替换ANTLR中的令牌 [英] Replace token in ANTLR
本文介绍了替换ANTLR中的令牌的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想使用ANTLR替换令牌.
I want to replace a token using ANTLR.
我尝试使用TokenRewriteStream并替换,但是没有用.
I tried with TokenRewriteStream and replace, but it didn't work.
有什么建议吗?
ANTLRStringStream in = new ANTLRStringStream(source);
MyLexer lexer = new MyLexer(in);
TokenRewriteStream tokens = new TokenRewriteStream(lexer);
for(Object obj : tokens.getTokens()) {
CommonToken token = (CommonToken)obj;
tokens.replace(token, "replacement");
}
词法分析器会找到所有出现的单行注释,我也想在原始来源中替换它们.
The lexer finds all occurences of single-line comments, and i want to replace them in the original source too.
这是语法:
grammar ANTLRTest;
options {
language = Java;
}
@header {
package main;
}
@lexer::header {
package main;
}
rule: SingleLineComment+;
SingleLineComment
: '//' ~( '\r' | '\n' )* {setText("replacement");}
;
我要说的是替换文件中的所有单行注释.
What i want to do is replace all single-line comments in a file, let's say.
推荐答案
重写词法分析器中的文本:
Rewrite the text inside the lexer:
SingleLineComment
: '//' ~('\r' | '\n')* {setText("replacement");}
;
编辑
好的,这是一个快速演示,您可以如何从一种语言中过滤某些标记:
EDIT
Okay, here's a quick demo how you can filter certain tokens from a language:
grammar SingleCommentStrip;
parse returns [String str]
@init{StringBuilder builder = new StringBuilder();}
: (t=. {builder.append($t.text);})* EOF {$str = builder.toString();}
;
SingleLineComment
: '//' ~('\r' | '\n')* {skip();}
;
MultiLineComment
: '/*' .* '*/'
;
StringLiteral
: '"' ('\\' . | ~('"' | '\\' | '\r' | '\n'))* '"'
;
AnyOtherChar
: .
;
Main.java
import org.antlr.runtime.*;
public class Main {
public static void main(String[] args) throws Exception {
SingleCommentStripLexer lexer = new SingleCommentStripLexer(new ANTLRFileStream("Test.java"));
SingleCommentStripParser parser = new SingleCommentStripParser(new CommonTokenStream(lexer));
String adjusted = parser.parse();
System.out.println(adjusted);
}
}
Test.java
// COMMENT
class Test {
/*
// don't remove
*/
// COMMENT AS WELL
String s = "/* don't // remove */ \" \\ me */ as well";
}
现在运行演示:
java -cp antlr-3.3.jar org.antlr.Tool SingleCommentStrip.g
javac -cp antlr-3.3.jar *.java
java -cp .:antlr-3.3.jar Main
将打印:
class Test {
/*
// don't remove
*/
String s = "/* don't // remove */ \" \\ me */ as well";
}
(即删除单行注释)
这篇关于替换ANTLR中的令牌的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
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