Construction-of-Compilers/Uebung-01/MaMa.py

from typing import Dict, Optional, Tuple, List

class MaMa:
    def __init__(self, prog: Dict[int, str] | List[str], stack: Dict[int, int] | List[int] | None = None) -> None:
        # Execution state
        self.steps = 0

        # Allow either dict or list for program input
        if isinstance(prog, list):
            self.prog = {i: instr for i, instr in enumerate(prog)}
        else:
            self.prog = prog

        # Program counter
        self.p_prog = 0

        # Stack memory and pointer
        self.stack: Dict[int, int] = {}
        self.p_stack = -1
        self.initial_stack: Dict[int, int] = {}
        if stack is not None:
            self.reload(stack)

        # Machine halted flag
        self.halted = False


    # Restore initial machine state
    def reload(self, stack: Dict[int, int] | List[int] | None = None) -> None:
        if stack is None:
            self.stack = dict(self.initial_stack)
        else:
            if isinstance(stack, list):
                self.stack.update({i: v for i, v in enumerate(stack)})
            else:
                self.stack.update(stack)

        self.p_prog = 0
        self.p_stack = max(self.stack.keys(), default=-1)
        self.halted = False
        self.steps = 0

    def run(self, max_steps: int = 1000) -> List[Dict[str, int|str|dict]]:
        steps = 0
        journal = [self.config('init')]
        while not self.halted and steps < max_steps:
            journal.append(self.step())
            steps += 1
        return journal

    def is_halted(self) -> bool:
        return self.halted

    def step(self) -> Dict[str, int|str|dict]:
        if self.halted or self.p_prog not in self.prog:
            self.halted = True
            return self.config("halted")

        call = self.prog[self.p_prog]
        name, arg = self.decode(call)
        method = getattr(self, f"_{name}", None)
        if method is None:
            raise ValueError(f"Unknown instruction: {call}")

        method(arg)
        self.steps += 1
        return self.config(call)

    def config(self, call: str) -> Dict[str, int|str|dict]:
        return {
            "step": self.steps,
            "call": call,
            "p_prog": self.p_prog,
            "p_stack": self.p_stack,
            "stack": dict(self.stack),
        }

    @staticmethod
    def decode(call: str) -> Tuple[str, Optional[int]]:
        if "(" in call:
            name, arg = call.split("(")
            return name, int(arg[:-1])
        return call, None

    # Stop execution
    def _stop(self, _: Optional[int]) -> None:
        self.halted = True

    # Remove top element from stack
    def _pop(self, _: Optional[int]) -> None:
        self.p_stack -= 1
        self.p_prog += 1

    # Load stack pointer value onto stack
    def _ldsp(self, _: Optional[int]) -> None:
        self.p_stack += 1
        self.stack[self.p_stack] = self.p_stack
        self.p_prog += 1

    # Push constant n onto stack
    def _push(self, n: Optional[int]) -> None:
        assert n is not None
        self.p_stack += 1
        self.stack[self.p_stack] = n
        self.p_prog += 1

    # Add top two stack elements
    def _add(self, _: Optional[int]) -> None:
        self.stack[self.p_stack - 1] += self.stack[self.p_stack]
        self.p_stack -= 1
        self.p_prog += 1

    # Subtract top element from second-top element
    def _sub(self, _: Optional[int]) -> None:
        self.stack[self.p_stack - 1] -= self.stack[self.p_stack]
        self.p_stack -= 1
        self.p_prog += 1

    # Multiply top two stack elements
    def _mult(self, _: Optional[int]) -> None:
        self.stack[self.p_stack - 1] *= self.stack[self.p_stack]
        self.p_stack -= 1
        self.p_prog += 1

    # Integer division of second-top by top stack element
    def _div(self, _: Optional[int]) -> None:
        self.stack[self.p_stack - 1] //= self.stack[self.p_stack]
        self.p_stack -= 1
        self.p_prog += 1

    # Load value from relative address n in stack
    def _ldo(self, n: Optional[int]) -> None:
        assert n is not None
        old_sp = self.p_stack
        self.p_stack += 1
        self.stack[self.p_stack] = self.stack[old_sp + n]
        self.p_prog += 1

    # Store top value to relative address n in stack
    def _sto(self, n: Optional[int]) -> None:
        assert n is not None
        self.stack[self.p_stack + n] = self.stack[self.p_stack]
        self.p_stack -= 1
        self.p_prog += 1

    # Unconditional jump to address a
    def _ujp(self, a: Optional[int]) -> None:
        assert a is not None
        self.p_prog = a

    # Conditional jump if top two elements are equal
    def _equal(self, a: Optional[int]) -> None:
        assert a is not None
        if self.stack[self.p_stack - 1] == self.stack[self.p_stack]:
            self.p_stack -= 2
            self.p_prog = a
        else:
            self.p_stack -= 2
            self.p_prog += 1

    # Conditional jump if second-top ≤ top element
    def _leq(self, a: Optional[int]) -> None:
        assert a is not None
        if self.stack[self.p_stack - 1] <= self.stack[self.p_stack]:
            self.p_stack -= 2
            self.p_prog = a
        else:
            self.p_stack -= 2
            self.p_prog += 1