ANTLR4 Parser，未创建访问者 [英] ANTLR4 Parser, Visitor not created

问题描述

我是ANTLR的新手，并尝试在ANTLR4中编写语法，而不需要事先刷过以前的版本。我正在阅读 The Definitive ANTLR 4 Reference 一书。我使用Eclipse并安装了此处中给出的ANTLR4 IDE。我在Expr.g4中写了以下语法：

I'm new to ANTLR and trying to write grammar in ANTLR4 without any prior brush with the previous version. I'm following the book 'The Definitive ANTLR 4 Reference'. I use Eclipse and installed ANTLR4 IDE as given in here. I wrote the following grammar in Expr.g4:

grammar Expr;

import Common;

options{
language = Java;
}
prog: stat+;

stat: expr NEWLINE
    | ID '=' expr NEWLINE
    | NEWLINE;

expr: expr ('/'|'*') expr
    | expr ('+'|'-') expr
    | INT
    | ID
    | '('expr')';

Common.g4包含以下内容：

The Common.g4 contains the following:

lexer grammar Common;

ID: [A-Za-z]+;
INT: [0-9]+;
NEWLINE: '\r'?'\n';
WS: [\t]+ -> skip;

创建了lexer.java，但没有创建parser.java和visitor.java以及其他基本文件。请帮我解决问题。在此先感谢。

The lexer.java was created but not parser.java and visitor.java and other base file. Please help me fix the problem. Thanks in advance.

推荐答案

事实上我曾经遇到过同样的问题，我曾经在同一个项目中整合了两个G4文件第一个生成访问者，但第二个没有。

In fact I had the same problem once, I used to integrate two G4 files within the same project the first one generated Visitor but the second didn't.

然后我意识到每个G4文件都有自己的代码生成配置，您可以通过以下方式更改：

Then I realized that each G4 file has its own configuration for code generation that you can change by:

1. 右键单击G4文件，然后运行方式


2. 选择外部工具配置


3. 将无访客更改为访客 ，你可以为
   听众做同样的事。

1. Right click on the G4 file then Run As
2. Choose External tool configuration
3. Change the no-visitor to visitor, you can do the same for listener.

现在访客生成文件。

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