1.0pre4

CHANGELOG.md

@@ -13,11 +13,13 @@ For an explanation of the general changes in version 1.0, please refer to the fi
 * Environments now have a class method to make them easier to use without a simulation`.run`. Notice that this is different from `run_model`, which is an instance method.
 * Ability to run simulations using mesa models
 * The `soil.exporters` module to export the results of datacollectors (`model.datacollector`) into files at the end of trials/simulations
-* Agents can now have generators as a step function or a state. They work similar to normal functions, with one caveat in the case of `FSM`: only `time` values (or None) can be yielded, not a state. This is because the state will not change, it will be resumed after the yield, at the appropriate time. The return value *can* be a state, or a `(state, time)` tuple, just like in normal states.
+* Agents can now have generators or async functions as their step or as states. They work similar to normal functions, with one caveat in the case of `FSM`: only time values (a float, int or None) can be awaited or yielded, not a state. This is because the state will not change, it will be resumed after the yield, at the appropriate time. To return to a different state, use the `delay` and `at` functions of the state.
 * Simulations can now specify a `matrix` with possible values for every simulation parameter. The final parameters will be calculated based on the `parameters` used and a cartesian product (i.e., all possible combinations) of each parameter.
 * Simple debugging capabilities in `soil.debugging`, with a custom `pdb.Debugger` subclass that exposes commands to list agents and their status and set breakpoints on states (for FSM agents). Try it with `soil --debug <simulation file>`
+* The `agent.after` and `agent.at` methods, to avoid having to return a time manually.
 ### Changed
 * Configuration schema (`Simulation`) is very simplified. All simulations should be checked
+* Agents that wish to 
 * Model / environment variables are expected (but not enforced) to be a single value. This is done to more closely align with mesa
 * `Exporter.iteration_end` now takes two parameters: `env` (same as before) and `params` (specific parameters for this environment). We considered including a `parameters` attribute in the environment, but this would not be compatible with mesa.
 * `num_trials` renamed to `iterations`
@@ -26,6 +28,7 @@ For an explanation of the general changes in version 1.0, please refer to the fi
 * Simulation results for every iteration of a simulation with the same name are stored in a single `sqlite` database
 
 ### Removed
+* The `time.When` and `time.Cond` classes are removed
 * Any `tsih` and `History` integration in the main classes. To record the state of environments/agents, just use a datacollector. In some cases this may be slower or consume more memory than the previous system. However, few cases actually used the full potential of the history, and it came at the cost of unnecessary complexity and worse performance for the majority of cases.
 
 ## [0.20.8]

docs/example.yml

@@ -1,40 +0,0 @@
----
-name: MyExampleSimulation
-max_time: 50
-num_trials: 3
-interval: 2
-model_params:
-  topology:
-    params:
-      generator: barabasi_albert_graph
-      n: 100
-      m: 2
-  agents:
-    distribution:
-    - agent_class: SISaModel
-      topology: True
-      ratio: 0.1
-      state:
-        state_id: content
-    - agent_class: SISaModel
-      topology: True
-      ratio: .1
-      state:
-        state_id: discontent
-    - agent_class: SISaModel
-      topology: True
-      ratio: 0.8
-      state:
-        state_id: neutral
-  prob_infect: 0.075
-  neutral_discontent_spon_prob: 0.1
-  neutral_discontent_infected_prob: 0.3
-  neutral_content_spon_prob: 0.3
-  neutral_content_infected_prob: 0.4
-  discontent_neutral: 0.5
-  discontent_content: 0.5
-  variance_d_c: 0.2
-  content_discontent: 0.2
-  variance_c_d: 0.2
-  content_neutral: 0.2
-  standard_variance: 1

docs/index.rst

@@ -2,7 +2,7 @@ Welcome to Soil's documentation!
 ================================
 
 Soil is an opinionated Agent-based Social Simulator in Python focused on Social Networks.
-To get started developing your own simulations and agent behaviors, check out our :doc:`Tutorial <soil_tutorial>` and the `examples on GitHub <https://github.com/gsi-upm/soil/tree/master/examples>`.
+To get started developing your own simulations and agent behaviors, check out our :doc:`Tutorial <tutorial/soil_tutorial>` and the `examples on GitHub <https://github.com/gsi-upm/soil/tree/master/examples>`.
 
 Soil can be installed through pip (see more details in the :doc:`installation` page):.
 
@@ -49,6 +49,7 @@ If you use Soil in your research, do not forget to cite this paper:
    installation
    Tutorial <tutorial/soil_tutorial>
    notes_v1.0
+   soil-vs
 
 ..
 

docs/mesa.rst

@@ -1,22 +0,0 @@
-Mesa compatibility
-------------------
-
-Soil is in the process of becoming fully compatible with MESA.
-The idea is to provide a set of modular classes and functions that extend the functionality of mesa, whilst staying compatible.
-In the end, it should be possible to add regular mesa agents to a soil simulation, or use a soil agent within a mesa simulation/model.
-
-This is a non-exhaustive list of tasks to achieve compatibility:
-
-- [ ] Integrate `soil.Simulation` with mesa's runners:
-  - [ ] `soil.Simulation` could mimic/become a `mesa.batchrunner`
-- [ ] Integrate `soil.Environment` with `mesa.Model`:
-  - [x] `Soil.Environment` inherits from `mesa.Model`
-  - [x] `Soil.Environment` includes a Mesa-like Scheduler (see the `soil.time` module.
-  - [ ] Allow for `mesa.Model` to be used in a simulation.
-- [ ] Integrate `soil.Agent` with `mesa.Agent`:
-  - [x] Rename agent.id to unique_id?
-  - [x] mesa agents can be used in soil simulations (see `examples/mesa`)
-- [ ] Provide examples
-  - [ ] Using mesa modules in a soil simulation
-  - [ ] Using soil modules in a mesa simulation
-- [ ] Document the new APIs and usage

docs/soil-vs.rst

@@ -1,4 +1,8 @@
-### MESA
+Soil vs other ABM frameworks
+============================
+
+MESA
+----
 
 Starting with version 0.3, Soil has been redesigned to complement Mesa, while remaining compatible with it.
 That means that every component in Soil (i.e., Models, Environments, etc.) can be mixed with existing mesa components.
@@ -10,3 +14,42 @@ Here are some reasons to use Soil instead of plain mesa:
 - Functions to automatically populate a topology with an agent distribution (i.e., different ratios of agent class and state)
 - The `soil.Simulation` class allows you to run multiple instances of the same experiment (i.e., multiple trials with the same parameters but a different randomness seed)
 - Reporting functions that aggregate multiple
+
+Mesa compatibility
+~~~~~~~~~~~~~~~~~~
+
+Soil is in the process of becoming fully compatible with MESA.
+The idea is to provide a set of modular classes and functions that extend the functionality of mesa, whilst staying compatible.
+In the end, it should be possible to add regular mesa agents to a soil simulation, or use a soil agent within a mesa simulation/model.
+
+This is a non-exhaustive list of tasks to achieve compatibility:
+
+.. |check| raw:: html
+
+    ☑
+
+.. |uncheck| raw:: html
+
+    ☐
+
+- |check| Integrate `soil.Simulation` with mesa's runners:
+
+  - |check| `soil.Simulation` can replace `mesa.batchrunner`
+
+- |check| Integrate `soil.Environment` with `mesa.Model`:
+
+  - |check| `Soil.Environment` inherits from `mesa.Model`
+  - |check| `Soil.Environment` includes a Mesa-like Scheduler (see the `soil.time` module.
+  - |check| Allow for `mesa.Model` to be used in a simulation.
+
+- |check| Integrate `soil.Agent` with `mesa.Agent`:
+
+  - |check| Rename agent.id to unique_id
+  - |check| mesa agents can be used in soil simulations (see `examples/mesa`)
+
+- |check| Provide examples
+
+  - |check| Using mesa modules in a soil simulation (see `examples/mesa`)
+  - |uncheck| Using soil modules in a mesa simulation (see `examples/mesa`)
+
+- |uncheck| Document the new APIs and usage

examples/README.md

@@ -0,0 +1 @@
+Some of these examples are close to real life simulations, whereas some others are only a demonstration of Soil's capatibilities.

examples/cars/cars_sim.py

@@ -86,7 +86,7 @@ class Driver(Evented, FSM):
     earnings = 0
 
     def on_receive(self, msg, sender):
-        """This is not a state. It will run (and block) every time check_messages is invoked"""
+        """This is not a state. It will run (and block) every time process_messages is invoked"""
         if self.journey is None and isinstance(msg, Journey) and msg.driver is None:
             msg.driver = self
             self.journey = msg
@@ -95,15 +95,14 @@ class Driver(Evented, FSM):
         """If there are no more passengers, stop forever"""
         c = self.count_agents(agent_class=Passenger)
         self.debug(f"Passengers left {c}")
-        if not c:
+        return c
-            self.die("No more passengers")
 
