NAME
    Text::ANSI::Util - Routines for text containing ANSI escape codes

VERSION
    version 0.08

SYNOPSIS
     use Text::ANSI::Util qw(
         ta_add_color_resets
         ta_detect ta_highlight ta_highlight_all ta_length ta_mbpad ta_mbswidth
         ta_mbswidth_height ta_mbwrap ta_pad ta_split_codes ta_split_codes_single
         ta_strip ta_wrap);

     # detect whether text has ANSI escape codes?
     say ta_detect("red");         # => false
     say ta_detect("\e[31mred"); # => true

     # calculate length of text (excluding the ANSI escape codes)
     say ta_length("red");         # => 3
     say ta_length("\e[31mred"); # => 3

     # calculate visual width of text if printed on terminal (can handle Unicode
     # wide characters and exclude the ANSI escape codes)
     say ta_mbswidth("\e[31mred"); # => 3
     say ta_mbswidth("\e[31mçº¢è²"); # => 4

     # ditto, but also return the number of lines
     say ta_mbswidth_height("\e[31mred\nçº¢è²"); # => [4, 2]

     # strip ANSI escape codes
     say ta_strip("\e[31mred"); # => "red"

     # split codes (ANSI codes are always on the even positions)
     my @parts = ta_split_codes("\e[31mred"); # => ("", "\e[31m", "red")

     # wrap text to a certain column width, handle ANSI escape codes
     say ta_wrap("....", 40);

     # ditto, but handle wide characters
     say ta_mbwrap(...);

     # pad (left, right, center) text to a certain width, handles multiple lines
     say ta_pad("foo", 10);                          # => "foo       "
     say ta_pad("foo", 10, "left");                  # => "       foo"
     say ta_pad("foo\nbarbaz\n", 10, "center", "."); # => "...foo....\n..barbaz..\n"

     # ditto, but handle wide characters
     say ta_mbpad(...);

     # truncate text to a certain width while still passing ANSI escape codes
     use Term::ANSIColor;
     my $text = color("red")."red text".color("reset"); # => "\e[31mred text\e[0m"
     say ta_trunc($text, 5);           # => "\e[31mred t\e[0m"

     # ditto, but handle wide characters
     say ta_mbtrunc(...);

     # highlight the first occurence of some string within text
     say ta_highlight("some text", "ome", "\x[7m\x[31m");

     # ditto, but highlight all occurrences
     say ta_highlight_all(...);

DESCRIPTION
    This module provides routines for dealing with text containing ANSI
    escape codes (mainly ANSI color codes).

    Current caveats:

    *   All codes are assumed to have zero width

        This is true for color codes and some other codes, but there are
        also codes to alter cursor positions which means they can have
        negative or undefined width.

    *   Single-character CSI (control sequence introducer) currently ignored

        Only "ESC+[" (two-character CSI) is currently parsed.

        BTW, in ASCII terminals, single-character CSI is 0x9b. In UTF-8
        terminals, it is "0xc2, 0x9b" (2 bytes).

    *   Private-mode- and trailing-intermediate character currently not
        parsed

FUNCTIONS
  ta_detect($text) => BOOL
    Return true if $text contains ANSI escape codes, false otherwise.

  ta_length($text) => INT
    Count the number of bytes in $text, while ignoring ANSI escape codes.
    Equivalent to "length(ta_strip($text)". See also: ta_mbswidth().

  ta_length_height($text) => [INT, INT]
    Like ta_length(), but also gives height (number of lines). For example,
    "ta_length_height("foobar\nb\n")" gives [6, 3].

  ta_mbswidth($text) => INT
    Return visual width of $text (in number of columns) if printed on
    terminal. Equivalent to "Text::CharWidth::mbswidth(ta_strip($text))".
    This function can be used e.g. in making sure that your text aligns
    vertically when output to the terminal in tabular/table format.

    Note: "mbswidth()" handles "\0" correctly (regard it as having zero
    width) but currently does not handle control characters like "\n", "\t",
    "\b", "\r", etc well (they are just counted as having -1). So make sure
    that your text does not contain those characters.

    But at least ta_mbswidth() handles multiline text correctly, e.g.:
    "ta_mbswidth("foo\nbarbaz")" gives 6 instead of 3-1+8 = 8. It splits the
    input text first against "/\r?\n/".

  ta_mbswidth_height($text) => [INT, INT]
    Like ta_mbswidth(), but also gives height (number of lines). For
    example, "ta_mbswidth_height("西爪哇\nb\n")" gives [6, 3].

  ta_strip($text) => STR
    Strip ANSI escape codes from $text, returning the stripped text.

  ta_extract_codes($text) => STR
    This is the opposite of ta_strip(), return only the ANSI codes in $text.

  ta_split_codes($text) => LIST
    Split $text to a list containing alternating ANSI escape codes and text.
    ANSI escape codes are always on the second element, fourth, and so on.
    Example:

     ta_split_codes("");              # => ()
     ta_split_codes("a");             # => ("a")
     ta_split_codes("a\e[31m");       # => ("a", "\e[31m")
     ta_split_codes("\e[31ma");       # => ("", "\e[31m", "a")
     ta_split_codes("\e[31ma\e[0m");  # => ("", "\e[31m", "a", "\e[0m")
     ta_split_codes("\e[31ma\e[0mb"); # => ("", "\e[31m", "a", "\e[0m", "b")
     ta_split_codes("\e[31m\e[0mb");  # => ("", "\e[31m\e[0m", "b")

    so you can do something like:

     my @parts = ta_split_codes($text);
     while (my ($text, $ansicode) = splice(@parts, 0, 2)) {
         ...
     }

  ta_split_codes_single($text) => LIST
    Like ta_split_codes() but each ANSI escape code is split separately,
    instead of grouped together.

  ta_wrap($text, $width, \%opts) => STR
    Like Text::WideChar::Util's wrap() except handles ANSI escape codes.
    Perform color reset at the end of each line and a color restart at the
    start of subsequent line so the text is safe for combining in a
    multicolumn/tabular layout.

