README.md

COCODE 🐔

Simple assembly-like language, which can be used to program CPython directly:

from cocode import CodeObjectProxy, Constant, Return, Add

code_proxy = CodeObjectProxy(
  Constant("Hello "),  # push constant "Hello " onto value stack
  Constant("world!"),  # push constant "world!" onto value stack
  Add(),               # Push summ of last two onto stack
  Return()             # Terminate frame and return top of the stack to the caller
)

code = code_proxy.assemble()
assert eval(code) == "Hello world!"

As you can see, cocode doesn't introduce any additional complexity:

>>> import dis
>>> dis.dis(code)
  0           0 LOAD_CONST               0 ('Hello ')
              3 LOAD_CONST               1 ('world!')
              6 BINARY_ADD
              7 RETURN_VALUE

WARNING:

cocode actually generates low level code object from your assembly code, so any awkward movement leads to segfault into CPython internals. So this is your responsibility to write correct algorithm, no additional checks performed. Tested on Python 3.4 and 3.5, known to fail on 3.6.

EXAMPLE: factorial function:

def factorial_asm(value):
    pass


factorial_asm_proxy = CodeObjectProxy(
    VariableFast("value"),
    Dup(),
    Label(Constant(1), "loop"),
    Sub(),
    Dup(),
    Rot3(),
    Mult(),
    Rot2(),
    Dup(),
    Constant(1),
    Compare("=="),
    PopJumpFalse("loop"),
    Pop(),
    Return(),
    interface=factorial_asm,
)

fac_asm_code = factorial_asm_proxy.assemble()
factorial_asm.__code__ = fac_asm_code

Then you may use it as always

assert factorial_asm(10) == 3628800

EXAMPLE: fibonacci generator:

def fibonacci(a, b):
    pass

fib_asm_code = CodeObjectProxy(
    VariableFast('a'),
    VariableFast('b'),
    Label(Dup(), "loop"),
    Rot3(),
    Add(),
    Dup(),
    Yield(),
    Pop(),
    Jump("loop"),
    interface=fibonacci,
)

# so, the algorithm is
# a,b -> a,b,b -> b,a,b -> b,a+b -> b,a+b,a+b -> yield a+b and loop back

fib_code = fib_asm_code.assemble(code_flags=99)  # make me generator
fibonacci.__code__ = fib_code

iterator = fibonacci(1, 1)

>>> print(next(iterator))
2
>>> print(next(iterator))
3
>>> print(next(iterator))
5

Even though this code runs faster then

def fib(a, b):
    while 1:
        a,b = b,a+b
        yield b

it seems that most of the time interpreter spends at YIELD_VALUE instruction.