-    @default_state
+    @state(default=True)
-    @state
+    async def wandering(self):
-    def wandering(self):
         """Move around the city until a journey is accepted"""
         target = None
-        self.check_passengers()
+        if not self.check_passengers():
+            return self.die("No passengers left")
         self.journey = None
         while self.journey is None:  # No potential journeys detected (see on_receive)
             if target is None or not self.move_towards(target):
@@ -111,14 +110,15 @@ class Driver(Evented, FSM):
                     self.model.grid.get_neighborhood(self.pos, moore=False)
                 )
 
-            self.check_passengers()
+            if not self.check_passengers():
+                return self.die("No passengers left")
             # This will call on_receive behind the scenes, and the agent's status will be updated
-            self.check_messages()
+            self.process_messages()
-            yield Delta(30)  # Wait at least 30 seconds before checking again
+            await self.delay(30)  # Wait at least 30 seconds before checking again
 
         try:
             # Re-send the journey to the passenger, to confirm that we have been selected
-            self.journey = yield self.journey.passenger.ask(self.journey, timeout=60)
+            self.journey = await self.journey.passenger.ask(self.journey, timeout=60, delay=5)
         except events.TimedOut:
             # No journey has been accepted. Try again
             self.journey = None
@@ -127,18 +127,19 @@ class Driver(Evented, FSM):
         return self.driving
 
     @state
-    def driving(self):
+    async def driving(self):
         """The journey has been accepted. Pick them up and take them to their destination"""
         self.info(f"Driving towards Passenger {self.journey.passenger.unique_id}")
         while self.move_towards(self.journey.origin):
-            yield
+            await self.delay()
         self.info(f"Driving {self.journey.passenger.unique_id} from {self.journey.origin} to {self.journey.destination}")
         while self.move_towards(self.journey.destination, with_passenger=True):
-            yield
+            await self.delay()
         self.info("Arrived at destination")
         self.earnings += self.journey.tip
         self.model.total_earnings += self.journey.tip
-        self.check_passengers()
+        if not self.check_passengers():
+            return self.die("No passengers left")
         return self.wandering
 
     def move_towards(self, target, with_passenger=False):
@@ -167,7 +168,7 @@ class Passenger(Evented, FSM):
     pos = None
 
     def on_receive(self, msg, sender):
-        """This is not a state. It will be run synchronously every time `check_messages` is run"""
+        """This is not a state. It will be run synchronously every time `process_messages` is run"""
 
         if isinstance(msg, Journey):
             self.journey = msg
@@ -175,7 +176,7 @@ class Passenger(Evented, FSM):
 
     @default_state
     @state
-    def asking(self):
+    async def asking(self):
         destination = (
             self.random.randint(0, self.model.grid.height-1),
             self.random.randint(0, self.model.grid.width-1),
@@ -195,9 +196,9 @@ class Passenger(Evented, FSM):
         while not self.journey:
             self.debug(f"Waiting for responses at: { self.pos }")
             try:
-                # This will call check_messages behind the scenes, and the agent's status will be updated
+                # This will call process_messages behind the scenes, and the agent's status will be updated
                 # If you want to avoid that, you can call it with: check=False
-                yield self.received(expiration=expiration)
+                await self.received(expiration=expiration, delay=10)
             except events.TimedOut:
                 self.info(f"Still no response. Waiting at: { self.pos }")
                 self.model.broadcast(
@@ -208,13 +209,13 @@ class Passenger(Evented, FSM):
         return self.driving_home
 
     @state
-    def driving_home(self):
+    async def driving_home(self):
         while (
             self.pos[0] != self.journey.destination[0]
             or self.pos[1] != self.journey.destination[1]
         ):
             try:
-                yield self.received(timeout=60)
+                await self.received(timeout=60)
             except events.TimedOut:
                 pass
 

examples/custom_generator/generator_sim.py

@@ -33,7 +33,7 @@ class GeneratorEnv(Environment):
         self.add_agents(CounterModel)
 
 
-sim = Simulation(model=GeneratorEnv, max_steps=10, interval=1)
+sim = Simulation(model=GeneratorEnv, max_steps=10)
 
 if __name__ == '__main__':
     sim.run(dump=False)

examples/custom_timeouts/custom_timeouts_sim.py

@@ -1,5 +1,4 @@
 from soil.agents import FSM, state, default_state
-from soil.time import Delta
 
 
 class Fibonacci(FSM):
@@ -11,17 +10,17 @@ class Fibonacci(FSM):
     def counting(self):
         self.log("Stopping at {}".format(self.now))
         prev, self["prev"] = self["prev"], max([self.now, self["prev"]])
-        return None, Delta(prev)
+        return self.delay(prev)
+    
 
 
 class Odds(FSM):
     """Agent that only executes in odd t_steps"""
 
-    @default_state
+    @state(default=True)
-    @state
     def odds(self):
         self.log("Stopping at {}".format(self.now))
-        return None, Delta(1 + self.now % 2)
+        return self.delay(1 + (self.now % 2))
 
 
 from soil import Environment, Simulation
@@ -35,7 +34,7 @@ class TimeoutsEnv(Environment):
         self.add_agent(agent_class=Odds, node_id=1)
 
 
-sim = Simulation(model=TimeoutsEnv, max_steps=10, interval=1)
+sim = Simulation(model=TimeoutsEnv, max_steps=10)
 
 if __name__ == "__main__":
     sim.run(dump=False)

examples/mesa/mesa_sim.py

@@ -1,7 +1,7 @@
 from soil import Simulation
 from social_wealth import MoneyEnv, graph_generator
 
-sim = Simulation(name="mesa_sim", dump=False, max_steps=10, interval=2, model=MoneyEnv, parameters=dict(generator=graph_generator, N=10, width=50, height=50))
+sim = Simulation(name="mesa_sim", dump=False, max_steps=10, model=MoneyEnv, parameters=dict(generator=graph_generator, N=10, width=50, height=50))
 
 if __name__ == "__main__":
     sim.run()

examples/rabbits/rabbit_improved_sim.py

@@ -1,5 +1,4 @@
 from soil import FSM, state, default_state, BaseAgent, NetworkAgent, Environment, Simulation
-from soil.time import Delta
 from enum import Enum
 from collections import Counter
 import logging
@@ -35,7 +34,7 @@ class Rabbit(FSM, NetworkAgent):
         self.info("I am a newborn.")
         self.birth = self.now
         self.offspring = 0
-        return self.youngling, Delta(self.sexual_maturity - self.age)
+        return self.youngling.delay(self.sexual_maturity - self.age)
 
     @state
     def youngling(self):

examples/random_delays/random_delays_sim.py

@@ -1,9 +1,7 @@
 """
-Example of setting a 
 Example of a fully programmatic simulation, without definition files.
 """
 from soil import Simulation, agents, Environment
-from soil.time import Delta
 
 
 class MyAgent(agents.FSM):
@@ -11,22 +9,22 @@ class MyAgent(agents.FSM):
     An agent that first does a ping
     """
 
-    defaults = {"pong_counts": 2}
+    max_pongs = 2
 
     @agents.default_state
     @agents.state
     def ping(self):
         self.info("Ping")
-        return self.pong, Delta(self.random.expovariate(1 / 16))
+        return self.pong.delay(self.random.expovariate(1 / 16))
 
     @agents.state
     def pong(self):
         self.info("Pong")
-        self.pong_counts -= 1
+        self.max_pongs -= 1
-        self.info(str(self.pong_counts))
+        self.info(str(self.max_pongs), "pongs remaining")
-        if self.pong_counts < 1:
+        if self.max_pongs < 1:
             return self.die()
-        return None, Delta(self.random.expovariate(1 / 16))
+        return self.delay(self.random.expovariate(1 / 16))
 
 
 class RandomEnv(Environment):

examples/terrorism/TerroristNetworkModel_sim.py

@@ -1,5 +1,6 @@
 import networkx as nx
-from soil.agents import Geo, NetworkAgent, FSM, custom, state, default_state
+from soil.agents import NetworkAgent, FSM, custom, state, default_state
+from soil.agents.geo import Geo
 from soil import Environment, Simulation
 from soil.parameters import *
 from soil.utils import int_seed
@@ -39,8 +40,8 @@ class TerroristEnvironment(Environment):
             HavenModel
         ], [self.ratio_civil, self.ratio_leader, self.ratio_training, self.ratio_haven])
 
