Text::Diff::Table

Section: User Contributed Perl Documentation (3)
Updated: 2021-01-27
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NAME

  Text::Diff::Table - Text::Diff plugin to generate "table" format output

SYNOPSIS

  use Text::Diff;
  
  diff \@a, $b, { STYLE => "Table" };

DESCRIPTION

This is a plugin output formatter for Text::Diff that generates ``table'' style diffs:

  +--+----------------------------------+--+------------------------------+
  |  |../Test-Differences-0.2/MANIFEST  |  |../Test-Differences/MANIFEST  |
  |  |Thu Dec 13 15:38:49 2001          |  |Sat Dec 15 02:09:44 2001      |
  +--+----------------------------------+--+------------------------------+
  |  |                                  * 1|Changes                       *
  | 1|Differences.pm                    | 2|Differences.pm                |
  | 2|MANIFEST                          | 3|MANIFEST                      |
  |  |                                  * 4|MANIFEST.SKIP                 *
  | 3|Makefile.PL                       | 5|Makefile.PL                   |
  |  |                                  * 6|t/00escape.t                  *
  | 4|t/00flatten.t                     | 7|t/00flatten.t                 |
  | 5|t/01text_vs_data.t                | 8|t/01text_vs_data.t            |
  | 6|t/10test.t                        | 9|t/10test.t                    |
  +--+----------------------------------+--+------------------------------+

This format also goes to some pains to highlight ``invisible'' characters on differing elements by selectively escaping whitespace. Each element is split in to three segments (leading whitespace, body, trailing whitespace). If whitespace differs in a segement, that segment is whitespace escaped.

Here is an example of the selective whitespace.

  +--+--------------------------+--------------------------+
  |  |demo_ws_A.txt             |demo_ws_B.txt             |
  |  |Fri Dec 21 08:36:32 2001  |Fri Dec 21 08:36:50 2001  |
  +--+--------------------------+--------------------------+
  | 1|identical                 |identical                 |
  * 2|        spaced in         |        also spaced in    *
  * 3|embedded space            |embedded        tab       *
  | 4|identical                 |identical                 |
  * 5|        spaced in         |\ttabbed in               *
  * 6|trailing spaces\s\s\n     |trailing tabs\t\t\n       *
  | 7|identical                 |identical                 |
  * 8|lf line\n                 |crlf line\r\n             *
  * 9|embedded ws               |embedded\tws              *
  +--+--------------------------+--------------------------+

Here's why the lines do or do not have whitespace escaped:

lines 1, 4, 7 don't differ, no need.
lines 2, 3 differ in non-whitespace, no need.
lines 5, 6, 8, 9 all have subtle ws changes.

Whether or not line 3 should have that tab character escaped is a judgement call; so far I'm choosing not to.

UNICODE

To output the raw unicode chracters consult the documentation of Text::Diff::Config. You can set the "DIFF_OUTPUT_UNICODE" environment variable to 1 to output it from the command line. For more information, consult this bug: <https://rt.cpan.org/Ticket/Display.html?id=54214> .

LIMITATIONS

Table formatting requires buffering the entire diff in memory in order to calculate column widths. This format should only be used for smaller diffs.

Assumes tab stops every 8 characters, as $DIETY intended.

Assumes all character codes >= 127 need to be escaped as hex codes, ie that the user's terminal is ASCII, and not even ``high bit ASCII'', capable. This can be made an option when the need arises.

Assumes that control codes (character codes 0..31) that don't have slash-letter escapes (``\n'', ``\r'', etc) in Perl are best presented as hex escapes (``\x01'') instead of octal (``\001'') or control-code (``\cA'') escapes.

AUTHOR

Barrie Slaymaker <barries@slaysys.com>

LICENSE

You may use this software under the terms of the GNU public license, any version, or the Artistic license.