I am using Java. I need to parse the following line using regex :
<actions>::=<action><action>|X|<game>|alpha
It should give me tokens <action>, <action>,X and <game>
What kind of regex will work?
I was trying sth like: "<[a-zA-Z]>" but that doesn't take care of X or alpha.
You can try something like this:
String str="<actions>::=<action><action>|X|<game>|alpha";
str=str.split("=")[1];
Pattern pattern = Pattern.compile("<.*?>|\\|.*?\\|");
Matcher matcher = pattern.matcher(str);
while (matcher.find()) {
System.out.println(matcher.group());
}
You should have something like this:
String input = "<actions>::=<action><action>|X|<game>|alpha";
Matcher matcher = Pattern.compile("(<[^>]+>)(<[^>]+>)\\|([^|]+)\\|(<[^|]+>)").matcher(input);
while (matcher.find()) {
System.out.println(matcher.group().replaceAll("\\|", ""));
}
You didn't specefied if you want to return alpha or not, in this case, it doesn't return it.
You can return alpha by adding |\\w* to the end of the regex I wrote.
This will return:
<action><action>X<game>
From the original pattern it is not clear if you mean that literally there are <> in the pattern or not, i'll go with that assumption.
String pattern="<actions>::=<(.*?)><(.+?)>\|(.+)\|<(.*?)\|alpha";
For the java code you can use Pattern and Matcher: here is the basic idea:
Pattern p = Pattern.compile(pattern, Pattern.DOTALL|Pattern.MULTILINE);
Matcher m = p.matcher(text);
m.find();
for (int g = 1; g <= m.groupCount(); g++) {
// use your four groups here..
}
You can use following Java regex:
Pattern pattern = Pattern.compile
("::=(<[^>]+>)(<[^>]+>)\\|([^|]+)\\|(<[^>]+>)\\|(\\w+)$");
alphaor not?