int main () {
// example expression: (true and x) or (y and (not x))
BooleanExp* expression;
Context context;
VariableExp* x = new VariableExp("X");
VariableExp* y = new VariableExp("Y");
expression = new OrExp(new AndExp(new Constant(true), x), new AndExp(y, new NotExp(x)));
context.Assign(x, false);
context.Assign(y, true);
bool result = expression->Evaluate(context);
VariableExp* z = new VariableExp("Z");
NotExp not_z(z);
BooleanExp* replacement = expression->Replace("Y", not_z);
context.Assign(z, true);
result = replacement->Evaluate(context);
return 0;
}
main () {
/*
*/
BooleanExp* expression;
Context context;
VariableExp* x = new VariableExp("X");
VariableExp* y = new VariableExp("Y");
expression = new OrExp(
new AndExp(new Constant(true), x),
new AndExp(y, new NotExp(x))
);
/*
*/
context.Assign(x, false);
context.Assign(y, true);
bool result = expression->Evaluate(context);
/*
*/
BooleanExp* replacement;
VariableExp* z = new VariableExp("Z");
replacement = new NotExp(z);
expression->Replace("Y", *replacement);
context.Assign(z, true);
result = expression ->Evaluate(context);
/*
*/
}
int main()
{
BooleanExp* expression,*expression2;
Context context;
VariableExp* x = new VariableExp("X");
VariableExp* y = new VariableExp("Y");
expression = new OrExp(
new AndExp(new Constant(true), x),
new AndExp(y, new NotExp(x)));
context.Assign(x, false);
context.Assign(y, true);
bool result = expression->Evaluate(context);
cout<<"result: "<<result<<endl;
}
int main(int argc, char* argv[])
{
//生成表达式
AbstractExpression* expression;
//解析器对象
Context context;
//两个变量
VariableExp* varX = new VariableExp("keyX");
VariableExp* varY = new VariableExp("keyY");
/*一个复杂表达式 或（与（常量，变量），与（变量，非（变量）））*/
expression = new OrExp(
new AndExp(new ConstantExp(true), varX),
new AndExp(varY, new NotExp(varX)));
//在解析器中建立外部名字和值的关联
context.Assign(varX, false);
context.Assign(varY, true);
//递归运算表达式求值
bool result = expression->Interpret(context);
cout<<"result: "<<result<<endl;
printf("Hello World!\n");
return 0;
}
int main(int argc, char ** argv)
{
BooleanExp *expression;
Context context;
VariableExp* x = new VariableExp("X");
VariableExp* y = new VariableExp("Y");
expression = new OrExp(
new AndExp(new Constant(true),x),
new AndExp(y,new NotExp(x)));
context.Assign(x,false);
context.Assign(y,true);
bool result = expression->Evaluate(context);
char *str;
if(result == true)
str = "true";
else
str = "false";
printf("result is %s\n",str);
system("pause");
return 0;
}
