NEWS

ABM 0.6.100

getNeighbors(network, agent) exposes the complete stored network neighbourhood without drawing contacts or scheduling events. It validates population membership and returns borrowed agent pointers that expire when neighbours leave the population.

Contact transitions can now select named contact types, allowing a simulation to use multiple contact patterns. Contact rates now belong to Contact objects; passing a contact object or transition-level rate remains supported temporarily with a deprecation warning.
Population and Simulation constructors now accept a list of initial states, with one list element corresponding to each agent.
Population contact registries are maintained incrementally as populations and contacts join or leave the hierarchy, avoiding repeated full population scans. Contact neighborhoods are also used by reference rather than copied.
External-pointer ownership and lifetime handling has been redesigned to make borrowed R callback handles expire safely, retain R-defined contacts for the simulation lifetime, and prevent stale R6 attachment state after detachment.
Destroying or removing populations now unschedules their agents and contact events. Invalid population cycles and ownership operations are rejected, and adding the same contact more than once remains a no-op.
Membership leases are allocated only when an object is borrowed across the R/C++ boundary, reducing overhead for agents used only within C++.
The package now requires C++17.

External pointers now validate their capability tags. Borrowed handles expire safely when their callback, contact membership, or population lifetime ends.
Agent removal now rejects unattached agents and validates population ownership, preserving agent state when removal fails.
Fixed leaks from transition callbacks and removed the cross-language cycle between R-defined contacts and their C++ bridges.
Added regression tests for external-pointer and contact lifecycle safety.

Added event-driven transition logging with inc() and dec() operations, optional filters, and NULL as the default transition logging setting.
Simulation$addLogger() now accepts a state name with an optional output name. Explicit StateLogger registration and newCounter() are deprecated.
Agent state updates merge named domains, and legacy state-change logging now uses pre- and post-change notifications without cloning the full state.
Simulation state variables are updated in place, avoiding unnecessary state notifications for event-driven counter updates.

Fixed configuration-model networks when agents are added or removed after network construction. New edges now use the sampled degree-weighted node, and removals consistently use population-local indexes.
Configuration-model stubs are now paired without replacement. Self-loops, duplicate edges, and the final dangling stub from an odd total are dropped.
Moving an agent now removes it from its former population and transfers its calendar membership correctly.
Simulation and population constructor initializers now receive one-based indexes, and simulation agent ID counters are initialized deterministically.
Resuming through an interval without events now advances the simulation clock to the requested report time.
Gamma waiting times now interpret their second parameter as a scale.
State loggers now return doubles, and counters support numeric states.
Removed the stale Population$removeAgent() R6 method. Agents are removed from their current population with Agent$leave() or leave().

Fixed a bug that prevented the parsingstate transitions such as list(x="a", y="b")->list("x="A", y="b").
Fixed a possible memory leak suggested by valgrind.
Use cached gamma random number generators to reimplement newGammaWaitingTime.

Fixed a bug that caused the simulation to be incorrect after exhausting random numbers in a cache. This is because refilling the cached random numbers did not correctly setting the RNGScope as required by Rcpp.
Fixed a bug that logged the states at wrong simulation time.
Do not schedule a transition event if the event will never happen (event time is infinity)

Fixed a memory leak bug. This resolved the valgrind check error
Changed the internal handling of agent ID, so that agent ID is unique across all populations.
Fixed a bug that caused agent initializers in the constructor of Simulation to fail.
Fixed a bug that prevent the simulation results to be reproducible.

This release have some API changes regarding the Rcpp manipulation functions, such as schedule, setState and addLogger etc. These functions used to return the object itself for action chaining. Now they do not return a value. However, action changing is still possible using the R6 objects.
Fixed the missing ABM-package documentation.
Fixed a minor memory leak problem caused by the StateLogger class.

Remove agent from a population. This allows agent deaths and moving between populations.

initializers for the state of agents in the population

Initial implementation