-    def generator(self, *args, **kwargs):
+    def generator(self, *args, seed=None, **kwargs):
-        return nx.random_geometric_graph(*args, **kwargs, seed=int_seed(self._seed))
+        return nx.random_geometric_graph(*args, **kwargs, seed=seed or int_seed(self._seed))
 
 class TerroristSpreadModel(FSM, Geo):
     """

examples/torvalds_sim.py

@@ -21,5 +21,4 @@ class TorvaldsEnv(Environment):
 
 sim = Simulation(name='torvalds_example',
                  max_steps=10,
-                 interval=2,
                  model=TorvaldsEnv)

soil/VERSION

@@ -1 +1 @@
-1.0.0rc2
+1.0.0rc3

soil/__init__.py

@@ -16,7 +16,6 @@ except NameError:
     basestring = str
 
 from pathlib import Path
-from .analysis import *
 from .agents import *
 from . import agents
 from .simulation import *

soil/agents/__init__.py

@@ -25,6 +25,35 @@ from .. import serialization, network, utils, time, config
 IGNORED_FIELDS = ("model", "logger")
 
 
+def decorate_generator_step(func, name):
+    @wraps(func)
+    def decorated(self):
+        while True:
+            if self._coroutine is None:
+                self._coroutine = func(self)
+            try:
+                if self._last_except:
+                    val = self._coroutine.throw(self._last_except)
+                else:
+                    val = self._coroutine.send(self._last_return)
+            except StopIteration as ex:
+                self._coroutine = None
+                val = ex.value
+            finally:
+                self._last_return = None
+                self._last_except = None
+            return float(val) if val is not None else val
+    return decorated
+
+
+def decorate_normal_func(func, name):
+    @wraps(func)
+    def decorated(self):
+        val = func(self)
+        return float(val) if val is not None else val
+    return decorated
+
+
 class MetaAgent(ABCMeta):
     def __new__(mcls, name, bases, namespace):
         defaults = {}
@@ -36,34 +65,23 @@ class MetaAgent(ABCMeta):
 
         new_nmspc = {
             "_defaults": defaults,
-            "_last_return": None,
-            "_last_except": None,
         }
 
         for attr, func in namespace.items():
-            if attr == "step" and inspect.isgeneratorfunction(func):
+            if attr == "step":
-                orig_func = func
+                if inspect.isgeneratorfunction(func) or inspect.iscoroutinefunction(func):
-                new_nmspc["_coroutine"] = None
+                    func = decorate_generator_step(func, attr)
-
+                    new_nmspc.update({
-                @wraps(func)
+                        "_last_return": None,
-                def func(self):
+                        "_last_except": None,
-                    while True:
+                        "_coroutine": None,
-                        if not self._coroutine:
+                    })
-                            self._coroutine = orig_func(self)
+                elif inspect.isasyncgenfunction(func):
-                        try:
+                    raise ValueError("Illegal step function: {}. It probably mixes both async/await and yield".format(func))
-                            if self._last_except:
+                elif inspect.isfunction(func):
-                                return self._coroutine.throw(self._last_except)
+                    func = decorate_normal_func(func, attr)
-                            else:
+                else:
-                                return self._coroutine.send(self._last_return)
+                    raise ValueError("Illegal step function: {}".format(func))
-                        except StopIteration as ex:
-                            self._coroutine = None
-                            return ex.value
-                        finally:
-                            self._last_return = None
-                            self._last_except = None
-
-                func.id = name or func.__name__
-                func.is_default = False
                 new_nmspc[attr] = func
             elif (
                 isinstance(func, types.FunctionType)
@@ -74,9 +92,13 @@ class MetaAgent(ABCMeta):
                 new_nmspc[attr] = func
             elif attr == "defaults":
                 defaults.update(func)
+            elif inspect.isfunction(func):
+                new_nmspc[attr] = func
             else:
                 defaults[attr] = copy(func)
 
+
+        # Add attributes for their use in the decorated functions
         return super().__new__(mcls, name, bases, new_nmspc)
 
 
@@ -92,7 +114,7 @@ class BaseAgent(MesaAgent, MutableMapping, metaclass=MetaAgent):
     Any attribute that is not preceded by an underscore (`_`) will also be added to its state.
     """
 
-    def __init__(self, unique_id, model, name=None, init=True, interval=None, **kwargs):
+    def __init__(self, unique_id, model, name=None, init=True, **kwargs):
         assert isinstance(unique_id, int)
         super().__init__(unique_id=unique_id, model=model)
 
@@ -102,7 +124,6 @@ class BaseAgent(MesaAgent, MutableMapping, metaclass=MetaAgent):
 
         self.alive = True
 
-        self.interval = interval or self.get("interval", 1)
         logger = utils.logger.getChild(getattr(self.model, "id", self.model)).getChild(
             self.name
         )
@@ -111,13 +132,18 @@ class BaseAgent(MesaAgent, MutableMapping, metaclass=MetaAgent):
         if hasattr(self, "level"):
             self.logger.setLevel(self.level)
 
+        for k in self._defaults:
+            v = getattr(model, k, None)
+            if v is not None:
+                setattr(self, k, v)
+
         for (k, v) in self._defaults.items():
             if not hasattr(self, k) or getattr(self, k) is None:
                 setattr(self, k, deepcopy(v))
 
         for (k, v) in kwargs.items():
-
             setattr(self, k, v)
+
         if init:
             self.init()
 
@@ -189,11 +215,13 @@ class BaseAgent(MesaAgent, MutableMapping, metaclass=MetaAgent):
         return it
 
     def get(self, key, default=None):
-        if key in self:
+        try:
-            return self[key]
+            return getattr(self, key)
-        elif key in self.model:
+        except AttributeError:
-            return self.model[key]
+            try:
-        return default
+                return getattr(self.model, key)
+            except AttributeError:
+                return default
 
     @property
     def now(self):
@@ -206,13 +234,14 @@ class BaseAgent(MesaAgent, MutableMapping, metaclass=MetaAgent):
     def die(self, msg=None):
         if msg:
             self.info("Agent dying:", msg)
-        self.debug(f"agent dying")
+        else:
+            self.debug(f"agent dying")
         self.alive = False
         try:
             self.model.schedule.remove(self)
         except KeyError:
             pass
-        return time.NEVER
+        return time.Delay(time.INFINITY)
 
     def step(self):
         raise NotImplementedError("Agent must implement step method")
@@ -266,6 +295,12 @@ class BaseAgent(MesaAgent, MutableMapping, metaclass=MetaAgent):
     def __repr__(self):
         return f"{self.__class__.__name__}({self.unique_id})"
     
+    def at(self, at):
+        return time.Delay(float(at) - self.now)
+    
+    def delay(self, delay=1):
+        return time.Delay(delay)
+
 
 def prob(prob, random):
     """
@@ -450,8 +485,10 @@ def filter_agents(
     state = state or dict()
     state.update(kwargs)
 
-    for k, v in state.items():
+    for k, vs in state.items():
-        f = filter(lambda agent: getattr(agent, k, None) == v, f)
+        if not isinstance(vs, list):
+            vs = [vs]
+        f = filter(lambda agent: any(getattr(agent, k, None) == v for v in vs), f)
 
     if limit is not None:
         f = islice(f, limit)
@@ -658,15 +695,6 @@ from .SISaModel import *
 from .CounterModel import *
 
 
-try:
-    import scipy
-    from .Geo import Geo
-except ImportError:
-    import sys
-
-    print("Could not load the Geo Agent, scipy is not installed", file=sys.stderr)
-
-
 def custom(cls, **kwargs):
     """Create a new class from a template class and keyword arguments"""
     return type(cls.__name__, (cls,), kwargs)

soil/agents/evented.py

@@ -1,42 +1,8 @@
 from . import BaseAgent
 from ..events import Message, Tell, Ask, TimedOut
-from ..time import BaseCond
 from functools import partial
 from collections import deque
-
+from types import coroutine
-
-class ReceivedOrTimeout(BaseCond):
-    def __init__(
-        self, agent, expiration=None, timeout=None, check=True, ignore=False, **kwargs
-    ):
-        if expiration is None:
-            if timeout is not None:
-                expiration = agent.now + timeout
-        self.expiration = expiration
-        self.ignore = ignore
-        self.check = check
-        super().__init__(**kwargs)
-
-    def expired(self, time):
-        return self.expiration and self.expiration < time
-
-    def ready(self, agent, time):
-        return len(agent._inbox) or self.expired(time)
-
-    def return_value(self, agent):
-        if not self.ignore and self.expired(agent.now):
-            raise TimedOut("No messages received")
-        if self.check:
-            agent.check_messages()
-        return None
-
-    def schedule_next(self, time, delta, first=False):
-        if self._delta is not None:
-            delta = self._delta
-        return (time + delta, self)
-
-    def __repr__(self):
-        return f"ReceivedOrTimeout(expires={self.expiration})"
 
 
 class EventedAgent(BaseAgent):
@@ -48,30 +14,45 @@ class EventedAgent(BaseAgent):
     def on_receive(self, *args, **kwargs):
         pass
 
