赋值语句的翻译，递归下降法是语法分析中最易懂的一种方法。它的主要原理是，对每个非终极符按其产生式结构构造相应语法分析子程序，其中终极符产生匹配命令，而非终极符则产生过程调用命令。-Translation of assignment statements, recursive descent parser is the most straightforward method. Its main principle is that their production structures constructed the ultimate symbol corresponding to each non-parsing routines, which produces the ultimate symbol matching command, rather than the ultimate symbol generated procedure call commands.