I know,we can define some conditions in lex, matching：
1.<DIRECTIVE>{STRING} {printf("Matching the DIRECTIVE state!");}
2.<REFERENCE>{INTEGER} {printf("Matching the REFERNCE state!");}
3.[\n] {printf("Matching the INITIAL state?");}
4.<*>{DOBULE} {printf("Matching all state include INITIAL? Seem not!");}
How to use the states in the right way? What is the difference in conditions on line 3 and 4?
The whole .l file, cut by me,now it just to realize a reference.When I run it,it can work well,but it always says "line:4: error: syntax error" at last,I don't why! My test.vm has only 2 lines text.
%{
/**支持了所有的token,不支持转义和多行注释*/
#include<stdio.h>
#include<string.h>
#include "context.h"
#include "bool.h"
#include "vtl4.tab.h"
extern int yylex();
/**bracket标志*/
int bracket_flag = 0;
/**引用标志*/
int ref_flag = 0;
/**多行注释标记*/
int mul_comment_flag = 0;
%}
%option stack
%option noyywrap yylineno
%x REF
VAR_NAME ([_a-zA-Z]+[a-zA-Z0-9_\-]*)
%%
/**这里去除$#\n防止覆盖状态REF和DIRECTIVE*/
[^$\n#]*? {printf("text:%s\n",yytext);yylval.string = yytext; return CONTENT;}
/**换行单独取出来，还没清楚为什么*/
\n {printf("newLine:%s\n",yytext);yylval.string = yytext; return CONTENT;}
/**添加^$防止只匹配最后一个变量
例如：<p class="$b">$a $b</p> 只匹配了最后一个$b
*/
[^#$]*?/"$" {BEGIN REF;printf("begin ref text:%s\n",yytext);yylval.string = yytext; return CONTENT;}
<REF>"$"|"$!"/"{"?{VAR_NAME} {ref_flag++;printf("$:%s\n",yytext);return DOLLAR;}
<REF>"{" {printf("{:%s\n",yytext);return BRACE;}
<DIRECTIVE>"}" {printf("}:%s\n",yytext);return BRACE_CLOSE;}
<REF>{VAR_NAME}/[^0-9A-Za-z_\-] {
printf("ref name:%s\n",yytext);
ref_flag--;
yylval.sym = find_symbol(yytext);
return ID;
}
<REF>[ /t"="\n] {BEGIN INITIAL; printf("ref end:%s\n",yytext);}
<REF>[}] {printf("}:%s\n",yytext);return BRACE_CLOSE;}
<<EOF>> {printf("lex end:%s\n",yytext);return LEX_EOF;}
%%
The whole .y file:
%{
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "bool.h"
#include "parser.h"
#include "context.h"
#include "vtl4.tab.h"
extern FILE * yyin;
extern FILE * yyout;
int yylex();
#define YYDEBUG 1
%}
/*priority level*/
%union {
struct simpleNode *ast;
double d;
int i;
bool b;
char* string;
struct symbol *sym;
}
%token ADD SUB MUL DIV MOD EQUAL PARENTHESIS CLOSE_PARENTHESIS BRACE BRACE_CLOSE LOGICAL_AND LOGICAL_OR LOGIC_EQUAL LOGICAL_LT LOGICAL_LE LOGICAL_GT LOGICAL_GE LOGICAL_NOT_EQUALS
%token LEX_EOF
%token <string> CONTENT STRING_LITERAL SINGLE_LINE_COMMENT MULTI_LINE_COMMENT
%token <b> BOOL
%token INTEGER_LITERAL
%token <d> DOUBLE_LITERAL
%token DOLLAR
%token <sym> ID
%token HASH SET PARSE IF ELSE ELSEIF FOREACH IN END
%type <ast> root statements statement reference content
%start root
%%
/*JJTPROCESS*/
root:statements LEX_EOF {printf("yacc root\n");$$ = process($1);}
;
statements
: statement {printf("yacc statements:statement\n"); $$ = $1; }
| statements statement {printf("yacc statements:statements statement\n"); $$ = add_ybrother($1,$2);}
;
statement
: reference {printf("yacc statement:ref\n"); $$ = $1;}
| content
;
reference
: DOLLAR ID {printf("yacc ref\n");$$ = reference($2);}
;
content
: CONTENT {$$ = text(NULL);}
;
%%
int main(){
printf("BEGIN:\n");
FILE *src;
src = fopen("test.vm","r");
yyin = src;
int result = yyparse();
fclose(src);
return result;
}