-    def received(self, *args, **kwargs):
+    @coroutine
-        return ReceivedOrTimeout(self, *args, **kwargs)
+    def received(self, expiration=None, timeout=60, delay=1, process=True):
+        if not expiration:
+            expiration = self.now + timeout
+        while self.now < expiration:
+            if self._inbox:
+                msgs = self._inbox
+                if process:
+                    self.process_messages()
+                return msgs
+            yield self.delay(delay)
+        raise TimedOut("No message received")
 
     def tell(self, msg, sender=None):
         self._inbox.append(Tell(timestamp=self.now, payload=msg, sender=sender))
 
-    def ask(self, msg, timeout=None, **kwargs):
+    @coroutine
+    def ask(self, msg, expiration=None, timeout=None, delay=1):
         ask = Ask(timestamp=self.now, payload=msg, sender=self)
         self._inbox.append(ask)
         expiration = float("inf") if timeout is None else self.now + timeout
-        return ask.replied(expiration=expiration, **kwargs)
+        while self.now < expiration:
+            if ask.reply:
+                return ask.reply
+            yield self.delay(delay)
+        raise TimedOut("No reply received")
 
-    def check_messages(self):
+    def process_messages(self):
-        changed = False
+        valid = list()
-        while self._inbox:
+        for msg in self._inbox:
-            msg = self._inbox.popleft()
             self._processed += 1
             if msg.expired(self.now):
                 continue
-            changed = True
+            valid.append(msg)
             reply = self.on_receive(msg.payload, sender=msg.sender)
             if isinstance(msg, Ask):
                 msg.reply = reply
-        return changed
+        self._inbox.clear()
+        return valid
 
 
 Evented = EventedAgent

soil/agents/fsm.py

@@ -1,47 +1,69 @@
 from . import MetaAgent, BaseAgent
-from ..time import Delta
+from .. import time
-
+from types import coroutine
 from functools import partial, wraps
 import inspect
 
 
+class State:
+    __slots__ = ("awaitable", "f", "generator", "name", "default")
+
+    def __init__(self, f, name, default, generator, awaitable):
+        self.f = f
+        self.name = name
+        self.generator = generator
+        self.awaitable = awaitable
+        self.default = default
+
+    @coroutine
+    def step(self, obj):
+        if self.generator or self.awaitable:
+            f = self.f
+            next_state = yield from f(obj)
+            return next_state
+
+        else:
+            return self.f(obj)
+
+    @property
+    def id(self):
+        return self.name
+
+    def __call__(self, *args, **kwargs):
+        raise Exception("States should not be called directly")
+
+class UnboundState(State):
+
+    def bind(self, obj):
+        bs = BoundState(self.f, self.name, self.default, self.generator, self.awaitable, obj=obj)
+        setattr(obj, self.name, bs)
+        return bs
+
+
+class BoundState(State):
+    __slots__ = ("obj", )
+
+    def __init__(self, *args, obj):
+        super().__init__(*args)
+        self.obj = obj
+    
+    def delay(self, delta=0):
+        return self, self.obj.delay(delta)
+    
+    def at(self, when):
+        return self, self.obj.at(when)
+
+
 def state(name=None, default=False):
     def decorator(func, name=None):
         """
         A state function should return either a state id, or a tuple (state_id, when)
         The default value for state_id is the current state id.
-        The default value for when is the interval defined in the environment.
         """
-        if inspect.isgeneratorfunction(func):
+        name = name or func.__name__
-            orig_func = func
+        generator = inspect.isgeneratorfunction(func)
-
+        awaitable = inspect.iscoroutinefunction(func) or inspect.isasyncgen(func)
-            @wraps(func)
+        return UnboundState(func, name, default, generator, awaitable)
-            def func(self):
-                while True:
-                    if not self._coroutine:
-                        self._coroutine = orig_func(self)
-
-                    try:
-                        if self._last_except:
-                            n = self._coroutine.throw(self._last_except)
-                        else:
-                            n = self._coroutine.send(self._last_return)
-                        if n:
-                            return None, n
-                        return n
-                    except StopIteration as ex:
-                        self._coroutine = None
-                        next_state = ex.value
-                        if next_state is not None:
-                            self._set_state(next_state)
-                        return next_state
-                    finally:
-                        self._last_return = None
-                        self._last_except = None
-
-        func.id = name or func.__name__
-        func.is_default = default
-        return func
 
     if callable(name):
         return decorator(name)
@@ -50,7 +72,7 @@ def state(name=None, default=False):
 
 
 def default_state(func):
-    func.is_default = True
+    func.default = True
     return func
 
 
@@ -62,42 +84,45 @@ class MetaFSM(MetaAgent):
         for i in bases:
             if isinstance(i, MetaFSM):
                 for state_id, state in i._states.items():
-                    if state.is_default:
+                    if state.default:
                         default_state = state
                     states[state_id] = state
 
         # Add new states
         for attr, func in namespace.items():
-            if hasattr(func, "id"):
+            if isinstance(func, State):
-                if func.is_default:
+                if func.default:
                     default_state = func
-                states[func.id] = func
+                states[func.name] = func
 
         namespace.update(
             {
-                "_default_state": default_state,
+                "_state": default_state,
                 "_states": states,
             }
         )
 
-        return super(MetaFSM, mcls).__new__(
+        cls = super(MetaFSM, mcls).__new__(
             mcls=mcls, name=name, bases=bases, namespace=namespace
         )
+        for (k, v) in states.items():
+            setattr(cls, k, v)
+        return cls
 
 
 class FSM(BaseAgent, metaclass=MetaFSM):
-    def __init__(self, init=True, **kwargs):
+    def __init__(self, init=True, state_id=None, **kwargs):
         super().__init__(**kwargs, init=False)
-        if not hasattr(self, "state_id"):
+        if state_id is not None:
-            if not self._default_state:
+            self._set_state(state_id)
-                raise ValueError(
+        # If more than "dead" state is defined, but no default state
-                    "No default state specified for {}".format(self.unique_id)
+        if len(self._states) > 1 and not self._state:
-                )
+            raise ValueError(
-            self.state_id = self._default_state.id
+                f"No default state specified for {type(self)}({self.unique_id})"
+            )
+        for (k, v) in self._states.items():
+            setattr(self, k, v.bind(self))
 
-        self._coroutine = None
-        self.default_interval = Delta(self.model.interval)
-        self._set_state(self.state_id)
         if init:
             self.init()
 
@@ -105,44 +130,46 @@ class FSM(BaseAgent, metaclass=MetaFSM):
     def states(cls):
         return list(cls._states.keys())
 
+    @property
+    def state_id(self):
+        return self._state.name
+    
+    def set_state(self, value):
+        if self.now > 0:
+            raise ValueError("Cannot change state after init")
+        self._set_state(value)
+
     def step(self):
-        self.debug(f"Agent {self.unique_id} @ state {self.state_id}")
-
         self._check_alive()
-        next_state = self._states[self.state_id](self)
+        next_state = yield from self._state.step(self)
 
-        when = None
         try:
-            next_state, *when = next_state
+            next_state, when = next_state
-            if not when:
+        except (TypeError, ValueError) as ex:
-                when = None
+            try:
-            elif len(when) == 1:
+                self._set_state(next_state)
-                when = when[0]
+                return None
-            else:
+            except ValueError:
-                raise ValueError(
+                return next_state
-                    "Too many values returned. Only state (and time) allowed"
-                )
-        except TypeError:
-            pass
 
-        if next_state is not None:
+        self._set_state(next_state)
-            self._set_state(next_state)
+        return when
 
-        return when or self.default_interval
+    def _set_state(self, state):
-
+        if state is None:
-    def _set_state(self, state, when=None):
+            return
-        if hasattr(state, "id"):
+        if isinstance(state, str):
-            state = state.id
+            if state not in self._states:
-        if state not in self._states:
+                raise ValueError("{} is not a valid state".format(state))
+            state = self._states[state]
+        if not isinstance(state, State):
             raise ValueError("{} is not a valid state".format(state))
-        self.state_id = state
+        self._state = state
-        if when is not None:
-            self.model.schedule.add(self, when=when)
-        return state
 
     def die(self, *args, **kwargs):
-        return self.dead, super().die(*args, **kwargs)
+        super().die(*args, **kwargs)
+        return self.dead.at(time.INFINITY)
 
