An Alf-Text can be transformed into an Element of a model (e.g. an Activity). Both representations are equivalent. Nonetheless it makes sense, to store both representations, since both might have user defined formating, that we want to preserve. The specification defines a means for this:

[the original Alf text is stored] by attaching a comment to the top-level element resulting from the processing of an Alf model unit with the Alf text for the unit as the body.

This asks for the Alf model unit, which is not included on full conformance level:

Full Conformance. Conformance at this level requires the ability to process all the syntax defined in Clauses 8 and 9, but none of the syntax defined in Clause 10 [Units].

suggested addition

A tool supporting only full conformance level (that doesn't include units) may show the behavioral constructs only.

problem
This means there will be two ways how a Textual Representation will show up in the xmi-file. This may cause problems for the interoperability. Maybe we can define, that however the tool displays a Textual Representation, the serialization should always include the full Alf Unit.

Hi,

there is this really minor bug, that on page 308 is some text "This page is intentionally left blank" in the background.

Best,
Christian

Annex A.3 Composite Structure discusses (non-normatively) the use of Alf with UML composite structure models. This should be updated, now that the Precise Semantics of UML Composite Structures (PSCS) specification has been adopted, providing a formal fUML-based semantics for composite structures.

Several of the operations in the collection classes require that two general objects can be compared for equality (one example is Collection::includes).
The standard should clarify how the equality comparison is done. Will the equality operator == always be used, or is it possible for the user to define the condition for how to compare objects of a user-defined class?
If the equality operator == is used for all objects, this will limit the usefulness of the collection library. For some kinds of objects a comparison based on object identity is not appropriate.
We propose that object identity comparisons is only the default for class objects, and that it can be customized by defining an equals operation in the class.

Why not include Model to Text for generating ALF for (a subset of) UML?

It would be very good if the ALF standard could support a syntax for defining local names with "composite semantics". That is, names for which the value will be automatically destroyed when leaving the current scope. As it is now, objects for local names need to be created explicitly with 'new' and then destroyed explicitly by calling a destructor on the object. It is a very common pattern that objects only should live while inside a particular scope, and then it is error-prone to have to destroy all such objects manually.
Note that the proposed syntax must be within the minimum conformance subset of the language. Our proposal is to use a syntax similar to the following:

auto<MyClass> var = new MyClass();

When we read chapter 9.12 we conclude that the traditional for-statement of languages such as C/C++ and Java, is not supported by Alf. Only for-statements that iterate based on collections are supported now.
We think the traditional for-statement with loop variable initialization, termination condition and iteration step should be supported. For example
for (Integer i = 0; i < x; i++)

We are missing an Alf statement corresponding to the UML RaiseExceptionAction. Such a statement is needed in order to raise exceptions from Alf code. The syntax should be within the minimum conformance subset ("throw").

There should be an Alf statement that allows to define an exception handler for a block. The syntax should be within the minimum conformance subset (try - catch).