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[vwnc] Missing Regex "lookaround" support

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Runar Jordahl

[vwnc] Missing Regex "lookaround" support

Package Regex11 found in the Public Store Repository (and also bundled
with 7.5) seems to be lacking Regex "lookaround"
(http://www.regular-expressions.info/lookaround.html). If you for
example evaluate the statement below, a "nullable closure" exception
is raised.

'o(?=k)' asRegex

Is this a bug or simply missing support for some Regex functions?

Runar
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Reinout Heeck

Re: [vwnc] Missing Regex "lookaround" support

On Apr 30, 2008, at 9:25 AM, Runar Jordahl wrote:

> Package Regex11 found in the Public Store Repository (and also bundled
> with 7.5) seems to be lacking Regex "lookaround"
>
> (http://www.regular-expressions.info/lookaround.html). If you for
> example evaluate the statement below, a "nullable closure" exception
> is raised.
>
> 'o(?=k)' asRegex
>
> Is this a bug or simply missing support for some Regex functions?

The Regex parcel is well documented (once you find the documentation -
on the class side of RxParser).
As far as I know the documentation is complete with respect to the
implemented language.

Lookaround is not supported yet but given that the code base was
designed towards implementation simplicity it may be not too hard to
add support for it yourself.

R
-

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Steven Kelly

Re: [vwnc] Missing Regex "lookaround" support

In reply to this post by Runar Jordahl

Lookarounds aren't supported, and neither are limited repetitions like
a{0,3} to match zero to three a's. IIRC, of the well-known
implementations of regular expressions, POSIX ERE is the closest to
Regex11.
http://www.regular-expressions.info/refflavors.html

Compared to POSIX ERE, Regex11 has (at least) the following missing (-)
and extra (+) features:
- limited repetitions
+ \d \w \s etc. shorthands

The nullable closure exception is raised because inside your submatch
(?=k) the ? is interpreted in the only way supported by Regex11: zero or
one repetitions of the preceding element (e.g. 'ba?b' matches 'bb' or
'bab'). As there is no preceding element, ? is not legal there.

HTH,
Steve

> -----Original Message-----
> From: [hidden email] [mailto:[hidden email]] On
> Behalf Of Runar Jordahl
> Sent: Wednesday, 30 April 2008 10:25
> To: vwnc
> Subject: [vwnc] Missing Regex "lookaround" support
>
> Package Regex11 found in the Public Store Repository (and also bundled
> with 7.5) seems to be lacking Regex "lookaround"
> (http://www.regular-expressions.info/lookaround.html). If you for
> example evaluate the statement below, a "nullable closure" exception
> is raised.
>
> 'o(?=k)' asRegex
>
> Is this a bug or simply missing support for some Regex functions?
>
> Runar
> _______________________________________________
> vwnc mailing list
> [hidden email]
> http://lists.cs.uiuc.edu/mailman/listinfo/vwnc

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Carl Gundel

[vwnc] Size of OS X virtual machines

In reply to this post by Reinout Heeck

I'm somewhat baffled by the huge difference in the size of virtual
machines for WIndows versus OS X. The VM for Windows is less than a
megabyte, but the x86 VM for OS X is more than 9MB, and the universal
binary for OS X is more than 20MB.

Why is this, and is there anything to be done about it?

-Carl Gundel
http://www.runbasic.com
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Mike Hales

Re: [vwnc] Size of OS X virtual machines

The app bundle is 20MB, but it contains 6 vms. The actual vm is 2.5
MB and only 2.2 for the X11 one. When you make your own app bundle
with your image as a resource you can strip out the other ones. Your
bundle should be the size of your image + 2.5 for the vm + a few
hundred k for icons, plist etc. There are good instructions in the
packaging directory of the vw install.

Mike

On Apr 30, 2008, at 9:41 AM, Carl Gundel wrote:

> I'm somewhat baffled by the huge difference in the size of virtual
> machines for WIndows versus OS X. The VM for Windows is less than a
> megabyte, but the x86 VM for OS X is more than 9MB, and the universal
> binary for OS X is more than 20MB.
>
> Why is this, and is there anything to be done about it?
>
> -Carl Gundel
> http://www.runbasic.com
> _______________________________________________
> vwnc mailing list
> [hidden email]
> http://lists.cs.uiuc.edu/mailman/listinfo/vwnc

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Carl Gundel

Re: [vwnc] Size of OS X virtual machines

Thanks. I didn't realize that this was a special sort of package
file. I probably should have known it was something like that. So
much to learn.

-Carl Gundel
http://www.runbasic.com

On Apr 30, 2008, at 2:16 PM, Mike Hales wrote:

> The app bundle is 20MB, but it contains 6 vms. The actual vm is 2.5
> MB and only 2.2 for the X11 one. When you make your own app bundle
> with your image as a resource you can strip out the other ones.
> Your bundle should be the size of your image + 2.5 for the vm + a
> few hundred k for icons, plist etc. There are good instructions in
> the packaging directory of the vw install.
>
> Mike
>
>
> On Apr 30, 2008, at 9:41 AM, Carl Gundel wrote:
>
>> I'm somewhat baffled by the huge difference in the size of virtual
>> machines for WIndows versus OS X. The VM for Windows is less than a
>> megabyte, but the x86 VM for OS X is more than 9MB, and the universal
>> binary for OS X is more than 20MB.
>>
>> Why is this, and is there anything to be done about it?
>>
>> -Carl Gundel
>> http://www.runbasic.com
>> _______________________________________________
>> vwnc mailing list
>> [hidden email]
>> http://lists.cs.uiuc.edu/mailman/listinfo/vwnc
>

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