Structure Member Name in
Accesor/Modifier Methods

Union Member Name in
Accesor/Modifier Methods

and on page 33:

Interface Attribute Name in
Accesor/Modifier Methods

Exception Member Name in
Accesor/Modifier Methods

Bitfield Name in Bitset
Accesor/Modifier Methods

Throughout the document URIs starting with "http://" should start with "https://" instead.