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in reply to Re: search, replace and backrefrences
in thread search, replace and backrefrences

Well, im not real sure that $1_0_0_ isnt being treated as such.

Variable names that start with a digit may only have
more digits in the name.

This seems a murky area. my $99; throws an error.

This post has little to do with the original question.

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Re: Re: Re: search, replace and backrefrences
by diotalevi (Canon) on Sep 30, 2002 at 16:56 UTC

    Even with the number formatting semantics where 1_000_000 == 1000000?

[reply]
[d/l]
      Even with the number formatting semantics where 1_000_000 == 1000000?

      Yes this use of underscores is only for numeric literals.

[reply]
Re: Re: Re: search, replace and backrefrences
by demerphq (Chancellor) on Sep 30, 2002 at 19:27 UTC
    Variable names that start with a digit may only have more digits in the name.

    Cool. I didnt know that. What perldoc is it in?

    This seems a murky area. my $99; throws an error.

    Well, i agree its weird, but its not that murky. All of the ^\d+$ variables are global only and cannot be my()ed (and all of the scalars are read only).

    --- demerphq
    my friends call me, usually because I'm late....

[reply]
      I was about to say murky, but unimportant but bit my tongue
      as everything is important to someone.

      It seems unclear what behavior is intended, i.e. murky.
      Why shouldn't I be able to my $99;?   I haven't seen anything to
      suggest it is illegal. Or why is $123456 read-only?

      Is this documented somewhere? Point me at it.

      I'm pretty sure I got that from the Camel book.

[reply]
[d/l]
[select]
        Its partly documented in perlvar but mostly in the camel. Basically all the digit scalars are used for doing pattern match storage. Apparently one of the other scripting langugae had a limit (i think 9) on the number of capture buffers allowed. I believe it was a matter of pride that perl could handle an unbounded number (ykwim). And as all of the capture buffers are read-only that makes them all read only. The lexical bit I dont remember. :-)

        --- demerphq
        my friends call me, usually because I'm late....

[reply]
        From perldoc perlvar:
        $<digits>
        Contains the subpattern from the corresponding set of parentheses in the last pattern matched, not counting patterns matched in nested blocks that have been exited already. (Mnemonic: like \digits.) These variables are all read-only.

        Cheers,
        Shendal
[reply]

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