(program, labels) = assemble("""
:init
SET 0 <- 0
SET 1 <- 1
SET 2 <- 2
SET 3 <- 1
:start
MUL 2 3 -> 4 5 6
SUB 4 1 -> 4
ADD 5 1 -> 5
DIV 4 5 -> 11
DIV 11 2 -> 11
SUB 13 11 -> 13
SUB 3 1 -> 10
BRZ finish
ADD 2 7 -> 7
DIV 6 7 -> 11
MUL DATA 11 -> 12
ADD 12 13 -> 13
SUB 10 1 -> 10
BRZ finish
:loop
SUB 6 1 -> 6
ADD 1 7 -> 7
DIV 6 7 -> 8
MUL 8 11 -> 11
SUB 6 1 -> 6
ADD 1 7 -> 7
DIV 6 7 -> 9
MUL 9 11 -> 11
MUL DATA 11 -> 12
ADD 12 13 -> 13
SUB 10 1 -> 10
BRN loop
:finish
SUB 0 13
PRINT
ADD 1 3 -> 3
SET 7 <- 0
SET 13 <- 0
HALT
""")
# https://enigmaticcode.wordpress.com/2015/10/21/running-the-first-program-part-3/
# Program 6 - factorial3.py
from analytical_engine import AnalyticalEngine, Column, assemble
import sys
n = (40 if len(sys.argv) < 2 else int(sys.argv[1]))
(program, _) = assemble("""
:init
SET 0 <- {n}
SET 1 <- 1
SET 2 <- 1
:loop
# operation 1: v[2] *= v[0]
MUL 0 2 -> 2
# operation 2: v[2] -= 1
SUB 0 1 -> 0
# branch if non-zero to operation 1
BRN loop
# end
HALT
""".format(n=n))
# initialise the engine
p = AnalyticalEngine(vars=3, number=Column(digits=50), trace=1)
# load the program to compute factorial(n)
p.load_program(program)
# run the program