Key Word In Context system (golf, anyone)?

[Falkkin]

sub f{@a=();for(@_){push @_,shift;push @a,"@_"}@a}push@_,f split while
+ <>;print join "\n",sort @_

This program implements the Key Word In Context (KWIC) index system (in 98 bytes). This system accepts a sequence of lines of text and circularly shifts each line by repeatedly removing the first word and appending it to the end of the line. The KWIC system then outputs a listing of all circular shifts of all lines, in sorted order.

Run it with perl kwic.pl filename, where filename contains the lines you want to apply the KWIC system to.

This can probably be done more compactly... anybody out there got a shorter solution?

[danger]

I believe this'll do it in 60 bytes:

print sort map{sub{map{push@_,shift;"@_\n"}@_}->(split)}<>

update: Yup, I can't count ... 58 characters showing (59 bytes if we include a terminal newline in our file).

[btrott]

This is a bit shorter:

    % perl -n -e 'sub f{map{push@_,shift;"@_"}@_}push@b,f split;END{$,
+="\n";print sort@b}' filename

The actual code here (between the single quotes) is 72 chars. Though that's cheating slightly since you need the -n to make it work.

Should have the same output. I'm sure there's a faster/shorter way to do that f sub. Someone'll come up with it.

[jmcnamara]

How about this, 45 bytes perl + 5 bytes for the pipe and sort:

perl -lane'for(@F){print"@F";push@F,shift@F}' file |sort


Or with an internal sort, 68 bytes:

perl -lane'for(@F){push@E,"@F";push@F,shift@F}END{print for sort@E}' f
+ile


John.
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