scan.lex

请在解压时看说明文档 内有详细说明

%{
#include <stdio.h>
#include <string.h>
#define PROGRAM 1
#define BEGIN	2
#define END     3
#define CONST   4
#define SEMI    5 /* ; */
#define WORD    6
#define BOOLEAN 7
#define TRUE    8
#define FALSE   9
#define INT     10
#define REAL    11
#define ARRAY   12
#define LF      13 /* [ */
#define RF      14 /* ] */ 
#define COMA    15 /* , */
#define ASSIGN  16 /* := */
#define IF      17 
#define THEN    18
#define ELSE    19
#define WHILE   20
#define DO      21
#define REPEAT  22
#define UNTIL   23
#define FOR     24
#define TO      25
#define READ    26
#define WRITE   27
#define OPER    28  /* +,-,*,etc */
#define LOGIC   34  /* and , or ,not */ 
#define MATH    37  /* < ,<=, etc*/
#define ICON    43  /* intconst */
#define FCON    44  /* floatconst*/
#define MAOHAO	45  /* : */
#define LB		46  /* ( */
#define RB		47  /* ) */
void output(int cate,char *content);
%}
digit [0-9]+
float [+-]?[0-9]*\.[0-9]+ 
word  [a-zA-Z][a-zA-Z0-9]*
logic and|or|not
math  >|>=|=|<>|<|<=
oper  [+|-|*|/]

%%
program {output(PROGRAM,yytext);}
begin {output(BEGIN,yytext);}
end {output(END,yytext);}
const {output(CONST,yytext);}
";" {output(SEMI,yytext);}
boolean {output(BOOLEAN,yytext);}
true {output(TRUE,yytext);}
false {output(FALSE,yytext);}
int {output(INT,yytext);}
real {output(REAL,yytext);}
array {output(ARRAY,yytext);}
"[" {output(LF,yytext);}
"]" {output(RF,yytext);}
"," {output(COMA,yytext);}
":=" {output(ASSIGN,yytext);}
"(" {output(LB,yytext);}
")" {output(RB,yytext);}
if {output(IF,yytext);}
then {output(THEN,yytext);}
else {output(ELSE,yytext);}
while {output(WHILE,yytext);}
do {output(DO,yytext);}
repeat {output(REPEAT,yytext);}
until {output(UNTIL,yytext);}
for {output(FOR,yytext);}
to {output(TO,yytext);}
read {output(READ,yytext);}
write {output(WRITE,yytext);}
{oper} {output(OPER,yytext);}
{math} {output(MATH,yytext);}
{logic} {output(LOGIC,yytext);}
{digit} {output(ICON,yytext);}
{float} {output(FCON,yytext);}
{word} {output(WORD,yytext);}
":" {output(MAOHAO,yytext);}
[ \t\n] ;

%%
void output(int cate,char *content)
{
	switch(cate)
	{
		case 1:fprintf(yyout,"(PROGRAM,%s)\n",content);break;
		case 2:fprintf(yyout,"(BEGIN,%s)\n",content);break;
		case 3:fprintf(yyout,"(END,%s)\n",content);break;
		case 4:fprintf(yyout,"(CONST,%s)\n",content);break;
		case 5:fprintf(yyout,"(SEMI,%s)\n",content);break;
		case 6:fprintf(yyout,"(WORD,%s)\n",content);break;
		case 7:fprintf(yyout,"(BOOLEAN,%s)\n",content);break;
		case 8:fprintf(yyout,"(TRUE,%s)\n",content);break;
		case 9:fprintf(yyout,"(FALSE,%s)\n",content);break;
		case 10:fprintf(yyout,"(INT,%s)\n",content);break;
		case 11:fprintf(yyout,"(REAL,%s)\n",content);break;
		case 12:fprintf(yyout,"(ARRAY,%s)\n",content);break;
		case 13:fprintf(yyout,"(LF,%s)\n",content);break;
		case 14:fprintf(yyout,"(RF,%s)\n",content);break;
		case 15:fprintf(yyout,"(COMA,%s)\n",content);break;
		case 16:fprintf(yyout,"(ASSIGN,%s)\n",content);break;
		case 17:fprintf(yyout,"(IF,%s)\n",content);break;
		case 18:fprintf(yyout,"(THEN,%s)\n",content);break;
		case 19:fprintf(yyout,"(ELSE,%s)\n",content);break;
		case 20:fprintf(yyout,"(WHILE,%s)\n",content);break;
		case 21:fprintf(yyout,"(DO,%s)/n",content);break;
		case 22:fprintf(yyout,"(REPEAT,%s)\n",content);break;
		case 23:fprintf(yyout,"(UNTIL,%s)\n",content);break;
		case 24:fprintf(yyout,"(FOR,%s)\n",content);break;
		case 25:fprintf(yyout,"(TO,%s)\n",content);break;
		case 26:fprintf(yyout,"(READ,%s)\n",content);break;
		case 27:fprintf(yyout,"(WRITE,%s)\n",content);break;
		case 28:fprintf(yyout,"(OPER,%s)\n",content);break;
		case 34:fprintf(yyout,"(LOGIC,%s)\n",content);break;
		case 37:fprintf(yyout,"(MATH,%s)\n",content);break;
		case 43:fprintf(yyout,"(ICON,%s)\n",content);break;
		case 44:fprintf(yyout,"(FCON,%s)\n",content);break;
		case 45:fprintf(yyout,"(MAOHAO,%s)\n",content);break;
		case 46:fprintf(yyout,"(LB,%s)\n",content);break;
		case 47:fprintf(yyout,"(RB,%s)\n",content);break;
		default:break;
	}
}
int main(int argc,char ** argv)
{
	argc--;argv++;
	if(argc > 0)
	{
	if((yyin = fopen(argv[0],"r")) == NULL)
	{
		printf("%s can not be opened",argv[0]);
		return 0;
	}
	}
	else
	{
		yyin = stdin;
	}	

	yyout = fopen("result.txt","w");
	yylex();
	return 1;

}