View source for NARG GP stacks code

Linked from [[NARG]].

Code by [[User:obscurite]] for Brad's GP workshop. This code generates random "programs". This will be further modified to produce programs with desired traits and then to have them evolve. Written for python 3.0.

<pre>

from random import choice
from random import randint

programList = []           # hold program elements (ints and operations)
opStack = []               # temporarily hold operations as we handle them
intStack = []              # hold ints as we handle them
ops = ['add', 'mul']       # all possible operations


########################################################################
# Stack stuff
def popOp():               # pop operation from op stack
  return opStack.pop()

def pushOp(op):            # push operation onto op stack
  opStack.append(op)

def popProg():             # pop thing from programList
  return programList.pop()

def pushProg(stuff):       # push thing onto programList
  programList.append(stuff)

def popInt():              # pop int from int stack
  return intStack.pop()

def pushInt(stuff):        # push int onto int stack
  intStack.append(stuff)

#####
# Random stuff
def randOp():              # return a random choice of op (add/mul)
  return choice(ops)

def randNum():             # return a random int from 1-10
  return randint(0, 10)

def randThing():           # return a random int or random op randomly
  if randint(0, 1):
    return randNum()
  else:
    return randOp()

########################################################################
# main function

def main():

  numthings = 100 # num of things to generate

  # build up a random list of things (ops and ints)
  for i in range(1, numthings):
    pushProg(randThing())      # push a random thing into programList

  # Show what's in the full programList
  print("PROGRAM LIST:")
  print(programList)

  # For every thing in programList, handle it appropriately
  for i in range(1, numthings):
    thing = popProg()
    if isinstance(thing, int): # it's a number, push it to number stack!
      pushInt(thing)
    else:                      # it's an op, do something with numbers!
      if len(intStack) > 1:    # we have at least two ints on num stack
        if (thing == 'mul'):
          pushInt(popInt() * popInt())   # do the mul operation and push
        else:
          pushInt(popInt() + popInt())   # do the add operation and push

  # Show what's left in our op and int stacks
  print("OP STACK:")
  print(opStack)
  print("INT STACK:")
  print(intStack)


########################################################################
# run the program!
main();

</pre>