Updated arg passing & demos

demos/MyModelArgs.rb

@@ -7,13 +7,13 @@ class MyModel
 
   def init
     @x = 1
-    schedule(:increment, rand(2), n: 1, c: 97)
+    schedule(:increment, rand(2), n: 1, char: 'z'.ord)
   end
 
-  def increment(n:, c:)
+  def increment(n:, char:)
     @x += n
-    schedule(:increment, 2.0 * rand(2), n: @x, c: c + 1)
-    printf "%f, %f, %c\n", model_time, @x, c
+    schedule(:increment, 2.0 * rand(2), n: @x, char: char - 1)
+    printf "%f, %f, %c\n", model_time, @x, char
     schedule(:halt, 0.0) if model_time > 10
   end
 end

demos/sptf.rb

+#!/usr/bin/env ruby
+
+require_relative '../lib/simplekit'
+require_relative '../lib/priority_queue'
+
+# Customer class to store arrival times and processing times.
+class Customer
+  attr_reader :arrival_time, :processing_time
+
+  def initialize(arrival, processing)
+    @arrival_time = arrival
+    @processing_time = processing
+  end
+
+  include Comparable
+  def <=>(other)
+    processing_time <=> other.processing_time
+  end
+end
+
+# Demonstration model of a shortest-processing-time-first queueing system.
+# There are k servers and both the arrival and service processes could
+# be anything.
+class SPTF
+  include SimpleKit
+
+  # Constructor - initializes the model parameters.
+  # param: arrivalRate - The rate at which customers arrive to the system.
+  # param: serviceRate - The rate at which individual servers serve.
+  # param: maxServers - The total number of servers in the system.
+  # param: closeTime - The time the server would like to shut down.
+  def initialize(arrivalRate, serviceRate, maxServers, closeTime)
+    @arrivalRate = arrivalRate
+    @serviceRate = serviceRate
+    @maxServers = maxServers
+    @closeTime = closeTime
+  end
+
+  # Initialize the model state and schedule any necessary events.
+  def init
+    @numAvailableServers = @maxServers
+    @q = PriorityQueue.new
+    schedule(:arrival, 0.0)
+  end
+
+
+  # An arrival event generates a customer and their associated service
+  # time, adds the customer to the queue, schedules the next arrival,
+  # and schedules a beginService event if a server is available.
+  def arrival
+    @q.push Customer.new(model_time, exponential(@serviceRate))
+    schedule(:arrival, exponential(@arrivalRate))
+    schedule(:beginService, 0.0) if (@numAvailableServers > 0)
+  end
+
+  # Start service for the first customer in line, removing that
+  # customer from the queue and utilizing one of the available
+  # servers.  An endService will be scheduled.  Report the current
+  # time and how long this customer spent in line.
+  def beginService
+    current_customer = @q.pop
+    @numAvailableServers -= 1
+    schedule(:endService, current_customer.processing_time)
+    printf "%f,%f\n", model_time, model_time - current_customer.arrival_time
+  end
+
+  # Frees up an available server, and schedules a beginService if
+  # anybody is waiting in line.  If the line is empty and it's after
+  # the desired closing time, halt the simulation.
+  def endService
+    @numAvailableServers += 1
+    if (@q.empty?)
+      halt if model_time >= @closeTime
+    else
+      schedule(:beginService, 0.0)
+    end
+  end
+
+  # Exponential random variate generator.
+  # param: rate - The rate (= 1 / mean) of the distribution.
+  # returns: A realization of the specified distribution.
+  def exponential(rate)
+    -Math.log(rand) / rate
+  end
+
+end
+
+# Instantiate an SPTF object with a particular parameterization and run it.
+SPTF.new(4.5, 1.0, 5, 100.0).run

lib/simplekit.rb

@@ -55,7 +55,7 @@ module SimpleKit
     #     at invocation time.
     def schedule(event, delay, **args)
       raise 'Model scheduled event with negative delay.' if delay < 0
-      @event_list.push EventNotice.new(event, @model_time, delay, args)
+      @event_list.push EventNotice.new(event, @model_time, delay, **args)
     end
 
     # Start execution of a model. The simulation +model_time+ is initialized
@@ -71,7 +71,7 @@ module SimpleKit
         if current_event.args.empty?
           @user_model.send(current_event.event)
         else
-          @user_model.send(current_event.event, current_event.args)
+          @user_model.send(current_event.event, **current_event.args)
         end
       end
     end
@@ -88,7 +88,7 @@ module SimpleKit
   private class EventNotice
     attr_reader :event, :time, :time_stamp, :args
 
-    def initialize(event, time, delay, **args)
+    def initialize(event, time, delay, args)
       @event = event
       @time_stamp = time
       @time = time + delay