oro regular expression

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Robert Mark Bram - 16 Mar 2006 06:50 GMT

Hi All,

I want an expression that will allow a decimal number or a specific
string. For example, I want the following to be valid:

.1
1
1.1
-.1
-1
-1.1
remove
REMOVE
REmove

Here is the regular expression I am testing:
-{0,1}\d{0,5}(\.(\d){0,2})?|(?i)REMOVE
It accepts the numbers, but not the strings.

If I use this:
-{0,1}\d{1,5}(\.(\d){0,2})?|(?i)REMOVE
it accepts the string and most numbers, but not this:
.1

I am testing with this demo applet:
http://jakarta.apache.org/oro/demo.html

Can anyone figure what I am doing wrong? Any help would be most
appreciated!

Rob

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Robert Mark Bram - 16 Mar 2006 06:57 GMT

I have a solution, but I don't understand why it works:
(?i)REMOVE|(-?\d{0,5}(\.)?\d{0,2})

This now accepts all the combinations I wanted, but I don't understand
why.... :)

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Robert Mark Bram - 16 Mar 2006 07:05 GMT

*sigh*

Actually, that 'solution' doesn't work for 1, 11 etc. mm.. :(

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Oliver Wong - 16 Mar 2006 19:47 GMT

> Hi All,
>
[quoted text clipped - 19 lines]
> it accepts the string and most numbers, but not this:
> .1

Draw a DFA and convert it to an RE. Read Michael Sipser's book
"Introduction to the Theory of Computation" if you don't know how. I'd do it
for you, but it's a lot of effort, and you wouldn't understand how I got to
my result unless you knew Sipser's method. =/

- Oliver

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Alan Krueger - 17 Mar 2006 05:14 GMT

> Here is the regular expression I am testing:
> -{0,1}\d{0,5}(\.(\d){0,2})?|(?i)REMOVE
> It accepts the numbers, but not the strings.

[...]

> I am testing with this demo applet:
> http://jakarta.apache.org/oro/demo.html

Curiously, it appears to work with java.util.Pattern.

http://www.cis.upenn.edu/~matuszek/General/RegexTester/regex-tester.html

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oro regular expression

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