compiled regex (?: \/ foo) matches and returns 'undef'

[pxs42]

( ?: \/ whatever ) matches and returns undef when compiled. the attached perl code I hope is self documenting. What it doesn't show is the different possible flavors of escaping the \/ - ie [\/], \\ \/ - which also fail in the same way.

Any help would be much appreciated.

 

[MillerH]

If you want help, it is easier on those helping you if you just include your code in [ignore]

your code here

[/ignore] tags instead of using an attachment.

Here is your code so included:

[url=http://perldoc.perl.org/functions/use.html][black][b]use[/b][/black][/url] [green]strict[/green][red];[/red]

[url=http://perldoc.perl.org/functions/sub.html][black][b]sub[/b][/black][/url] [maroon]testit[/maroon] [red]{[/red]
  [url=http://perldoc.perl.org/functions/print.html][black][b]print[/b][/black][/url] [url=http://perldoc.perl.org/functions/shift.html][black][b]shift[/b][/black][/url],[red]'[/red][purple]: [/purple][red]'[/red],[black][b]shift[/b][/black], [red]"[/red][purple][purple][b]\n[/b][/purple][/purple][red]"[/red][red];[/red]
  [url=http://perldoc.perl.org/functions/map.html][black][b]map[/b][/black][/url] [red]{[/red] [black][b]print[/b][/black] [maroon]STDOUT[/maroon] [red]([/red] [url=http://perldoc.perl.org/functions/defined.html][black][b]defined[/b][/black][/url] [blue]$_[/blue] ? [blue]$_[/blue] : [red]'[/red][purple]undef[/purple][red]'[/red] [red])[/red] . [red]"[/red][purple][purple][b]\n[/b][/purple][/purple][red]"[/red] [red]}[/red]  [blue]@_[/blue][red];[/red]
[red]}[/red]

[url=http://perldoc.perl.org/functions/my.html][black][b]my[/b][/black][/url] [blue]$s[/blue] = [red]'[/red][purple]hello mary [/purple][red]'[/red][red];[/red]

[url=http://perldoc.perl.org/functions/our.html][black][b]our[/b][/black][/url] [red]([/red][blue]$tword[/blue],[blue]$tdashed[/blue],[blue]$tslashed[/blue][red])[/red][red];[/red]

[black][b]print[/b][/black] [red]"[/red][purple]uncompiled .... [purple][b]\n[/b][/purple][purple][b]\n[/b][/purple][/purple][red]"[/red][red];[/red]

[blue]$tword[/blue]    = [red]"[/red][purple] [A-Za-z] + [/purple][red]"[/red] [red];[/red]
[blue]$tdashed[/blue]  = [red]"[/red][purple] [blue]$tword[/blue] ( ?: - [blue]$tword[/blue] ) [purple][b]\*[/b][/purple] [/purple][red]"[/red][red];[/red]
[blue]$tslashed[/blue] = [red]"[/red][purple] [blue]$tword[/blue] ( [blue]$:[/blue] [purple][b]\\[/b][/purple] [purple][b]\/[/b][/purple] [blue]$tword[/blue] ) * [/purple][red]"[/red][red];[/red]

[maroon]testit[/maroon][red]([/red][blue]$tdashed[/blue], [blue]$s[/blue], [blue]$s[/blue] =~ [red]/[/red][purple] [blue]$tdashed[/blue] [/purple][red]/[/red][red]gx[/red][red])[/red][red];[/red]
[maroon]testit[/maroon][red]([/red][blue]$tslashed[/blue], [blue]$s[/blue], [blue]$s[/blue] =~ [red]/[/red][purple] [blue]$tslashed[/blue] [/purple][red]/[/red][red]gx[/red][red])[/red][red];[/red]

[black][b]print[/b][/black] [red]"[/red][purple][purple][b]\n[/b][/purple][purple][b]\n[/b][/purple]compiled .... [purple][b]\n[/b][/purple][purple][b]\n[/b][/purple][/purple][red]"[/red][red];[/red]

[blue]$tword[/blue]    = [red]qr/[/red][purple] [A-Za-z] + [/purple][red]/[/red][red]x[/red][red];[/red]
[blue]$tdashed[/blue]  = [red]qr/[/red][purple] [blue]$tword[/blue] ( ?: - [blue]$tword[/blue] ) * [/purple][red]/[/red][red]x[/red][red];[/red]
[blue]$tslashed[/blue] = [red]qr/[/red][purple] [blue]$tword[/blue] ( [blue]$:[/blue] [purple][b]\\[/b][/purple] [purple][b]\/[/b][/purple] [blue]$tword[/blue] ) * [/purple][red]/[/red][red]x[/red][red];[/red]

[maroon]testit[/maroon][red]([/red][blue]$tdashed[/blue], [blue]$s[/blue], [blue]$s[/blue] =~ [red]/[/red][purple] [blue]$tdashed[/blue] [/purple][red]/[/red][red]gx[/red][red])[/red][red];[/red]
[maroon]testit[/maroon][red]([/red][blue]$tslashed[/blue], [blue]$s[/blue], [blue]$s[/blue] =~ [red]/[/red][purple] [blue]$tslashed[/blue] [/purple][red]/[/red][red]gx[/red][red])[/red][red];[/red]

[black][b]print[/b][/black] [red]"[/red][purple][purple][b]\n[/b][/purple][purple][b]\n[/b][/purple]inline .... [purple][b]\n[/b][/purple][purple][b]\n[/b][/purple][/purple][red]"[/red][red];[/red]

[maroon]testit[/maroon][red]([/red][blue]$tdashed[/blue], [blue]$s[/blue], [blue]$s[/blue] =~ [red]/[/red][purple] [A-Za-z] + ( ?: - [A-Za-z] + ) * [/purple][red]/[/red][red]gx[/red][red])[/red][red];[/red]
[maroon]testit[/maroon][red]([/red][blue]$tslashed[/blue], [blue]$s[/blue], [blue]$s[/blue] =~ [red]/[/red][purple] [A-Za-z] + ( ?: [purple][b]\/[/b][/purple] [A-Za-z] + ) * [/purple][red]/[/red][red]gx[/red][red])[/red][red];[/red]

[tt]------------------------------------------------------------
Pragmas (perl 5.8.8) used :
[ul]
[li]strict - Perl pragma to restrict unsafe constructs[/li]
[/ul]
[/tt]

- Miller

 

[travs69]

add double quotes around your data when you pass it to the sub
i.e.

testit($tdashed, $s, "$s =~ / [A-Za-z] + ( ?: - [A-Za-z] + ) * /gx");
testit($tslashed, $s, "$s =~ / [A-Za-z] + ( ?: \/ [A-Za-z] + ) * /gx");

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Travis - Those who say it cannot be done are usually interrupted by someone else doing it; Give the wrong symptoms, get the wrong solutions;