Edit File: Algorithm::DiffOld.3pm
.\" Automatically generated by Pod::Man 2.27 (Pod::Simple 3.28) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is turned on, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{ . if \nF \{ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "Algorithm::DiffOld 3" .TH Algorithm::DiffOld 3 "2020-12-14" "perl v5.16.3" "User Contributed Perl Documentation" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" Algorithm::DiffOld \- Compute `intelligent' differences between two files / lists but use the old (<=0.59) interface. .SH "NOTE" .IX Header "NOTE" This has been provided as part of the Algorithm::Diff package by Ned Konz. This particular module is \fB\s-1ONLY\s0\fR for people who \fB\s-1HAVE\s0\fR to have the old interface, which uses a comparison function rather than a key generating function. .PP Because each of the lines in one array have to be compared with each of the lines in the other array, this does M*N comparisons. This can be very slow. I clocked it at taking 18 times as long as the stock version of Algorithm::Diff for a 4000\-line file. It will get worse quadratically as array sizes increase. .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& use Algorithm::DiffOld qw(diff LCS traverse_sequences); \& \& @lcs = LCS( \e@seq1, \e@seq2, $comparison_function ); \& \& $lcsref = LCS( \e@seq1, \e@seq2, $comparison_function ); \& \& @diffs = diff( \e@seq1, \e@seq2, $comparison_function ); \& \& traverse_sequences( \e@seq1, \e@seq2, \& { MATCH => $callback, \& DISCARD_A => $callback, \& DISCARD_B => $callback, \& }, \& $comparison_function ); .Ve .SH "COMPARISON FUNCTIONS" .IX Header "COMPARISON FUNCTIONS" Each of the main routines should be passed a comparison function. If you aren't passing one in, \fBuse Algorithm::Diff instead\fR. .PP These functions should return a true value when two items should compare as equal. .PP For instance, .PP .Vb 1 \& @lcs = LCS( \e@seq1, \e@seq2, sub { my ($a, $b) = @_; $a eq $b } ); .Ve .PP but if that is all you're doing with your comparison function, just use Algorithm::Diff and let it do this (this is its default). .PP Or: .PP .Vb 5 \& sub someFunkyComparisonFunction \& { \& my ($a, $b) = @_; \& $a =~ m{$b}; \& } \& \& @diffs = diff( \e@lines, \e@patterns, \e&someFunkyComparisonFunction ); .Ve .PP which would allow you to diff an array \f(CW@lines\fR which consists of text lines with an array \f(CW@patterns\fR which consists of regular expressions. .PP This is actually the reason I wrote this version \*(-- there is no way to do this with a key generation function as in the stock Algorithm::Diff.