Class Configuration

Create a transition back to the containing configuration.

This is done when a configuration is in an accepting state and there are candidate transitions to other states that must be considered. The transition does not consume a symbol.

Execute steps to leave a sub-automaton.

Parameters:

• sub_configuration - The configuration associated with the automata that has completed.

Returns:

self

Execute steps to enter a new automaton.

The new automaton is removed from the set of remaining automata for the current state, and a new configuration created. No transition is made in that new configuration.

Parameters:

• automaton - The automaton to be entered

Returns:

The configuration that executes the new automaton as a sub-configuration of self.

Return list of viable transitions on symbol

The transitions that are structurally permitted from this state, in order, filtering out those transitions where the update instruction is not satisfied by the configuration counter values and optionally those for which the symbol does not match.

Parameters:

• symbol - A symbol through which a transition from this state is intended. A value of None indicates that the set of transitions should ignore the symbol; candidates are still filtered based on the counter state of the configuration.

Returns:

A list of Transition instances permitted from the current configuration. If symbol is not None, transitions that would not accept the symbol are excluded. Any transition that would require an unsatisfied counter update is also excluded. Non-deterministic automata may result in a lits with multiple members.

Return the acceptable Symbols given the current configuration.

This method extracts the symbol from all candidate transitions that are permitted based on the current counter values. Because transitions are presented in a preferred order, the symbols are as well.

Overrides: Configuration_ABC.acceptableSymbols

(inherited documentation)

Execute an automaton transition using the given symbol.

Parameters:

• symbol - A symbol from the alphabet of the automaton's language. This is a Python value that should be accepted by the SymbolMatch_mixin.match method of a State.symbol. It is not a Symbol instance.

Returns:

The new configuration resulting from the step.

Raises:

• AutomatonStepError - UnrecognizedSymbolError when no transition compatible with symbol is available, and NondeterministicSymbolError if symbol admits multiple transitions and the subclass does not support non-deterministic steps (see MultiConfiguration).

Overrides: Configuration_ABC.step

(inherited documentation)

x.__init__(...) initializes x; see help(type(x)) for signature

Overrides: object.__init__

(inherited documentation)

Clone a configuration and its descendents.

This is used for parallel execution where a configuration has multiple candidate transitions and must follow all of them. It clones the entire chain of configurations through multiple layers.

Parameters:

• clone_map - Optional map into which the translation from the original configuration object to the corresponding cloned configuration object can be reconstructed, e.g. when applying a transition that includes automata exits referencing superconfigurations from the original configuration.

str(x)

Overrides: object.__str__

(inherited documentation)

state

The state of the configuration.

This is None to indicate an initial state, or one of the underlying automaton's states.

Get Method:

__get_state(self) - The state of the configuration.

automaton

Get Method:

__get_automaton(self)

subConfiguration

Reference to configuration being executed in a sub-automaton.

None if no sub-automaton is active, else a reference to a configuration that is being executed in a sub-automaton.

Sub-configurations are used to match sub-terms in an unordered catenation term. A configuration may have at most one sub-configuration at a time, and the configuration will be removed and possibly replaced when the term being processed completes.

Get Method:

__get_subConfiguration(self) - Reference to configuration being executed in a sub-automaton.

superConfiguration

Reference to the configuration for which this is a sub-configuration.

None if no super-automaton is active, else a reference to a configuration that is being executed in a super-automaton.

The super-configuration relation persists for the lifetime of the configuration.

Get Method:

__get_superConfiguration(self) - Reference to the configuration for which this is a sub-configuration.

subAutomata

A set of automata that must be satisfied before the current state can complete.

This is used in unordered catenation. Each sub-automaton represents a term in the catenation. When the configuration enters a state with sub-automata, a set containing references to those automata is assigned to this attribute. Subsequently, until all automata in the state are satisfied, transitions can only occur within an active sub-automaton, out of the active sub-automaton if it is in an accepting state, and into a new sub-automaton if no sub-automaton is active.

Get Method:

__get_subAutomata(self) - A set of automata that must be satisfied before the current state can complete.