in reply to Re: Re: Requiring backtracking a certain number of times
in thread Requiring backtracking a certain number of times

what I really want is some way of addressing all the characters in a string/number, apply some function to it that returns a number, then add those numbers up. 

$_=6491;
sum(some_function(split//));

[download]
Use your favourite sum(), and your favorite some_function() ;)

These things are very hard, and I think completely impossible with regexes.
Although... 
s/(\d)/$s+=$1/ge; # $s is the sum...

# Which leaves garbage in $_, but is a single stroke shorter than:

$s+=$_ for split//;

# But thenagain, this is even shorter:

$s+=$_ for/./g;

[download]

U28geW91IGNhbiBhbGwgcm90MTMgY
W5kIHBhY2soKS4gQnV0IGRvIHlvdS
ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
geW91IHNlZSBpdD8gIC0tIEp1ZXJk

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Re: Requiring backtracking a certain number of times
by ferrency (Deacon) on Apr 04, 2002 at 18:24 UTC
    I went down this same track, and came up with a version that doesn't munge $_:

    s/(\d)/$s+=$1,$1/ge;

    [download]
    Although I was hampered by the fact that this doesn't work in psh for some reason.

    Alan

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      After playing, I came up with: 
      @a=/.(?{$s+=$&})/g;

      [download]
      However, I have to have the @a=. If you run it without that, it only deals with the first number. *blinkblink* That's just so counter-intuitive.

      ------
      We are the carpenters and bricklayers of the Information Age.

      Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

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