     @state
     def dead(self):
-        return self.die()
+        return time.INFINITY

soil/agents/network_agents.py

@@ -6,7 +6,7 @@ class NetworkAgent(BaseAgent):
         super().__init__(*args, init=False, **kwargs)
 
         self.G = topology or self.model.G
-        assert self.G
+        assert self.G is not None, "Network agents should have a network"
         if node_id is None:
             nodes = self.random.choices(list(self.G.nodes), k=len(self.G))
             for n_id in nodes:
@@ -25,8 +25,6 @@ class NetworkAgent(BaseAgent):
 
     def count_neighbors(self, state_id=None, **kwargs):
         return len(self.get_neighbors(state_id=state_id, **kwargs))
-        if init:
-            self.init()
 
     def iter_neighbors(self, **kwargs):
         return self.iter_agents(limit_neighbors=True, **kwargs)

soil/analysis.py

@@ -28,7 +28,8 @@ def plot(env, agent_df=None, model_df=None, steps=False, ignore=["agent_count",
 
 
 Results = namedtuple("Results", ["config", "parameters", "env", "agents"])
-#TODO implement reading from CSV and SQLITE
+#TODO implement reading from CSV
+
 def read_sql(fpath=None, name=None, include_agents=False):
     if not (fpath is None) ^ (name is None):
         raise ValueError("Specify either a path or a simulation name")

soil/datacollection.py

@@ -9,7 +9,7 @@ class SoilCollector(MDC):
         if 'agent_count' not in model_reporters:
             model_reporters['agent_count'] = lambda m: m.schedule.get_agent_count()
         if 'time' not in model_reporters:
-            model_reporters['time'] = lambda m: m.now
+            model_reporters['time'] = lambda m: m.schedule.time
         # if 'state_id' not in agent_reporters:
         #     agent_reporters['state_id'] = lambda agent: getattr(agent, 'state_id', None)
 

soil/environment.py

@@ -16,7 +16,7 @@ import networkx as nx
 
 from mesa import Model, Agent
 
-from . import agents as agentmod, datacollection, serialization, utils, time, network, events
+from . import agents as agentmod, datacollection, utils, time, network, events
 
 
 # TODO: maybe add metaclass to read attributes of a model
@@ -35,6 +35,7 @@ class BaseEnvironment(Model):
     """
 
     collector_class = datacollection.SoilCollector
+    schedule_class = time.TimedActivation
 
     def __new__(cls,
                 *args: Any,
@@ -49,7 +50,6 @@ class BaseEnvironment(Model):
         self = super().__new__(cls, *args, seed=seed, **kwargs)
         self.dir_path = dir_path or os.getcwd()
         collector_class = collector_class or cls.collector_class
-        collector_class = serialization.deserialize(collector_class)
         self.datacollector = collector_class(
             model_reporters=model_reporters,
             agent_reporters=agent_reporters,
@@ -60,7 +60,7 @@ class BaseEnvironment(Model):
             if isinstance(v, property):
                 v = v.fget
             if getattr(v, "add_to_report", False):
-                self.add_model_reporter(k, v)
+                self.add_model_reporter(k, k)
 
         return self
 
@@ -70,8 +70,8 @@ class BaseEnvironment(Model):
         id="unnamed_env",
         seed="default",
         dir_path=None,
-        schedule_class=time.TimedActivation,
+        schedule=None,
-        interval=1,
+        schedule_class=None,
         logger = None,
         agents: Optional[Dict] = None,
         collector_class: type = datacollection.SoilCollector,
@@ -94,13 +94,11 @@ class BaseEnvironment(Model):
         else:
             self.logger = utils.logger.getChild(self.id)
 
-        if schedule_class is None:
+        self.schedule = schedule
-            schedule_class = time.TimedActivation
+        if schedule is None:
-        else:
+            if schedule_class is None:
-            schedule_class = serialization.deserialize(schedule_class)
+                schedule_class = self.schedule_class
-
+            self.schedule = schedule_class(self)
-        self.interval = interval
-        self.schedule = schedule_class(self)
 
         for (k, v) in env_params.items():
             self[k] = v
@@ -161,7 +159,7 @@ class BaseEnvironment(Model):
         if unique_id is None:
             unique_id = self.next_id()
 
-        a = serialization.deserialize(agent_class)(unique_id=unique_id, model=self, **agent)
+        a = agent_class(unique_id=unique_id, model=self, **agent)
 
         self.schedule.add(a)
         return a
@@ -204,14 +202,14 @@ class BaseEnvironment(Model):
 
     def add_model_reporter(self, name, func=None):
         if not func:
-            func = lambda env: getattr(env, name)
+            func = name
         self.datacollector._new_model_reporter(name, func)
 
-    def add_agent_reporter(self, name, agent_type=None):
+    def add_agent_reporter(self, name, reporter=None, agent_type=None):
-        if agent_type:
+        if not agent_type and not reporter:
-            reporter = lambda a: getattr(a, name) if isinstance(a, agent_type) else None
+            reporter = name
-        else:
+        elif agent_type:
-            reporter = lambda a: getattr(a, name, None)
+            reporter = lambda a: reporter(a) if isinstance(a, agent_type) else None
         self.datacollector._new_agent_reporter(name, reporter)
 
     @classmethod
@@ -278,8 +276,6 @@ class NetworkEnvironment(BaseEnvironment):
         super().__init__(*args, **kwargs, init=False)
 
         self.agent_class = agent_class
-        if agent_class:
-            self.agent_class = serialization.deserialize(agent_class)
         if self.agent_class:
             self.populate_network(self.agent_class)
         self._check_agent_nodes()
@@ -309,7 +305,15 @@ class NetworkEnvironment(BaseEnvironment):
         elif path is not None:
             topology = network.from_topology(path, dir_path=self.dir_path)
         elif generator is not None:
-            topology = network.from_params(generator=generator, dir_path=self.dir_path, **network_params)
+            params = dict(generator=generator,
+                                           dir_path=self.dir_path,
+                                           seed=self.random,
+                                           **network_params)
+            try:
+                topology = network.from_params(**params)
+            except TypeError:
+                del params["seed"]
+                topology = network.from_params(**params)
         else:
             raise ValueError("topology must be a networkx.Graph or a string, or network_generator must be provided")
         self.G = topology

soil/events.py

@@ -1,4 +1,3 @@
-from .time import BaseCond
 from dataclasses import dataclass, field
 from typing import Any
 from uuid import uuid4
@@ -24,29 +23,9 @@ class Reply(Message):
     source: Message
 
 
-class ReplyCond(BaseCond):
-    def __init__(self, ask, *args, **kwargs):
-        self._ask = ask
-        super().__init__(*args, **kwargs)
-
-    def ready(self, agent, time):
-        return self._ask.reply is not None or self._ask.expired(time)
-
-    def return_value(self, agent):
-        if self._ask.expired(agent.now):
-            raise TimedOut()
-        return self._ask.reply
-
-    def __repr__(self):
-        return f"ReplyCond({self._ask.id})"
-
-
 class Ask(Message):
     reply: Message = None
 
-    def replied(self, expiration=None):
-        return ReplyCond(self)
-
 
 class Tell(Message):
     pass

soil/exporters.py

@@ -2,11 +2,9 @@ import os
 import sys
 from time import time as current_time
 from io import BytesIO
-from sqlalchemy import create_engine
 from textwrap import dedent, indent
 
 
-import matplotlib.pyplot as plt
 import networkx as nx
 import pandas as pd
 
@@ -124,6 +122,9 @@ class SQLite(Exporter):
         if not self.dump:
             logger.debug("NOT dumping results")
             return
+
+        from sqlalchemy import create_engine
+
         self.dbpath = os.path.join(self.outdir, f"{self.simulation.name}.sqlite")
         logger.info("Dumping results to %s", self.dbpath)
         if self.simulation.backup:
@@ -175,7 +176,6 @@ class csv(Exporter):
                     df.to_csv(f)
 
 
-# TODO: reimplement GEXF exporting without history
 class gexf(Exporter):
     def iteration_end(self, env, *args, **kwargs):
         if not self.dump:
@@ -186,8 +186,7 @@ class gexf(Exporter):
             "[GEXF] Dumping simulation {} iteration {}".format(self.simulation.name, env.id)
         ):
             with self.output("{}.gexf".format(env.id), mode="wb") as f:
-                network.dump_gexf(env.history_to_graph(), f)
+                nx.write_gexf(env.G, f)
-                self.dump_gexf(env, f)
 
 
 class dummy(Exporter):
@@ -210,6 +209,7 @@ class dummy(Exporter):
 
 class graphdrawing(Exporter):
     def iteration_end(self, env, *args, **kwargs):
+        import matplotlib.pyplot as plt
         # Outside effects
         f = plt.figure()
         nx.draw(

soil/serialization.py

@@ -103,7 +103,13 @@ def load_config(cfg):
         yield from load_files(cfg)
 
