Re: loop iterator in a string

the "simple" way is using eval

  DB<53> say for eval "2,4..9"
2
4
5
6
7
8
9
[download]

NB: this might lead to problems with large intervals though, because foreach can't tell when to iterate lazily. But good enough if you don't intend to scale large.

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery}

Comment on Re: loop iterator in a string Download Code

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Re^2: loop iterator in a string by Anonymous Monk on Sep 27, 2021 at 18:41 UTC
Oh that's brilliant Rolf! I totally forgot about eval. This is definitely good enough for my use case. Thank you!	[reply]
Re^3: loop iterator in a string by haukex (Archbishop) on Sep 27, 2021 at 18:54 UTC
Please be aware that eval with anything other than a fixed, literal string (i.e. no variables interpolated in) has the potential to introduce security issues or other subtle bugs.	[reply]
Re^4: loop iterator in a string by LanX (Saint) on Sep 27, 2021 at 21:12 UTC
I think rejecting any `$str` containing anything which isn't a cipher, comma or dot prior to `eval $str` should be good enough `DB<53> $EVIL= ',@{[say "kill all kitties!"]}' DB<54> $str = "2,4..9" DB<55> p $str =~ m/[^0-9,.]/ # OK DB<56> $str .= $EVIL DB<57> p $str =~ m/[^0-9,.]/ # NOT OK 1 DB<58> eval $str kill all kitties!` [download] update in order to avoid syntax error you need to check `$@` to see if the eval was successful. NB line 82, not all errors are caught tho `DB<80> @list = eval ",1..3"; unless($@){say for @list } DB<81> @list = eval "1..3"; unless($@){say for @list } 1 2 3 DB<82> @list = eval "1.3"; unless($@){say for @list } 1.3` [download] Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l] [select]
Re^5: loop iterator in a string by haukex (Archbishop) on Sep 28, 2021 at 10:23 UTC
Re^6: loop iterator in a string by LanX (Saint) on Sep 28, 2021 at 10:53 UTC
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