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

VERSION
    version 0.05

SYNOPSIS
     use Text::ANSI::Util qw(
         ta_detect ta_length ta_mbpad ta_mbswidth ta_mbswidth_height ta_mbwrap
         ta_pad ta_strip ta_wrap);

     # detect whether text has ANSI escape codes?
     say ta_detect("red");         # => false
     say ta_detect("\x1b[31mred"); # => true

     # calculate length of text (excluding the ANSI escape codes)
     say ta_length("red");         # => 3
     say ta_length("\x1b[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("\x1b[31mred"); # => 3
     say ta_mbswidth("\x1b[31m红色"); # => 4

     # ditto, but also return the number of lines
     say ta_mbswidth_height("\x1b[31mred\n红色"); # => [4, 2]

     # strip ANSI escape codes
     say ta_strip("\x1b[31mred"); # => "red"

     # split codes (ANSI codes are always on the even positions)
     my @parts = ta_split_codes("\x1b[31mred"); # => ("", "\x1b[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(...);

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_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("foobar\nb\n")" gives [6, 3].

  ta_strip($text) => STR
    Strip ANSI escape codes from $text, returning the stripped 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_wrap($text, $width) => STR
    Wrap $text to $width columns.

    $width defaults to 80 if not specified.

    Note: currently performance is rather abysmal (~ 1200/s on my Core
    i5-2400 3.1GHz desktop for a ~ 1KB of text), so call this routine
    sparingly ;-).

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

    Note: for text which does not have whitespaces between words, like
    Chinese, you will have to separate the words first (e.g. using
    Lingua::ZH::WordSegmenter). The module also currently does not handle
    whitespace-like characters other than ASCII 32 (for example, the Chinese
    dot 。).

    Note: currently performance is rather abysmal (~ 1000/s on my Core
    i5-2400 3.1GHz desktop for a ~ 1KB of text), so call this routine
    sparingly ;-).

  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.

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

TODOS
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.