Crate rustsim_core 

Core ABM engine for rustsim.

This crate provides the foundational abstractions for agent-based modelling:

• Agent trait - the interface every agent type must implement.
• Model trait - the abstract model interface exposing time, RNG, space, and agents.
• StandardModel - discrete-time model with per-agent and per-model step functions.
• EventQueueModel - continuous-time model driven by a deterministic event queue.
• AgentStore - container trait with HashMapStore and VecStore implementations.
• Scheduler - trait for controlling agent activation order each step.
• StepContext - safe, borrow-checked context passed to agent step functions.
• Core semantic types - shared identifiers and interfaces for nodes, edges, zones, levels, and connectors.
• SoaExtractable - trait for extracting agent data into GPU-friendly SoA buffers.

Architecture

The crate mirrors the design of Julia’s Agents.jl:

1. Define agent types implementing Agent.
2. Choose a space (from rustsim-spaces) and a scheduler.
3. Wire up step functions and build a StandardModel or EventQueueModel.
4. Call StandardModel::step / StandardModel::step_n to advance the simulation.
5. Use collect_step to gather data at each step.

Interior Mutability

Agent stores use RefCell-based interior mutability so that agent step functions can read other agents while mutating the current one. This means the model types are !Send and !Sync - see the top-level rustsim crate for compute-routing alternatives.

Modules

agent

Agent trait - the fundamental interface for all simulation entities.

avoidance

Physical avoidance force primitives for pedestrian and agent dynamics.

collect

Data collection utilities.

event_queue

Continuous-time event-queue model.

interaction

Space interaction API - add, remove, move, and query agents in space.

messaging

Inter-agent messaging system inspired by FlameGPU2.

model

Abstract model trait - the interface shared by all model types.

prelude

scheduler

Scheduler trait and built-in implementations.

soa

SoA (Structure-of-Arrays) extraction for GPU-friendly data layout.

space

Space trait - marker for spatial structures in which agents exist.

standard

Discrete-time standard model.

step_context

Deferred actions and the step context passed to agent step functions.

store

Agent containers - storage backends for the agent population.

two_phase

Two-phase stepping utilities inspired by FlameGPU2.

types

Fundamental identity, semantic, and time types used throughout the ABM engine.