Java 如何解决.flex文件的语法问题?
这是我第一次使用jflex,我在网上用我的母语(葡萄牙语)找到了一个教程,我安装并组装了所有东西 但是当我试图生成“Lexer”类时,它在我的“.flex”文件中显示了一个语法错误,我不知道可能会发生什么,因为看起来一切正常 .flex文件Java 如何解决.flex文件的语法问题?,java,lexical-analysis,jflex,Java,Lexical Analysis,Jflex,这是我第一次使用jflex,我在网上用我的母语(葡萄牙语)找到了一个教程,我安装并组装了所有东西 但是当我试图生成“Lexer”类时,它在我的“.flex”文件中显示了一个语法错误,我不知道可能会发生什么,因为看起来一切正常 .flex文件 //NOME_VARIAVEL,INT,DEC,COMENTARIO,BRANCO,PALAVRA_CHAVE,ERRO package Compilador; import static Compilador.Token.*; %% %{ priv
//NOME_VARIAVEL,INT,DEC,COMENTARIO,BRANCO,PALAVRA_CHAVE,ERRO
package Compilador;
import static Compilador.Token.*;
%%
%{
private void imprimir (String token,String lexema){
System.out.println(lexema +" ===>> " + token);
}
%}
%class Lexer
%type Token
nomeVariavel = [_a-zA-Z][_zA-z0-9]*
inteiro = [0-9]+
decimal = [0-9]+["."]+[0-9]+
blocoComentario = "/*" ~"*/"
branco = [\t|\n|\r]+
linhaComentario = [branco]*"//" .*
palavrasChave = "if" | "class" | "int" | "while" | "for" | "do" | "float"
%%
{palavrasChave} { imprimir("PALAVRA_CHAVE : ", yytext()); return PALAVRA_CHAVE; }
{nomeVariavel} { imprimir("VARIAVEL : ", yytext()); return NOME_VARIAVEL; }
{inteiro} { imprimir("NUMERO INTEIRO : ", yytext()); return INT; }
{decimal} { imprimir("NUMERO DECIMAL : ", yytext()); return DEC; }
{blocoComentario} { imprimir("COMENTARIO : ", yytext()); return COMENTARIO; }
{linhaComentario} { imprimir("COMENTARIO : ", yytext()); return COMENTARIO; }
{branco} ( return BRANCO; }
. {imprimir("<<< CARACTER INVALIDO!!! >>> ",yytext()); return ERROR;}
<<EOF>> {return null;}
package compilador;
import java.io.*;
public class GeraLexer {
public static void main(String[] args) throws IOException {
String arquivo ="<path redacted for reasons, but it is finding the file>";
geraLexer(arquivo);
}
public static void geraLexer(String arq){
File file = new File(arq);
jflex.Main.generate(file);
}
}
generator.flex文件
//NOME_VARIAVEL,INT,DEC,COMENTARIO,BRANCO,PALAVRA_CHAVE,ERRO
package Compilador;
import static Compilador.Token.*;
%%
%{
private void imprimir (String token,String lexema){
System.out.println(lexema +" ===>> " + token);
}
%}
%class Lexer
%type Token
nomeVariavel = [_a-zA-Z][_zA-z0-9]*
inteiro = [0-9]+
decimal = [0-9]+["."]+[0-9]+
blocoComentario = "/*" ~"*/"
branco = [\t|\n|\r]+
linhaComentario = [branco]*"//" .*
palavrasChave = "if" | "class" | "int" | "while" | "for" | "do" | "float"
%%
{palavrasChave} { imprimir("PALAVRA_CHAVE : ", yytext()); return PALAVRA_CHAVE; }
{nomeVariavel} { imprimir("VARIAVEL : ", yytext()); return NOME_VARIAVEL; }
{inteiro} { imprimir("NUMERO INTEIRO : ", yytext()); return INT; }
{decimal} { imprimir("NUMERO DECIMAL : ", yytext()); return DEC; }
{blocoComentario} { imprimir("COMENTARIO : ", yytext()); return COMENTARIO; }
{linhaComentario} { imprimir("COMENTARIO : ", yytext()); return COMENTARIO; }
{branco} ( return BRANCO; }
. {imprimir("<<< CARACTER INVALIDO!!! >>> ",yytext()); return ERROR;}
<<EOF>> {return null;}
package compilador;
import java.io.*;
public class GeraLexer {
public static void main(String[] args) throws IOException {
String arquivo ="<path redacted for reasons, but it is finding the file>";
geraLexer(arquivo);
}
public static void geraLexer(String arq){
File file = new File(arq);
jflex.Main.generate(file);
}
}
包编译器;
导入java.io.*;
公共类GeraLexer{
公共静态void main(字符串[]args)引发IOException{
字符串arquivo=“”;
geraLexer(arquivo);
}
公共静态虚化器(字符串arq){
文件=新文件(arq);
jflex.Main.generate(文件);
}
}
生成时出现错误
Reading "<path redacted for reasons, but it is finding the file>"
Error in file "<path redacted for reasons, but it is finding the file>" (line 28):
Syntax error.
. {imprimir("<<< CARACTER INVALIDO!!! >>> ",yytext()); return ERROR;}
^
Exception in thread "main" jflex.GeneratorException: Generation aborted
at jflex.Main.generate(Main.java:139)
at compilador.GeraLexer.geraLexer(GeraLexer.java:13)
at compilador.GeraLexer.main(GeraLexer.java:8)
Java Result: 1
CONSTRUÍDO COM SUCESSO (tempo total: 0 segundos)
正在读取“”
文件“”中出现错误(第28行):
语法错误。
. {imprimir(“>”,yytext());返回错误;}
^
线程“main”jflex.GeneratorException中出现异常:生成中止
在jflex.Main.generate(Main.java:139)
位于compileador.GeraLexer.GeraLexer(GeraLexer.java:13)
位于compileador.GeraLexer.main(GeraLexer.java:8)
Java结果:1
施工成功(总速度:0秒)
感谢任何愿意帮忙的人,是的,我先在谷歌上搜索过。在前一行中,你已经
{branco} ( return BRANCO; }
(
应该是{
您很快就会发现编写自己的解析器时,在正确的位置发现错误并不总是容易的。错误通常是在一个令牌之后检测到的,有时该令牌位于下一行。规则中还有许多其他错误。
[“]
中的引号和[\t\n\r]中的条形图
被视为普通字符,因此它们成为字符类的一部分。而[branco]
是一个字符类,它与这六个字符中的任何一个匹配;您希望宏扩展{branco}
.Dang,我没有注意到,谢谢你,伙计,这是一个教程遗漏的好信息,我一直在搜索它显示的行中的错误,并掩盖了上一行,现在它被解决了,谢谢=D。