in reply to (tye)Re: Slicing a string on words
in thread Slicing a string on words

Very nice solution, tye!!

There's a small typo in the regex (a surplus parenthesis), so here goes the code again, corrected 

$window_size--;
my( $windowed_text )= $text_body =~
    /^\s*(?:\S+\s+){$window_start}(\S+(?:\s+\S+){0,$window_size})/;

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What I wanted to add is that Perl handles the boundary cases very nicely, so no extra handling required for $window_start = 0 or $window_size = 0. This means 
$_ = q/01234/;
/^..{0}/;    # matches '0'
/^..{0,0}/;  # matches '0'
/^..{0,-1}/; # doesn't match at all

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which is exactly what we need for the code to work fine.

-- Hofmator

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(tye)Re2: Slicing a string on words
by tye (Sage) on Aug 28, 2001 at 21:31 UTC

    Thanks. Note that $window_size of 0 will probably behave the same as $window_size of 1, though.

    Update: Sorry, wrong. I misunderstood your examples. /..{0,-1}/ matches any two characters followed by the literal string "{0,-1}". This could still be a problem for certain input values, but such seem pretty unlikely. So you might want some special code for the boundary case, depending on how varied your inputs might be.

            - tye (but my friends call me "Tye")
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