 
-builtins = importlib.import_module("builtins")
+_BUILTINS = None
+
+def builtins():
+    global _BUILTINS
+    if not _BUILTINS:
+        _BUILTINS = importlib.import_module("builtins")
+    return _BUILTINS
 
 KNOWN_MODULES = {
     'soil': None,
@@ -163,7 +169,7 @@ def name(value, known_modules=KNOWN_MODULES):
     if not isinstance(value, type):  # Get the class name first
         value = type(value)
     tname = value.__name__
-    if hasattr(builtins, tname):
+    if hasattr(builtins(), tname):
         return tname
     modname = value.__module__
     if modname == "__main__":
@@ -178,7 +184,7 @@ def name(value, known_modules=KNOWN_MODULES):
 
 
 def serializer(type_):
-    if type_ != "str" and hasattr(builtins, type_):
+    if type_ != "str":
         return repr
     return lambda x: x
 
@@ -216,8 +222,8 @@ def deserializer(type_, known_modules=KNOWN_MODULES):
         return lambda x="": x
     if type_ == "None":
         return lambda x=None: None
-    if hasattr(builtins, type_):  # Check if it's a builtin type
+    if hasattr(builtins(), type_):  # Check if it's a builtin type
-        cls = getattr(builtins, type_)
+        cls = getattr(builtins(), type_)
         return lambda x=None: ast.literal_eval(x) if x is not None else cls()
     match = IS_CLASS.match(type_)
     if match:

soil/simulation.py

@@ -23,7 +23,7 @@ import json
 
 
 from . import serialization, exporters, utils, basestring, agents
-from .environment import Environment
+from . import environment
 from .utils import logger, run_and_return_exceptions
 from .debugging import set_trace
 
@@ -49,8 +49,6 @@ def _iter_queued():
 
 
 # TODO: change documentation for simulation
-# TODO: rename iterations to iterations
-# TODO: make parameters a dict of iterable/any
 @dataclass
 class Simulation:
     """
@@ -68,7 +66,6 @@ class Simulation:
         dir_path: The directory path to use for the simulation.
         max_time: The maximum time to run the simulation.
         max_steps: The maximum number of steps to run the simulation.
-        interval: The interval to use for the simulation.
         iterations: The number of iterations (times) to run the simulation.
         num_processes: The number of processes to use for the simulation. If greater than one, simulations will be performed in parallel. This may make debugging and error handling difficult.
         tables: The tables to use in the simulation datacollector
@@ -96,7 +93,6 @@ class Simulation:
     dir_path: str = field(default_factory=lambda: os.getcwd())
     max_time: float = None
     max_steps: int = None
-    interval: int = 1
     iterations: int = 1
     num_processes: Optional[int] = 1
     exporters: Optional[List[str]] = field(default_factory=lambda: [exporters.default])
@@ -126,15 +122,9 @@ class Simulation:
             if isinstance(self.model, str):
                 self.model = serialization.deserialize(self.model)
 
-            def deserialize_reporters(reporters):
+            self.agent_reporters = self.agent_reporters
-                for (k, v) in reporters.items():
+            self.model_reporters = self.model_reporters
-                    if isinstance(v, str) and v.startswith("py:"):
+            self.tables = self.tables
-                        reporters[k] = serialization.deserialize(v.split(":", 1)[1])
-                return reporters
-
-            self.agent_reporters = deserialize_reporters(self.agent_reporters)
-            self.model_reporters = deserialize_reporters(self.model_reporters)
-            self.tables = deserialize_reporters(self.tables)
             self.id = f"{self.name}_{current_time()}"
 
     def run(self, **kwargs):
@@ -142,15 +132,6 @@ class Simulation:
         if kwargs:
             return replace(self, **kwargs).run()
 
-        self.logger.debug(
-            dedent(
-                """
-        Simulation:
-        ---
-        """
-            )
-            + self.to_yaml()
-        )
         param_combinations = self._collect_params(**kwargs)
         if _AVOID_RUNNING:
             _QUEUED.extend((self, param) for param in param_combinations)
@@ -244,7 +225,6 @@ class Simulation:
             id=iteration_id,
             seed=f"{self.seed}_iteration_{iteration_id}",
             dir_path=self.dir_path,
-            interval=self.interval,
             logger=self.logger.getChild(iteration_id),
             agent_reporters=agent_reporters,
             model_reporters=model_reporters,
@@ -359,8 +339,11 @@ def iter_from_py(pyfile, module_name='imported_file', **kwargs):
         for sim in _iter_queued():
             sims.append(sim)
         if not sims:
-            for (_name, sim) in inspect.getmembers(module, lambda x: inspect.isclass(x) and issubclass(x, Simulation)):
+            for (_name, env) in inspect.getmembers(module,
-                sims.append(sim(**kwargs))
+                                                   lambda x: inspect.isclass(x) and
+                                                   issubclass(x, environment.Environment) and
+                                                   (getattr(x, "__module__", None) != environment.__name__)):
+                sims.append(Simulation(model=env, **kwargs))
         del sys.modules[module_name]
     assert not _AVOID_RUNNING
     if not sims:

soil/time.py

@@ -1,7 +1,9 @@
 from mesa.time import BaseScheduler
 from queue import Empty
 from heapq import heappush, heappop, heapreplace
+from collections import deque
 import math
+import logging
 
 from inspect import getsource
 from numbers import Number
@@ -13,119 +15,54 @@ from mesa import Agent as MesaAgent
 
 INFINITY = float("inf")
 
+class Delay:
+    """A delay object which can be used both as a return value and as an awaitable (in async code)."""
+    __slots__ = ("delta", )
+    def __init__(self, delta):
+        self.delta = float(delta)
+
+    def __float__(self):
+        return self.delta
+    
+    def __await__(self):
+        return (yield self.delta)
+
 
 class DeadAgent(Exception):
     pass
 
 
-class When:
+class PQueueActivation(BaseScheduler):
-    def __init__(self, time):
+    """
-        if isinstance(time, When):
+    A scheduler which activates each agent with a delay returned by the agent's step method.
-            return time
+    If no delay is returned, a default of 1 is used.
-        self._time = time
     
-    def abs(self, time):
-        return self._time
-
-    def schedule_next(self, time, delta, first=False):
-        return (self._time, None)
-
-
-NEVER = When(INFINITY)
-
-
-class Delta(When):
-    def __init__(self, delta):
-        self._delta = delta
-
-    def abs(self, time):
-        return self._time + self._delta
-
-    def __eq__(self, other):
-        if isinstance(other, Delta):
-            return self._delta == other._delta
-        return False
-
-    def schedule_next(self, time, delta, first=False):
-        return (time + self._delta, None)
-
-    def __repr__(self):
-        return str(f"Delta({self._delta})")
-
-
-class BaseCond:
-    def __init__(self, msg=None, delta=None, eager=False):
-        self._msg = msg
-        self._delta = delta
-        self.eager = eager
-
-    def schedule_next(self, time, delta, first=False):
-        if first and self.eager:
-            return (time, self)
-        if self._delta:
-            delta = self._delta
-        return (time + delta, self)
-
-    def return_value(self, agent):
-        return None
-
-    def __repr__(self):
-        return self._msg or self.__class__.__name__
-
-
-class Cond(BaseCond):
-    def __init__(self, func, *args, **kwargs):
-        self._func = func
-        super().__init__(*args, **kwargs)
-
-    def ready(self, agent, time):
-        return self._func(agent)
-
-    def __repr__(self):
-        if self._msg:
-            return self._msg
-        return str(f'Cond("{dedent(getsource(self._func)).strip()}")')
-
-
-class TimedActivation(BaseScheduler):
-    """A scheduler which activates each agent when the agent requests.
     In each activation, each agent will update its 'next_time'.
     """
 
     def __init__(self, *args, shuffle=True, **kwargs):
         super().__init__(*args, **kwargs)
-        self._next = {}
         self._queue = []
         self._shuffle = shuffle
-        # self.step_interval = getattr(self.model, "interval", 1)
-        self.step_interval = self.model.interval
         self.logger = getattr(self.model, "logger", logger).getChild(f"time_{ self.model }")
         self.next_time = self.time
 
     def add(self, agent: MesaAgent, when=None):
         if when is None:
             when = self.time
-        elif isinstance(when, When):
+        else:
-            when = when.abs()
+            when = float(when)
 
         self._schedule(agent, None, when)
         super().add(agent)
 
