Package pyxb :: Package utils :: Module fac :: Class Transition |
[hide private]
[frames] | no frames]

# type Transition

source code

    object --+
             |
            Transition

Representation of a FAC state transition.

Instance Methods | [hide private]
__get_destination(self) The transition destination state. | source code
__get_updateInstructions(self) The set of counter updates that are applied when the transition is taken. | source code
__get_nextTransition(self) The next transition to apply in this chain. | source code
__get_layerLink(self) A directive relating to changing automaton layer on transition. | source code
__init__(self, destination, update_instructions, layer_link=None) Create a transition to a state. | source code
consumingState(self) Return the state in this transition chain that must match a symbol. | source code
consumedSymbol(self) Return the symbol of the consumingState. | source code
satisfiedBy(self, configuration) Check the transition update instructions against configuration counter values. | source code
apply(self, configuration, clone_map=None) Apply the transitition to a configuration. | source code
chainTo(self, next_transition) Duplicate the state and chain the duplicate to a successor transition. | source code
makeEnterAutomatonTransition(self) Replicate the transition as a layer link into its automaton. | source code
__hash__(self) | source code
__eq__(self, other) | source code
__ne__(self, other) | source code
__str__(self) | source code

Class Variables | [hide private]
| __destination = `None`
| __updateInstructions = `None`
| __nextTransition = `None`
| __layerLink = `None`

Properties | [hide private]
| destination The transition destination state.
| updateInstructions The set of counter updates that are applied when the transition is taken.
| nextTransition The next transition to apply in this chain.
| layerLink A directive relating to changing automaton layer on transition.

Method Details | [hide private]

### __get_nextTransition(self) | source code
The next transition to apply in this chain. `None` if this is the last transition in the chain.

### __get_layerLink(self) | source code
A directive relating to changing automaton layer on transition. `None` indicates this transition is from one state to another within a single automaton. An instance of Configuration is a transition on completion of a subautomaton back to the configuration in the parent automaton. The destination is the state in the parent automaton. An instance of Automaton requires creation of a sub-configuration and initial entry into the automaton. The destination is the state in the sub-automaton.

### __init__(self, destination, update_instructions, layer_link=None) (Constructor) | source code
Create a transition to a state. Parameters: `destination` - the state into which the transition is made `update_instructions` - A iterable of UpdateInstructions denoting the changes that must be made to counters as a consequence of taking the transition. `layer_link` - The value for layerLink. Overrides: object.__init__

### satisfiedBy(self, configuration) | source code
Check the transition update instructions against configuration counter values. This implementation follows layer changes, updating the configuration used as counter value source as necessary. Parameters: `configuration` - A Configuration instance containing counter data against which update instruction satisfaction is checked. Returns: `True` iff all update instructions along the transition chain are satisfied by their relevant configuration.

### apply(self, configuration, clone_map=None) | source code
Apply the transitition to a configuration. This updates the configuration counter values based on the update instructions, and sets the new configuration state. Parameters: `configuration` - A Configuration of an executing automaton `clone_map` - A map from Configuration to Configuration reflecting the replacements made when the configuration for which the transition was calculated was subsequently cloned into the `configuration` passed into this method. This is only necessary when the transition includes layer transitions. Returns: The resulting configuration Note: If the transition involves leaving a sub-automaton or creating a new sub-automaton, the returned configuration structure will be different from the one passed in. You should invoke this as:
     cfg = transition.apply(cfg)

### chainTo(self, next_transition) | source code
Duplicate the state and chain the duplicate to a successor transition. This returns a new transition which applies the operation for this transition, then proceeds to apply the next transition in the chain. Parameters: `next_transition` - A Transition node describing a subsequent transition. Returns: a clone of this node, augmented with a link to `next_transition`. Note: The node that is invoking this must not have successor transitions.

### makeEnterAutomatonTransition(self) | source code
Replicate the transition as a layer link into its automaton. This is used on initial transitions into sub-automata where a sub-configuration must be created and recorded.

### __hash__(self) (Hashing function) | source code
Overrides: object.__hash__ (inherited documentation)

### __str__(self) (Informal representation operator) | source code
Overrides: object.__str__ (inherited documentation)

Property Details | [hide private]

### destination The transition destination state. Get Method: __get_destination(self) - The transition destination state.

### updateInstructions The set of counter updates that are applied when the transition is taken. Get Method: __get_updateInstructions(self) - The set of counter updates that are applied when the transition is taken.

### nextTransition The next transition to apply in this chain. `None` if this is the last transition in the chain. Get Method: __get_nextTransition(self) - The next transition to apply in this chain.

### layerLink A directive relating to changing automaton layer on transition. `None` indicates this transition is from one state to another within a single automaton. An instance of Configuration is a transition on completion of a subautomaton back to the configuration in the parent automaton. The destination is the state in the parent automaton. An instance of Automaton requires creation of a sub-configuration and initial entry into the automaton. The destination is the state in the sub-automaton. Get Method: __get_layerLink(self) - A directive relating to changing automaton layer on transition.