heyong.fu
89 lines
2.6 KiB
Python
89 lines
2.6 KiB
Python
class SimpleVM:
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# 初始化方法
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def __init__(self):
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self.stack = []
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self.locals = {}
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self.globls = {}
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def load_const(self, const):
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# 将常量推到栈中
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self.stack.append(const)
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print(f"加载常量: {const} -> 栈: {self.stack}")
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def store_name(self, name):
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if not self.stack:
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raise RuntimeError("栈为空")
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# 取出值
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value = self.stack.pop()
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# 存储到字典中
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self.locals[name] = value
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print(f"存储变量: {name} = {value}")
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def load_name(self, name):
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if name in self.locals:
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value = self.locals[name]
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elif name in self.globls:
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value = self.globls[name]
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else:
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raise RecursionError(f"name:{name} is not defined")
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self.stack.append(value)
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print(f"加载变量: {name} = {value} -> 栈: {self.stack}")
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def binary_add(self):
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if len(self.stack) < 2:
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raise RecursionError("栈中元素不足")
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#
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a = self.stack.pop()
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b = self.stack.pop()
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result = a + b
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self.stack.append(result)
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print(f"加法: {a} + {b} = {result} -> 栈: {self.stack}")
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def return_value(self):
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if not self.stack:
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return None
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value = self.stack.pop()
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print(f"返回: {value}")
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return value
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def vm_execution():
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vm = SimpleVM()
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# 输出即将执行的代码说明
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print("执行代码: a = 10; b = 20; c = a + b")
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# 构造指令序列
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instructions = [
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("LOAD_CONST", 10), # 加载常量10
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("STORE_NAME", "a"), # 存储到变量a
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("LOAD_CONST", 20), # 加载常量20
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("STORE_NAME", "b"), # 存储到变量b
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("LOAD_NAME", "a"), # 加载变量a
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("LOAD_NAME", "b"), # 加载变量b
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("BINARY_ADD",), # 执行加法
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("STORE_NAME", "c"), # 存储到变量c
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("LOAD_NAME", "c"), # 加载变量c
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("RETURN_VALUE",), # 返回值
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]
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for instruction in instructions:
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# 获取操作嘛
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op = instruction[0]
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# 获取操作参数
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args = instruction[1:] if len(instruction) > 1 else []
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# 判断不同指令，来调用不同的方法
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if op == "LOAD_CONST":
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vm.load_const(args[0])
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elif op == "STORE_NAME":
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vm.store_name(args[0])
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elif op == "LOAD_NAME":
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vm.load_name(args[0])
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elif op == "BINARY_ADD":
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vm.binary_add()
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elif op == "RETURN_VALUE":
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result = vm.return_value()
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print(f"最终打印结果c={result}")
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vm_execution()
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