-    def _schedule(self, agent, condition=None, when=None, replace=False):
+    def _schedule(self, agent, when=None, replace=False):
-        if condition:
+        if when is None:
-            if not when:
+            when = self.time
-                when, condition = condition.schedule_next(
-                    when or self.time, self.step_interval
-                )
-        else:
-            if when is None:
-                when = self.time + self.step_interval
-            condition = None
         if self._shuffle:
-            key = (when, self.model.random.random(), condition)
+            key = (when, self.model.random.random())
         else:
-            key = (when, agent.unique_id, condition)
+            key = (when, agent.unique_id)
-        self._next[agent.unique_id] = key
         if replace:
             heapreplace(self._queue, (key, agent))
         else:
@@ -137,70 +74,104 @@ class TimedActivation(BaseScheduler):
         an agent will signal when it wants to be scheduled next.
         """
 
-        self.logger.debug(f"Simulation step {self.time}")
+        if self.time == INFINITY:
-        if not self.model.running or self.time == INFINITY:
             return
 
-        self.logger.debug(f"Queue length: %s", len(self._queue))
+        next_time = INFINITY
+
+        now = self.time
 
         while self._queue:
-            ((when, _id, cond), agent) = self._queue[0]
+            ((when, _id), agent) = self._queue[0]
-            if when > self.time:
+            if when > now:
+                next_time = when
                 break
 
-            if cond:
-                if not cond.ready(agent, self.time):
-                    self._schedule(agent, cond, replace=True)
-                    continue
-                try:
-                    agent._last_return = cond.return_value(agent)
-                except Exception as ex:
-                    agent._last_except = ex
-            else:
-                agent._last_return = None
-                agent._last_except = None
-
-            self.logger.debug("Stepping agent %s", agent)
-            self._next.pop(agent.unique_id, None)
-
             try:
-                returned = agent.step()
+                when = agent.step() or 1
+                when += now
             except DeadAgent:
-                agent.alive = False
                 heappop(self._queue)
                 continue
 
-            # Check status for MESA agents
+            if when == INFINITY:
-            if not getattr(agent, "alive", True):
                 heappop(self._queue)
                 continue
 
-            if returned:
+            self._schedule(agent, when, replace=True)
-                next_check = returned.schedule_next(
-                    self.time, self.step_interval, first=True
-                )
-                self._schedule(agent, when=next_check[0], condition=next_check[1], replace=True)
-            else:
-                next_check = (self.time + self.step_interval, None)
-
-                self._schedule(agent, replace=True)
 
         self.steps += 1
 
-        if not self._queue:
+        self.time = next_time
+
+        if next_time == INFINITY:
             self.model.running = False
             self.time = INFINITY
             return
 
-        next_time = self._queue[0][0][0]
 
-        if next_time < self.time:
+class TimedActivation(BaseScheduler):
-            raise Exception(
+    def __init__(self, *args, shuffle=True, **kwargs):
-                f"An agent has been scheduled for a time in the past, there is probably an error ({when} < {self.time})"
+        super().__init__(*args, **kwargs)
-            )
+        self._queue = deque()
-        self.logger.debug("Updating time step: %s -> %s ", self.time, next_time)
+        self._shuffle = shuffle
+        self.logger = getattr(self.model, "logger", logger).getChild(f"time_{ self.model }")
+        self.next_time = self.time
 
-        self.time = next_time
+    def add(self, agent: MesaAgent, when=None):
+        if when is None:
+            when = self.time
+        else:
+            when = float(when)
+        self._schedule(agent, None, when)
+        super().add(agent)
+
+    def _schedule(self, agent, when=None, replace=False):
+        when = when or self.time
+        pos = len(self._queue)
+        for (ix, l) in enumerate(self._queue):
+            if l[0] == when:
+                l[1].append(agent)
+                return
+            if l[0] > when:
+                pos = ix
+                break
+        self._queue.insert(pos, (when, [agent]))
+
+    def step(self) -> None:
+        """
+        Executes agents in order, one at a time. After each step,
+        an agent will signal when it wants to be scheduled next.
+        """
+        if not self._queue:
+            return
+
+        now = self.time
+
+        next_time = self._queue[0][0]
+
+        if next_time > now:
+            self.time = next_time
+            return
+
+        bucket = self._queue.popleft()[1]
+        if self._shuffle:
+            self.model.random.shuffle(bucket)
+        for agent in bucket:
+            try:
+                when = agent.step() or 1
+                when += now
+            except DeadAgent:
+                continue
+
+            if when != INFINITY:
+                self._schedule(agent, when, replace=True)
+
+        self.steps += 1
+        if self._queue:
+            self.time = self._queue[0][0]
+        else:
+            self.time = INFINITY
 
 
 class ShuffledTimedActivation(TimedActivation):
@@ -211,3 +182,5 @@ class ShuffledTimedActivation(TimedActivation):
 class OrderedTimedActivation(TimedActivation):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, shuffle=False, **kwargs)
+
+

tests/test_agents.py

@@ -17,7 +17,7 @@ class TestAgents(TestCase):
         """The last step of a dead agent should return time.INFINITY"""
         d = Dead(unique_id=0, model=environment.Environment())
         ret = d.step()
-        assert ret == stime.NEVER
+        assert ret == stime.INFINITY
 
     def test_die_raises_exception(self):
         """A dead agent should raise an exception if it is stepped after death"""
@@ -52,23 +52,25 @@ class TestAgents(TestCase):
 
     def test_state_decorator(self):
         class MyAgent(agents.FSM):
-            run = 0
+            times_run = 0
 
             @agents.state("original", default=True)
             def root(self):
-                self.run += 1
                 return self.other
 
             @agents.state
             def other(self):
-                self.run += 1
+                self.times_run += 1
 
         e = environment.Environment()
         a = e.add_agent(MyAgent)
         e.step()
-        assert a.run == 1
+        assert a.times_run == 0
         a.step()
-        print("DONE")
+        assert a.times_run == 1
+        assert a.state_id == MyAgent.other.id
+        a.step()
+        assert a.times_run == 2
 
     def test_broadcast(self):
         """
@@ -86,7 +88,7 @@ class TestAgents(TestCase):
                 except Exception as ex:
                     print(ex)
                 while True:
-                    self.check_messages()
+                    self.process_messages()
                     yield
 
             def on_receive(self, msg, sender=None):
@@ -132,14 +134,14 @@ class TestAgents(TestCase):
                 while True:
                     if pongs or not pings:  # First agent, or anyone after that
                         pings.append(self.now)
-                        response = yield target.ask("PING")
+                        response = yield from target.ask("PING")
                         responses.append(response)
                     else:
                         print("NOT sending ping")
                     print("Checking msgs")
                     # Do not block if we have already received a PING
-                    if not self.check_messages():
+                    if not self.process_messages():
-                        yield self.received()
+                        yield from self.received()
                 print("done")
 
