语法分析

C2.1 实验目的

编制一个递归下降分析程序,实现对词法分析程序所提供的单词序列的语法检查和结构分析.

C2.2 实验要求

利用C语言编制递归下降分析程序,并对简单语言进行语法分析.

C2.2.1待分析的简单语言的语法

用扩充的BNF表示如下:

(1)<程序>：：＝begin<语句串>end

(2)<语句串>：：＝<语句>{ <语句>}

(3)<语句>：：＝<赋值语句>

(4)<赋值语句>：：＝ID：＝<表达式>

(5)<表达式>：：＝<项>｛＋<项> | —项>｝

(6)<项>：：＝<因子>{*<因子> | /<因子>}

(7)<因子>：：＝ID | NUM | (<表达式>)

Ｃ２。２。２实验要求说明

输入单词串，以“＃”结束，如果是文法正确的句子，则输出成功信息，打印“success”,否则输出“error”.

-Syntax analysis

The experiment was C2.1

Recursive analysis of a decline in the preparation of procedures, procedures for the realization of the lexical analysis provided by the grammar checker word sequence and structure analysis.

C2.2 Experimental requirements

The use of C language procedures for the preparation of analysis of recursive descent, and a simple analysis of language syntax.

C2.2.1 to be analyzed in a simple language syntax

With the expansion of the BNF as follows:

(1) <program>:: = begin <statement string> end

(2) <statement string >::=< statement> (　<statement>)

(3) <>::=< assignment statement>

(4) <assignment statement>:: = ID: = <expression>

(5) <>::=< expression of> (+ <item> |- item>)

(6) <>::=< factor of> (* <factor> |/<factor>)

(7) <factor>:: = ID | NUM | (<expression>)

C2. 2. 2 Experimental requested clarification

Enter t