    Options:

    *   flindent => STR

        First line indent. See Text::WideChar::Util for more details.

    *   slindent => STR

        First line indent. See Text::WideChar::Util for more details.

    *   tab_width => INT (default: 8)

        First line indent. See Text::WideChar::Util for more details.

    *   pad => BOOL (default: 0)

        If set to true, will pad each line to $width. This is convenient if
        you need the lines padded, saves calls to ta_pad().

    Performance: ~750/s on my Core i5-2400 3.1GHz desktop for a ~1KB of text
    (with zero to moderate amount of color codes). As a comparison,
    Text::WideChar::Util's wrap() can do about 3100/s.

  ta_mbwrap($text, $width, \%opts) => STR
    Like ta_wrap(), but it uses ta_mbswidth() instead of ta_length(), so it
    can handle wide characters.

    Performance: ~650/s on my Core i5-2400 3.1GHz desktop for a ~1KB of text
    (with zero to moderate amount of color codes). As a comparison,
    Text::WideChar::Util's mbwrap() can do about 2300/s.

  ta_add_color_resets(@text) => LIST
    Make sure that a color reset command (add "\e[0m]") to the end of each
    element and a color restart (add all the color codes from the previous
    element, from the last color reset) to the start of the next element,
    and so on. Return the new list.

    This makes each element safe to be combined with other array of text
    into a single line, e.g. in a multicolumn/tabular layout. An example:

    Without color resets:

     my @col1 = split /\n/, "\e[31mred\nmerah\e[0m";
     my @col2 = split /\n/, "\e[32mgreen\e[1m\nhijau tebal\e[0m";

     printf "%s | %s\n", $col1[0], $col2[0];
     printf "%s | %s\n", $col1[1], $col2[1];

    the printed output:

     \e[31mred | \e[32mgreen
     merah\e[0m | \e[1mhijau tebal\e[0m

    The "merah" text on the second line will become green because of the
    effect of the last color command printed ("\e[32m"). However, with
    ta_add_color_resets():

     my @col1 = ta_add_color_resets(split /\n/, "\e[31mred\nmerah\e[0m");
     my @col2 = ta_add_color_resets(split /\n/, "\e[32mgreen\e[1m\nhijau tebal\e[0m");

     printf "%s | %s\n", $col1[0], $col2[0];
     printf "%s | %s\n", $col1[1], $col2[1];

    the printed output ("<...>") marks the code added by
    ta_add_color_resets():

     \e[31mred<\e[0m> | \e[32mgreen\e[1m<\e[0m>
     <\e[31m>merah\e[0m | <\e[32m\e[1m>hijau tebal\e[0m

    All the cells are printed with the intended colors.

  ta_pad($text, $width[, $which[, $padchar[, $truncate]]]) => STR
    Return $text padded with $padchar to $width columns. $which is either
    "r" or "right" for padding on the right (the default if not specified),
    "l" or "left" for padding on the right, or "c" or "center" or "centre"
    for left+right padding to center the text.

    $padchar is whitespace if not specified. It should be string having the
    width of 1 column.

    Does *not* handle multiline text; you can split text by "/\r?\n/"
    yourself.

  ta_mbpad => STR
    Like ta_pad() but it uses ta_mbswidth() instead of ta_length(), so it
    can handle wide characters.

  ta_trunc($text, $width) => STR
    Truncate $text to $width columns while still including all the ANSI
    escape codes. This ensures that truncated text still reset colors, etc.

    Does *not* handle multiline text; you can split text by "/\r?\n/"
    yourself.

  ta_mbtrunc($text, $width) => STR
    Like ta_trunc() but it uses ta_mbswidth() instead of ta_length(), so it
    can handle wide characters.

  ta_highlight($text, $needle, $color) => STR
    Highlight the first occurence of $needle in $text with <$color>, taking
    care not to mess up existing colors.

    $needle can be a string or a Regexp object.

    Performance: ~ 20k/s on my Core i5-2400 3.1GHz desktop for a ~ 1KB of
    text and a needle of length ~ 7.

    Implementation note: to not mess up colors, we save up all color codes
    from the last reset ("\e[0m]") before inserting the highlight color +
    highlight text. Then we issue "\e[0m" and the saved up color code to
    return back to the color state before the highlight is inserted. This is
    the same technique as described in ta_add_color_resets().

  ta_highlight_all($text, $needle, $color) => STR
    Like ta_highlight(), but highlight all occurences instead of only the
    first.

    Performance: ~ 4k/s on my Core i5-2400 3.1GHz desktop for a ~ 1KB of
    text and a needle of length ~ 7 and number of occurences ~ 13.

FAQ
  How do I truncate string based on number of characters?
    You can simply use ta_trunc() even on text containing wide characters.
    ta_trunc() uses Perl's length() which works on a per-character basis.

  How do I highlight a string case-insensitively?
    You can currently use a regex for the $needle and use the "i" modifier.
    Example:

     use Term::ANSIColor;
     ta_highlight($text, qr/\b(foo)\b/i, color("bold red"));

TODOS
    *   ta_split

        A generalized version of ta_split_lines().

SEE ALSO
    Term::ANSIColor

AUTHOR
    Steven Haryanto <stevenharyanto@gmail.com>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2013 by Steven Haryanto.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.

