Brainfuck解析器(Python)

global cs
global ip

global ss
#global sp

global ds
global bp

global tab
global out

cs='++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>.'
ip = 0

ss = []
#sp = 0

ds = []
bp = 0

tab = 0
out = []

def tab_():
    i = tab
    stab = ''
    while i > 0:
        stab += '\t'
        i -= 1
    return stab

def push(var):
    global ss
    ss.append(var)

def pop():
    global ss
    return ss.pop()

def op_inc_val():
    global ip
    count = 0
    while True:
        op = cs[ip]            
        ip = ip + 1
        if op == '+':
            count = count + 1
        else:
            break
    l = len(ds)
    if l <= bp:
        ds.append(0)
    old = ds[bp]
    old += count
    ds[bp] = old
    print tab_()+'ds[%d] += %d                  (%d)'%(bp, count, old)

def op_dec_val():
    global ip    
    count = 0
    while True:
        op = cs[ip]            
        ip = ip + 1
        if op == '-':
            count = count + 1
        else:
            break
    old = ds[bp]
    old -= count
    ds[bp] = old
    print tab_()+'ds[%d] -= %d                  (%d)'%(bp, count, old)

def op_inc_dp():
    global bp
    bp = bp + 1

def op_dec_dp():
    global bp
    bp = bp - 1

def op_jmp_fwd():
    global tab
    global ip
    print tab_()+'while ds[%d]=%d:'%(bp, ds[bp])
    tab=tab + 1
    if ds[bp] != 0:
        curip = ip - 1
        push(curip)
    else:
        c = 1; 
        while c > 0:
            op = cs[ip]
            if op == '[':
                c += 1
            elif op == ']':
                c -= 1
            ip += 1

def op_jmp_bck():
    global tab
    global ip
    tab = tab - 1
    if ds[bp] != 0:
        ip = pop()

def op_out():
    print tab_()+'putchar(ds[%d])                  (%d)'%(bp, ds[bp])
    out.append(ds[bp])

def op_in():
    print tab_()+'getchar'

end = len(cs)
while ip < end:
    op = cs[ip]
    ip = ip + 1
    if op == '+':
        ip = ip - 1
        op_inc_val()
        ip = ip - 1
    elif op == '-':
        ip = ip - 1
        op_dec_val()
        ip = ip - 1
    elif op == '>':
        op_inc_dp()
    elif op == '<':
        op_dec_dp()
    elif op == '[':
        op_jmp_fwd()
    elif op == ']':
        op_jmp_bck()
    elif op == '.':
        op_out()
    elif op == ',':
        op_in()
    else:
        print 'invalid opcode'
        break
    
print out
str = ''
for c in out:
    str += '%c'%(c)
print str