public While(Expr condition, Stmt body)
{
Condition = condition;
Body = body;
}
public If(Expr condition, Stmt thenBranch, Stmt elseBranch)
{
Condition = condition;
Thenbranch = thenBranch;
Elsebranch = elseBranch;
}
private void Resolve(Stmt statement) => statement.Accept(this);
