causality/DGPetri¶

class mod.DGPetriNet¶

Adaptation of a derivation graph into a Petri net. Importantly, if the underlying derivation graph is enlarged then syncSize() must be called before calling certain other methods on the object.

__init__(dg)¶

Calls syncSize().

Parameters:: dg (DG) – the derivation graph to adapt.
Returns:: a new Petri net, adapting the given derivation graph.
Raises:: LogicError if dg is None.
Raises:: LogicError if neither dg.hasActiveBuilder nor dg.locked.

dg¶

(Read-only) The underlying derivation graph.

Type:: DG

syncSize()¶: Enlarges the internal data structures to the current size of the underlying derivation graph.

getPostPlaces(e)¶

Parameters:: e (DGHyperEdge) – the hyperedge to find unique targets for.
Returns:: a list of unique targets for the given hyperedge.
Return type:: list[DGVertex]

Requires syncSize() to have been called since the last time the underlying derivation graph has changed size.

class mod.DGPetriNetMarking¶

Representation of a marking on a Petri net. Importantly, if the underlying derivation graph is enlarged then syncSize() must be called before calling certain other methods on the object.

__init__(net)¶

Parameters:: net (DGPetriNet) – the Petri net to construct a marking for.
Raises:: LogicError if net is None.

net¶

(Read-only) The underlying Petri net.

Type:: DGPetriNet

syncSize()¶

Enlarges the internal data structures to the current size of the underlying derivation graph.

Calls net.syncSize().

__eq__()¶

add(v, c)¶

Add c tokens on the place v.

Parameters:

v (DGVertex) – the place to add tokens to.
c (int) – the amount of tokens to add.

Returns:

the new total token count on v.

Return type:

int

Raises:

LogicError if not v.

Raises:

LogicError if v.dg != self.net.dg.

Throws:

LogicError if c < 0.

Requires syncSize() to have been called since the last time the underlying derivation graph has changed size.

remove(v, c)¶

Remove c tokens from the place v.

Parameters:

v (DGVertex) – the place to remove tokens from.
c (int) – the amount of tokens to remove.

Returns:

the new total token count on v.

Return type:

int

Raises:

LogicError if not v.

Raises:

LogicError if v.dg != self.net.dg.

Throws:

LogicError if c < 0.

Throws:

LogicError if not enough tokens are left to remove all c.

Requires syncSize() to have been called since the last time the underlying derivation graph has changed size.

__getitem__(v)¶

Parameters:: v (DGVertex) – the place to remove tokens from.
Returns:: the token count for v.
Return type:: int
Raises:: LogicError if not v.
Raises:: LogicError if v.dg != self.net.dg.

Requires syncSize() to have been called since the last time the underlying derivation graph has changed size.

numTokens¶

(Read-only) The total number of tokens in the marking.

Type:: int

getAllEnabled()¶

Returns:: a list of all hyperedges currently enabled for firing.
Return type:: list[DGHyperEdge]

getNonZeroPlaces()¶

Returns:: a list of all vertices with tokens.
Return type:: list[DGVertex]

getEmptyPostPlaces(e)¶

Parameters:: e (DGHyperEdge) – the edge to query for empty post places.
Returns:: a list of all target vertices of the given hyperedge that do not have any tokens. The list represents a set, so if vertex is a target multiple times it will only be included once.
Return type:: list[DGVertex]
Raises:: LogicError if not e.
Raises:: LogicError if e.dg != self.net.dg.

isEnabled(e)¶

Parameters:: e (DGHyperEdge) – the edge to query for being enabled.
Returns:: whether the given hyperedge is enabled for firing.
Return type:: bool
Raises:: LogicError if not e.
Raises:: LogicError if e.dg != self.net.dg.

fire(e)¶

Parameters:: e (DGHyperEdge) – the edge to fire.
Raises:: LogicError if not e.
Raises:: LogicError if e.dg != self.net.dg.
Raises:: LogicError if not self.isEnabled(e).