Fix die bug

First iteration to achieve MESA compatibility.
As a side effect, we have removed `simpy`.

For a full list of changes, see `CHANGELOG.md`.

CHANGELOG.md

@@ -3,10 +3,13 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [0.20.1]
+### Fixed
+* Agents would run another step after dying.
+## [0.20.0]
 ### Added
 * Integration with MESA
-* `not_agent_ids` paramter to get sql in history
+* `not_agent_ids` parameter to get sql in history
 ### Changed
 * `soil.Environment` now also inherits from `mesa.Model`
 * `soil.Agent` now also inherits from `mesa.Agent`
@@ -16,11 +19,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Removed
 * `simpy` dependency and compatibility. Each agent used to be a simpy generator, but that made debugging and error handling more complex. That has been replaced by a scheduler within the `soil.Environment` class, similar to how `mesa` does it.
 * `soil.history` is now a separate package named `tsih`. The keys namedtuple uses `dict_id` instead of `agent_id`.
-
 ### Added
 * An option to choose whether a database should be used for history 
-
-
 ## [0.15.2]
 ### Fixed
 * Pass the right known_modules and parameters to stats discovery in simulation

examples/random_delays/random_delays.py

@@ -0,0 +1,45 @@
+'''
+Example of setting a 
+Example of a fully programmatic simulation, without definition files.
+'''
+from soil import Simulation, agents
+from soil.time import Delta
+from random import expovariate
+import logging
+
+
+
+class MyAgent(agents.FSM):
+    '''
+    An agent that first does a ping
+    '''
+
+    defaults = {'pong_counts': 2}
+
+    @agents.default_state
+    @agents.state
+    def ping(self):
+        self.info('Ping')
+        return self.pong, Delta(expovariate(1/16))
+
+    @agents.state
+    def pong(self):
+        self.info('Pong')
+        self.pong_counts -= 1
+        self.info(str(self.pong_counts))
+        if self.pong_counts < 1:
+            return self.die()
+        return None, Delta(expovariate(1/16))
+
+
+s = Simulation(name='Programmatic',
+               network_agents=[{'agent_type': MyAgent, 'id': 0}],
+               topology={'nodes': [{'id': 0}], 'links': []},
+               num_trials=1,
+               max_time=100,
+               agent_type=MyAgent,
+               dry_run=True)
+
+
+logging.basicConfig(level=logging.INFO)
+envs = s.run()

soil/VERSION

@@ -1 +1 @@
-0.20.0
+0.20.1

soil/agents/__init__.py

@@ -20,6 +20,10 @@ def as_node(agent):
 
 IGNORED_FIELDS = ('model', 'logger')
 
+
+class DeadAgent(Exception):
+    pass
+
 class BaseAgent(Agent):
     """
     A special Agent that keeps track of its state history.
@@ -129,13 +133,14 @@ class BaseAgent(Agent):
             return None
 
     def die(self, remove=False):
+        self.info(f'agent {self.unique_id}  is dying')
         self.alive = False
         if remove:
             self.remove_node(self.id)
 
     def step(self):
         if not self.alive:
-            return time.When('inf')
+            raise DeadAgent(self.unique_id)
         return super().step() or time.Delta(self.interval)
 
     def log(self, message, *args, level=logging.INFO, **kwargs):
@@ -300,7 +305,10 @@ class FSM(NetworkAgent, metaclass=MetaFSM):
 
     def step(self):
         self.debug(f'Agent {self.unique_id} @ state {self.state_id}')
-        interval = super().step()
+        try:
+            interval = super().step()
+        except DeadAgent:
+            return time.When('inf')
         if 'id' not in self.state:
             # if 'id' in self.state:
             #     self.set_state(self.state['id'])