Combined fragment dialog box

Combined fragments

A combined fragment is used to group several messages into structured blocks.

A combined fragment is made up of one or more interaction operands that structure the messages.

The "Combined fragment" dialog box contains four tabs - "Properties", "Notes", "Tagged values" and "Stereotypes". For information on these standard dialog box tabs, please see "Standard dialog box tabs".

The "Properties" tab of the "Combined fragment" dialog box

The "Properties" tab of the "Combined fragment" dialog box is used to define values for a combined fragment.

The "Properties" tab of the "Combined fragment" dialog box

Key:

· "Name": This is the name of the combined fragment.

· "Operator": This is the operator which precisely defines the semantics of the combined fragment. The semantics of a combined fragment are dependent upon this interaction operator. Possible operators are as follows:

o alt: the combined fragment represents a choice of behavior. At most, one of the operands will be chosen.

o opt : the combined fragment represents a choice of behavior where either the (sole) operand happens or nothing happens.

o par:  the combined fragment means that the interaction operands execute in parallel.

o loop:  the combined fragment represents a loop. The loop operand will be repeated a number of times.

o critical: the combined fragment represents a critical region.

o neg:  the combined fragment represents traces that are defined to be invalid.

o break:  the combined fragment represents a breaking scenario in the sense that the operand is a scenario that is performed instead of the remainder of the enclosing interaction fragment. A break operator with a guard is chosen when the guard is true and the rest of the enclosing interaction fragment is ignored.

o seq:  the combined fragment represents a weak sequencing between the behaviors of the operands.

o strict: the combined fragment represents a strict sequencing between the behaviors of the operands.

o assert:  the combined fragment represents an assertion. The sequences of the operand of the assertion are the only valid continuations. All other continuations result in an invalid trace. 

o ignore: designates that there are some message types that are not shown within this combined fragment. These message types can be considered insignificant and are implicitly ignored if they appear in a corresponding execution.

o consider: designates which messages should be considered within this combined fragment. This is equivalent to defining every other message to be ignored.