GRUN for Antlr4:如何使用? [英] GRUN for Antlr4: How to use?

问题描述

对于语法:

grammar qwe;询问: 列运算符值 EOF;柱子: [a-z_]+;操作员: ('='|'>'|'<');标量: [a-z_]+;价值: 标量;WS : [ \t\r\n]+ ->跳过 ;

COLUMN 和 SCALAR 有相同的规则.

从项目 learning_antlr4 级别运行:

grun qwe tokens -tokens qwe/qwe.tokens

输出为空.

我做错了什么?别名保存在哪里?

解决方案

假设您已经设置了 grun 别名(如果没有，请参阅本页顶部的 QuickStart https://www.antlr.org):

您想要的是查看由 Lexer 处理您的输入生成的令牌流(而不是您的 qwe.tokens 文件)

qwe.txt:

total_sales>qwe

ANTLR on  master [✘+?]➜ antlr4 qwe.g4ANTLR on  master [✘+?]➜ javac *.javaANTLR on  master [✘+?]➜ grun qwe 令牌 -tokens ,1:0][@1,11:11='>',<操作员>,1:11][@2,12:14='qwe',,1:12][@3,15:14='<EOF>',<EOF>,1:15]

正如你所看到的...... total_sales 和 qwe 都被识别为 COLUMN 令牌，

For grammar:

grammar qwe;

query
    : COLUMN OPERATOR value EOF
    ;

COLUMN
    : [a-z_]+
    ;

OPERATOR
    : ('='|'>'|'<')
    ;

SCALAR
    : [a-z_]+
    ;

value
    : SCALAR
    ;

WS : [ \t\r\n]+ -> skip ;

there are identical rules COLUMN and SCALAR. Here I was advised to use grun aliases.

I installed it for my Ubuntu. And for folders structure:

ran this from project learning_antlr4 level:

grun qwe tokens -tokens < qwe/qwe.tokens

The output was empty.

What do I wrong? Where that aliases are saved?

解决方案

Assuming you have the grun alias set up (if not, see the QuickStart at the tops of this page https://www.antlr.org):

What you want is to view the token stream produced by the Lexer processing your input (not your qwe.tokens file)

qwe.txt:

total_sales>qwe

ANTLR on  master [✘+?] 
➜ antlr4 qwe.g4      

ANTLR on  master [✘+?] 
➜ javac *.java

ANTLR on  master [✘+?] 
➜ grun qwe tokens -tokens < qwe.txt
[@0,0:10='total_sales',<COLUMN>,1:0]
[@1,11:11='>',<OPERATOR>,1:11]
[@2,12:14='qwe',<COLUMN>,1:12]
[@3,15:14='<EOF>',<EOF>,1:15]

AS you can see... both total_sales and qwe are recognized as COLUMN tokens,

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