NAME

    String::Tagged::Terminal - format terminal output using String::Tagged

SYNOPSIS

     use String::Tagged::Terminal;
    
     my $st = String::Tagged::Terminal->new
        ->append( "Hello my name is " )
        ->append_tagged( $name, bold => 1, fgindex => 4 );
    
     $st->say_to_terminal;

DESCRIPTION

    This subclass of String::Tagged provides a method, build_terminal, for
    outputting the formatting tags embedded in the string as terminal
    escape sequences, to render the the output in the appropriate style.

TAGS

    The following tag names are recognised:

 bold, under, italic, strike, blink, reverse

    These tags take a boolean value. If the value is true then the
    corresponding terminal rendering attribute is enabled.

 altfont

    This tag takes an integer value. If defined it uses the "alternate font
    selection" sequence.

 fgindex, bgindex

    These tags take an integer value in the range 0 to 255. These select
    the foreground or background colour by using VGA, high-brightness
    extended 16 colour, or xterm 256 palette mode attributes, depending on
    the value.

    The ECMA-48-corrected string encoding form of CSI 38:5:nnn m is used to
    set the 256 palette values.

    Values will be rounded down to the nearest integer by calling int().
    This convenience allows things like the rand function for generating
    random colours:

       $st->append_tagged( "text", fgindex => 1 + rand 6 );

CONSTRUCTORS

 new_from_formatting

       $st = String::Tagged::Terminal->new_from_formatting( $fmt )

    Returns a new instance by converting String::Tagged::Formatting
    standard tags.

    Foreground and background colours are converted to their nearest index
    in the xterm 256 colour palette. The monospace Formatting attribute is
    rendered by selecting the first alternate font using altfont.

METHODS

    The following methods are provided in addition to those provided by
    String::Tagged.

 build_terminal

       $str = $st->build_terminal( %opts )

    Returns a string containing terminal escape sequences mixed with string
    content to render the string to a terminal.

    As this string will contain literal terminal control escape sequences,
    care should be taken when passing it around, printing it for debugging
    purposes, or similar.

    Takes the following additional named options:

    no_color

      If true, the fgindex and bgindex attributes will be ignored. This has
      the result of performing some formatting using the other attributes,
      but not setting colours.

 as_formatting

       $fmt = $st->as_formatting

    Returns a new String::Tagged instance tagged with
    String::Tagged::Formatting standard tags.

 print_to_terminal

       $str->print_to_terminal( $fh )

    Since version 0.03.

    Prints the string to the terminal by building a terminal escape string
    then printing it to the given IO handle (or STDOUT if not supplied).

    This method will pass the value of the NO_COLOR environment variable to
    the underlying "build_terminal" method call, meaning if that has a true
    value then colouring tags will be ignored, yielding a monochrome
    output. This follows the suggestion of http://no-color.org/.

 say_to_terminal

       $str->say_to_terminal( $fh )

    Since version 0.03.

    Prints the string to the terminal as per "print_to_terminal", followed
    by a linefeed.

COMPATIBILITY NOTES

    On Windows, the following notes apply:

      * On all versions of Windows, the attributes bold, fgindex and
      bgindex are supported. The bold attribute is implemented by using
      high-intensity colours, so will be indistinguishable from using
      high-intensity colour indexes without bold. The full 256-color
      palette is not supported by Windows, so it is down-converted to the
      16 colours that are.

      * Starting with Windows 10, also under and reverse are supported.

      * The attributes italic, strike, altfont, blink are not supported on
      any Windows version.

      * On Windows, only a single output console is supported.

TODO

      * Consider a ->parse_terminal constructor method, which would attempt
      to parse SGR sequences from a given source string.

AUTHOR

    Paul Evans <leonerd@leonerd.org.uk>