             def on_receive(self, msg, sender=None):
@@ -175,3 +177,199 @@ class TestAgents(TestCase):
         assert ev[0].unique_id == 1
         null = list(e.agents(unique_ids=[0, 1], agent_class=agents.NetworkAgent))
         assert not null
+
+    def test_agent_return(self):
+        '''
+        An agent should be able to cycle through different states and control when it
+        should be awaken.
+        '''
+        class TestAgent(agents.Agent):
+            @agents.state(default=True)
+            def one(self):
+                return self.two
+            
+            @agents.state
+            def two(self):
+                return self.three.at(10)
+            
+            @agents.state
+            def three(self):
+                return self.four.delay(1)
+
+            @agents.state
+            def four(self):
+                yield self.delay(2)
+                return self.five.delay(3)
+            
+            @agents.state
+            def five(self):
+                return self.delay(1)
+
+        model = environment.Environment()
+        a = model.add_agent(TestAgent)
+        assert a.state_id == TestAgent.one.id
+        assert a.now == 0
+        model.step()
+        assert a.state_id == TestAgent.two.id
+        assert a.now == 1
+        model.step()
+        assert a.state_id == TestAgent.three.id
+        assert a.now == 10
+        model.step()
+        assert a.state_id == TestAgent.four.id
+        assert a.now == 11
+        model.step()
+        assert a.state_id == TestAgent.four.id
+        assert a.now == 13
+        model.step()
+        assert a.state_id == TestAgent.five.id
+        assert a.now == 16
+        model.step()
+        assert a.state_id == TestAgent.five.id
+        assert a.now == 17
+
+    def test_agent_async(self):
+        '''
+        Async functions should also be valid states.
+        '''
+
+        class TestAgent(agents.Agent):
+            @agents.state(default=True)
+            def one(self):
+                return self.two
+            
+            @agents.state
+            def two(self):
+                return self.three.at(10)
+            
+            @agents.state
+            def three(self):
+                return self.four.delay(1)
+
+            @agents.state
+            async def four(self):
+                await self.delay(2)
+                return self.five.delay(3)
+            
+            @agents.state
+            def five(self):
+                return self.delay(1)
+            
+        model = environment.Environment()
+        a = model.add_agent(TestAgent)
+        assert a.now == 0
+        assert a.state_id == TestAgent.one.id
+        model.step()
+        assert a.now == 1
+        assert a.state_id == TestAgent.two.id
+        model.step()
+        assert a.now == 10
+        assert a.state_id == TestAgent.three.id
+        model.step()
+        assert a.state_id == TestAgent.four.id
+        assert a.now == 11
+        model.step()
+        assert a.state_id == TestAgent.four.id
+        assert a.now == 13
+        model.step()
+        assert a.state_id == TestAgent.five.id
+        assert a.now == 16
+        model.step()
+        assert a.state_id == TestAgent.five.id
+        assert a.now == 17
+
+    def test_agent_return_step(self):
+        '''
+        The same result as the previous test should be achievable by manually
+        handling the agent state.
+        '''
+        class TestAgent(agents.Agent):
+            my_state = 1
+            my_count = 0
+
+            def step(self):
+                if self.my_state == 1:
+                    self.my_state = 2
+                    return None
+                elif self.my_state == 2:
+                    self.my_state = 3
+                    return self.at(10)
+                elif self.my_state == 3:
+                    self.my_state = 4
+                    self.my_count = 0
+                    return self.delay(1)
+                elif self.my_state == 4:
+                    self.my_count += 1
+                    if self.my_count == 1:
+                        return self.delay(2)
+                    self.my_state = 5
+                    return self.delay(3)
+                elif self.my_state == 5:
+                    return self.delay(1)
+
+        model = environment.Environment()
+        a = model.add_agent(TestAgent)
+        assert a.my_state == 1
+        assert a.now == 0
+        model.step()
+        assert a.now == 1
+        assert a.my_state == 2
+        model.step()
+        assert a.now == 10
+        assert a.my_state == 3
+        model.step()
+        assert a.now == 11
+        assert a.my_state == 4
+        model.step()
+        assert a.now == 13
+        assert a.my_state == 4
+        model.step()
+        assert a.now == 16
+        assert a.my_state == 5
+        model.step()
+        assert a.now == 17
+        assert a.my_state == 5
+
+    def test_agent_return_step_async(self):
+        '''
+        The same result as the previous test should be achievable by manually
+        handling the agent state.
+        '''
+        class TestAgent(agents.Agent):
+            my_state = 1
+
+            async def step(self):
+                self.my_state = 2
+                await self.delay()
+                self.my_state = 3
+                await self.at(10)
+                self.my_state = 4
+                await self.delay(1)
+                await self.delay(2)
+                self.my_state = 5
+                await self.delay(3)
+                while True:
+                    await self.delay(1)
+
+        model = environment.Environment()
+        a = model.add_agent(TestAgent)
+        assert a.my_state == 1
+        assert a.now == 0
+        model.step()
+        assert a.now == 1
+        assert a.my_state == 2
+        model.step()
+        assert a.now == 10
+        assert a.my_state == 3
+        model.step()
+        assert a.now == 11
+        assert a.my_state == 4
+        model.step()
+        assert a.now == 13
+        assert a.my_state == 4
+        model.step()
+        assert a.now == 16
+        assert a.my_state == 5
+        model.step()
+        assert a.now == 17
+        assert a.my_state == 5

tests/test_config.py

@@ -29,15 +29,12 @@ class TestConfig(TestCase):
     def test_torvalds_config(self):
         sim = simulation.from_config(os.path.join(ROOT, "test_config.yml"))
         MAX_STEPS = 10
-        INTERVAL = 2
-        assert sim.interval == INTERVAL
         assert sim.max_steps == MAX_STEPS
         envs = sim.run()
         assert len(envs) == 1
         env = envs[0]
-        assert env.interval == 2
         assert env.count_agents() == 3
-        assert env.now == INTERVAL * MAX_STEPS 
+        assert env.now == MAX_STEPS 
 
 
 def make_example_test(path, cfg):

tests/test_config.yml

@@ -2,4 +2,3 @@
 source_file: "../examples/torvalds_sim.py"
 model: "TorvaldsEnv"
 max_steps: 10
-interval: 2

tests/test_exporters.py

@@ -88,7 +88,7 @@ class Exporters(TestCase):
             parameters=dict(
                 network_generator="complete_graph",
                 network_params={"n": n_nodes},
-                agent_class="CounterModel",
+                agent_class=agents.CounterModel,
                 agent_reporters={"times": "times"},
             ),
             max_time=max_time,

tests/test_main.py

@@ -7,8 +7,6 @@ from functools import partial
 
 from os.path import join
 from soil import simulation, Environment, agents, network, serialization, utils, config, from_file
-from soil.time import Delta
-
 from mesa import Agent as MesaAgent
 
 ROOT = os.path.abspath(os.path.dirname(__file__))
@@ -114,7 +112,6 @@ class TestMain(TestCase):
     def test_serialize_class(self):
         ser, name = serialization.serialize(agents.BaseAgent, known_modules=[])
         assert name == "soil.agents.BaseAgent"
-        assert ser == agents.BaseAgent
 
         ser, name = serialization.serialize(
             agents.BaseAgent,
@@ -123,11 +120,9 @@ class TestMain(TestCase):
             ],
         )
         assert name == "BaseAgent"
-        assert ser == agents.BaseAgent
 
         ser, name = serialization.serialize(CustomAgent)
         assert name == "test_main.CustomAgent"
-        assert ser == CustomAgent
         pickle.dumps(ser)
 
     def test_serialize_builtin_types(self):
@@ -168,7 +163,6 @@ class TestMain(TestCase):
 
     def test_fsm(self):
         """Basic state change"""
-
         class ToggleAgent(agents.FSM):
             @agents.default_state
             @agents.state
@@ -193,7 +187,7 @@ class TestMain(TestCase):
             @agents.default_state
             @agents.state
             def ping(self):
-                return self.pong, 2
+                return self.pong.delay(2)
 
             @agents.state
             def pong(self):
@@ -203,7 +197,7 @@ class TestMain(TestCase):
         when = a.step()
         assert when == 2
         when = a.step()
-        assert when == Delta(a.interval)
+        assert when == None
 
     def test_load_sim(self):
         """Make sure at least one of the examples can be loaded"""

tests/test_time.py

@@ -4,26 +4,6 @@ from soil import time, agents, environment
 
 
 class TestMain(TestCase):
-    def test_cond(self):
-        """
-        A condition should match a When if the concition is True
-        """
-
-        t = time.Cond(lambda t: True)
-        f = time.Cond(lambda t: False)
-        for i in range(10):
-            w = time.When(i)
-            assert w == t
-            assert w is not f
-
-    def test_cond(self):
-        """
-        Comparing a Cond to a Delta should always return False
-        """
-
-        c = time.Cond(lambda t: False)
-        d = time.Delta(1)
-        assert c is not d
 
     def test_cond_env(self):
         """ """
@@ -36,11 +16,12 @@ class TestMain(TestCase):
 
         class CondAgent(agents.BaseAgent):
             def step(self):
-                nonlocal done
+                nonlocal done, times_started, times_asleep, times_awakened
                 times_started.append(self.now)
                 while True:
                     times_asleep.append(self.now)
-                    yield time.Cond(lambda agent: agent.now >= 10, delta=2)
+                    while self.now < 10:
+                        yield self.delay(2)
                     times_awakened.append(self.now)
                     if self.now >= 10:
                         break
@@ -57,7 +38,6 @@ class TestMain(TestCase):
         assert times_started == [0]
         assert times_awakened == [10]
         assert done == [10]
-        # The first time will produce the Cond.
         assert env.schedule.steps == 6
         assert len(times) == 6
 
@@ -65,11 +45,10 @@ class TestMain(TestCase):
             times.append(env.now)
             env.step()
 
-        assert times == [0, 2, 4, 6, 8, 10, 11]
+        assert times == [0, 2, 4, 6, 8, 10, 11, 12]
         assert env.schedule.time == 13
-        assert times_started == [0, 11]
+        assert times_started == [0, 11, 12]
-        assert times_awakened == [10]
+        assert times_awakened == [10, 11, 12]
-        assert done == [10]
+        assert done == [10, 11, 12]
-        # Once more to yield the cond, another one to continue
+        assert env.schedule.steps == 8
-        assert env.schedule.steps == 7
+        assert len(times) == 8
-        assert len(times) == 7