Regular Expression question: how to enumerate all matches? - 未名空间MITBBS历史存档

国际科技财经博客移民网络热点娱乐民生时事公众号

Redian新闻

>未名空间

>Java - 爪哇娇娃

Regular Expression question: how to enumerate all matches?

Regular Expression question: how to enumerate all matches?# Java - 爪哇娇娃

G*a2009-05-26 07:05

1 楼

I want to obtain all the possible matches of "a" from "aaaaa", that should be:
a
aa
aaa
aaaa
aaaaa
but "a+" does not do the the job, it only returns the longest match "aaaaa".
how can i get all the possible matches enumerated? Thanks!

g*g2009-05-26 07:05

2 楼

You should write an algorithm to get all the substring first,
then you can match one by one.

be:
".

【在 G*********a 的大作中提到】

: I want to obtain all the possible matches of "a" from "aaaaa", that should be:
: a
: aa
: aaa
: aaaa
: aaaaa
: but "a+" does not do the the job, it only returns the longest match "aaaaa".
: how can i get all the possible matches enumerated? Thanks!

t*r2009-05-26 07:05

3 楼

how about a{1,5} ?

I want to obtain all the possible matches of "a" from "aaaaa", that should
be:
a
aa
aaa
aaaa
aaaaa
but "a+" does not do the the job, it only returns the longest match "aaaaa".
how can i get all the possible matches enumerated? Thanks!

【在 G*********a 的大作中提到】

G*a2009-05-26 07:05

4 楼

yi? you have a daughter now?! she is so so so chobby and cute!
nod, since i can't get the regex do the work, i am post-process the returned
string myself.
thanks!

【在 g*****g 的大作中提到】

: You should write an algorithm to get all the substring first,
: then you can match one by one.
:
: be:
: ".

G*a2009-05-26 07:05

5 楼

thanks!
but it returns the longest one still:
aaaaa 0 5

".

【在 t**********r 的大作中提到】

: how about a{1,5} ?
:
: I want to obtain all the possible matches of "a" from "aaaaa", that should
: be:
: a
: aa
: aaa
: aaaa
: aaaaa
: but "a+" does not do the the job, it only returns the longest match "aaaaa".

g*e2009-05-26 07:05

6 楼

works for me in vi

【在 G*********a 的大作中提到】

: thanks!
: but it returns the longest one still:
: aaaaa 0 5
:
: ".

F*n2009-05-26 07:05

7 楼

If you want to do that in a program, you have to enumerate all substrings
and match them against the regex, because you don't have an index. There are
shortcuts.

returned

【在 G*********a 的大作中提到】

: yi? you have a daughter now?! she is so so so chobby and cute!
: nod, since i can't get the regex do the work, i am post-process the returned
: string myself.
: thanks!

G*a2009-05-26 07:05

8 楼

B*g2009-05-26 07:05

9 楼

co-ask，搞不出来

【在 G*********a 的大作中提到】

b*e2009-05-26 07:05

10 楼

How about use group and loop.
import java.util.regex.*;
public class test
{
public static void main(String[] args)
{
Pattern p = Pattern.compile("a(a*)");
String a = "aaaa";
match(a, p);
}
private static void match(String s, Pattern p)
{
Matcher m = p.matcher(s);
while (m.find())
{
System.out.println("found char = " + m.group(0));
match(m.group(1), p);
}
}
}