AssocOp::AssignOp(op) => format!("{} {}= {}", lhs, token_to_string(&token::BinOp(op)), rhs),
AssocOp::As => format!("{} as {}", lhs, rhs),
AssocOp::DotDot => format!("{}..{}", lhs, rhs),
AssocOp::AssignOp(op) => format!("{} {}= {}", lhs, token_to_string(&token::BinOp(op)), rhs),
AssocOp::As => format!("{} as {}", lhs, rhs),
AssocOp::DotDot => format!("{}..{}", lhs, rhs),