
        # preprocess the input
input = input.upper()
input = input.strip()

# initialize the program counter
pc = 0

# initilize the stack
stack = []

# initilize the depth levels
depth = [({}, 0)]

# find the labels and methods
labels = {}
methods = {}
currIndex = 0
for line in input.split("\n"):
    # look in the line for method headers and labels
    m1 = re.match("\s*(\w+)\s+(\d+)\s+(\d+)\s*", line)
    m2 = re.match("\s*\W*(\w+)\W*\s*", line)
    
    # branch for methods, then labels
    if m1:
        arg = m1.groups()
        methods[arg[0]] = (currIndex, arg[1], arg[2])
    elif m2:
        labels[m2.groups()[0]] = currIndex
    
    # update the index
    currIndex += 1
        
# error flag
error = False

# stop executing error = True # grab the top two values a = stack.pop() b = stack.pop() # add them and put the result on the stack stack.append(b + a) # grab the top two values a = stack.pop() b = stack.pop() # add them and put the result on the stack stack.append(b - a) # grab the top two values a = stack.pop() b = stack.pop() # add them and put the result on the stack stack.append(b & a) # grab the top two values a = stack.pop() b = stack.pop() # add them and put the result on the stack stack.append(b | a) # grab the top value a = stack.pop() # put it on the stack twice stack.append(a) stack.append(a) # remove the top value stack.pop() # grab the top two values a = stack.pop() b = stack.pop() # put them back on in the opposite order stack.append(a) stack.append(b) # grab the index from the depth stack l, index = depth.pop() # this is not necessary # ask the user for input # TODO: implement this # output the top value on the stack output += str(stack.pop()) # add a line break output += "\n" # add the value to the stack stack.append(int(arg[0])) # grab the top value a = stack.pop() # if it's less than 0, branch if a < 0: # loop up the label if labels.has_key(arg[0]): index = labels[arg[0]] # don't have that label else: error = True output = "Label '" + arg[0] + "' could not be found (in IFLT)." # grab the top value a = stack.pop() # if it's equal to 0, branch if a == 0: # loop up the label if labels.has_key(arg[0]): index = labels[arg[0]] # don't have that label else: error = True output = "Label '" + arg[0] + "' could not be found (in IFEQ)." # grab the top two values a = stack.pop() b = stack.pop() # if they're equal, branch if a == b: # loop up the label if labels.has_key(arg[0]): index = labels[arg[0]] # don't have that label else: error = True output = "Label '" + arg[0] + "' could not be found (in IF_ICMPEQ)." # loop up the label if labels.has_key(arg[0]): index = labels[arg[0]] # don't have that label else: error = True output = "Label '" + arg[0] + "' could not be found (in GOTO)." # load a local variable if depth[len(depth) - 1][0].has_key(arg[0]): a = depth[len(depth) - 1][0][arg[0]] stack.append(a) # the variable has not yet been set else: error = True output = "Local variable " + arg[0] + " has not been set (for ILOAD)." # store the variable depth[len(depth) - 1][0][arg[0]] = stack.pop() # increment a local variable if depth[len(depth) - 1][0].has_key(arg[0]): depth[len(depth) - 1][0][arg[0]] = depth[len(depth) - 1][0][arg[0]] + int(arg[1]) # the variable has not yet been set else: error = True output = "Local variable " + arg[0] + " has not been set (for IINC)." # look up the method header if methods.has_key(arg[0]): # build the new local variables l = {} # store the original index (plus 1) si = index # build the local variables index, fromStack, otherLocal = methods[arg[0]] for i in range(int(fromStack)): l[str(int(fromStack) - i - 1)] = stack.pop() for i in range(int(fromStack), int(otherLocal)): l[str(i)] = 0 # store it depth.append((l, si)) # no method found with that name else: error = True output = "Method '" + arg[0] + "' could not be found (in INVOKEVIRTUAL)." # no constant pool is defined, cannot load one error = True output = "The constant pool is not defined (in LDC_W."