CSC223 2004F, Class 13: Project Management with Ant

Admin:
* www.cs.grinnell.edu seems to be down
  * file:///home/rebelsky/Web/Courses/CS223/2004F/EBoards/ant.txt
  * file:///home/rebelsky/Web/Courses/CS223/2004F/Outlines/current.html
* Why attend convo
  * Grinnellians have no common intellectual heritage
* Fun with prospies
  * Why come to Grinnell rather than top-ranked engineering school
    * Nice small classes and collaborative envrionment
  * Why come to Grinnell rather than other schools?
    * We won't let you take as much Math and CS
    * Great place to explore options: Open curriculum, "Take whatever you want"
  * Why come to Grinnell rather than Knox?
    * We're rich, they're poor.
  * Why come to Grinnell rather than UofC?
    * Open curriculum vs. carefully-designed core curriclum
    * Small town USA vs. "ten bookstores in a five block radius"
    * More drinking here (by those of legal age) (at least compared to when I was an undergraduate)
* Danger, it's Friday, the 13th class!
* Homework due.  How much time?  From 9 to 40 person-hours.
* Homework assigned.  Discussed during class.
* ACM Programming competition forthcoming: Jesse and Mark
* Who knows Swing, the primary GUI toolkit for Java?
  * Not many, covered week after next
* Next week: XP (read the book)
* How to read a book:
  * Carefully
  * Thoughtfully/Reflectively
  * Repeatedly (not for this class)

Overview:
* Homework, part 1: Representing World State
* Homework, part 2: Implementing Bugs
* Philosophy of Ant
* Ant basics
* Ant Variables

/HW4, part 1: Representing the State of the World/

* "The state of the world": Associate a collection of objects with each x,y coordinate.
* Implementation strategies:
  + Two-dimensional array: O(1) to find stuff at a position
  + Vector of vectors
  + List of location,contents pairs
  + Tree of area,contents pairs: O(log_n) time to find stuff at a position; If the grid is "sparsely" populated, may give more efficient storage
  + Hashtable of contents indexed by location
* Design an implementation-independent interface, WorldState
  + addThingAt
  + listThingsAt
  + removeThingAt
* Implement it in each of the five ways mentioned above.
* Summarize the benefits and costs of each implementation.

	FOUR SKIPPERS
	Jesse,Mark,Chase

/HW4, part 2: Implementing NotVerySmartSleepyAsexuallyReproducingAlienBugs/

* We are going to implement bugs as nondeterministic finite state machines
  * Finite state machine: A bug has a current state ("looking for food"; "running away from a BugEater"; "bringing food back to colony") and a way of deciding what to do based on state and environment.
  * Nondeterministic: More than one choice may be available in a particular state (given that there are many things happening in the environment)
* The finite state machine is stored in a text file.  Format
	STATE,INPUT,NEWSTATE,OPTIONAL-ACTION
* Should states be strings or integers?
  * Strings: Readability; Easier for novices  <--- da winner for the file
  * Integers: Faster (input, output, compare, store)
* Actions:
	move(direction) - n,s,e,w,ne,nw,sw,se [1 time unit]
	run(direction) - moves two spaces, uses more energy [1 time unit]
	sleep [10 time units]
	eat - eats one unit of whatever it has in hand [1 time unit]
	pickup - pick up up to ten units of food (ten units if at least ten units in the current location, less otherwise) [1 time unit]
	drop - drops all of the food in hand [1 time unit]
	breed - generates a new bug [5 time units]
	secrete(type) - leave a pheremone at the current spot [0 time units]
	attack(direction) - attack another bug
WANDERING,FOOD,GOHOME,PICKUP
WANDERING,EATER(N),PANIC-SOUTH-0,SECRETE(WARNING)
PANIC-SOUTH-0,*,PANIC-SOUTH-1,RUN(S)
PANIC-SOUTH-1,*,PANIC-SOUTH-2,RUN(S)
PANIC-SOUTH-2,*,WANDERING,RUN(S)
GOHOME,P5(S),GOHOME,MOVE(S)

	Sam,Merrick,Luis
	Gene,Omondi,Margaret