Module: CovLoupe::OutputChars

Defined in:
lib/cov_loupe/output_chars.rb

Overview

Central module for controlling ASCII vs Unicode (fancy) output.

This module provides:

  • Mode resolution (:default -> :fancy or :ascii based on output encoding)
  • Character sets for table borders (Unicode box-drawing vs ASCII)
  • Text conversion for ensuring ASCII-only output when needed

Usage:

mode = OutputChars.resolve_mode(:default)  # => :fancy or :ascii
charset = OutputChars.charset_for(mode)    # => hash of border chars
text = OutputChars.convert("café", mode)   # => "caf?" in :ascii mode

Constant Summary collapse

MODES =

Valid output character modes

%i[default fancy ascii].freeze
UNICODE_CHARSET =

Unicode box-drawing characters (fancy mode)

{
  top_left:     "\u250C",
  top_right:    "\u2510",
  bottom_left:  "\u2514",
  bottom_right: "\u2518",
  horizontal:   "\u2500",
  vertical:     "\u2502",
  top_tee:      "\u252C",
  bottom_tee:   "\u2534",
  left_tee:     "\u251C",
  right_tee:    "\u2524",
  cross:        "\u253C",
}.freeze
ASCII_CHARSET =

ASCII characters for table borders (ascii mode)

{
  top_left:     '+',
  top_right:    '+',
  bottom_left:  '+',
  bottom_right: '+',
  horizontal:   '-',
  vertical:     '|',
  top_tee:      '+',
  bottom_tee:   '+',
  left_tee:     '+',
  right_tee:    '+',
  cross:        '+',
}.freeze
TRANSLITERATIONS =

Common character transliterations to ASCII. This covers common accented characters and symbols users might encounter. Box-drawing characters are not included here; they're handled by charset_for.

{
  # Accented vowels
  'á' => 'a', 'à' => 'a', 'â' => 'a', 'ä' => 'a', 'ã' => 'a', 'å' => 'a',
  'Á' => 'A', 'À' => 'A', 'Â' => 'A', 'Ä' => 'A', 'Ã' => 'A', 'Å' => 'A',
  'é' => 'e', 'è' => 'e', 'ê' => 'e', 'ë' => 'e',
  'É' => 'E', 'È' => 'E', 'Ê' => 'E', 'Ë' => 'E',
  'í' => 'i', 'ì' => 'i', 'î' => 'i', 'ï' => 'i',
  'Í' => 'I', 'Ì' => 'I', 'Î' => 'I', 'Ï' => 'I',
  'ó' => 'o', 'ò' => 'o', 'ô' => 'o', 'ö' => 'o', 'õ' => 'o', 'ø' => 'o',
  'Ó' => 'O', 'Ò' => 'O', 'Ô' => 'O', 'Ö' => 'O', 'Õ' => 'O', 'Ø' => 'O',
  'ú' => 'u', 'ù' => 'u', 'û' => 'u', 'ü' => 'u',
  'Ú' => 'U', 'Ù' => 'U', 'Û' => 'U', 'Ü' => 'U',
  # Other common characters
  'ñ' => 'n', 'Ñ' => 'N',
  'ç' => 'c', 'Ç' => 'C',
  'ß' => 'ss',
  'æ' => 'ae', 'Æ' => 'AE',
  'œ' => 'oe', 'Œ' => 'OE',
  # Common symbols
  "\u20AC" => 'EUR', "\u00A3" => 'GBP', "\u00A5" => 'JPY',
  "\u00A9" => '(c)', "\u00AE" => '(R)', "\u2122" => '(TM)',
  "\u00B0" => 'deg',
  "\u2026" => '...',
  "\u2018" => "'", "\u2019" => "'", "\u201C" => '"', "\u201D" => '"',
  "\u2013" => '-', "\u2014" => '--',
  "\u00D7" => 'x', "\u00F7" => '/',
  "\u2264" => '<=', "\u2265" => '>=', "\u2260" => '!=',
  "\u2192" => '->', "\u2190" => '<-', "\u2194" => '<->',
  "\u2713" => '[x]', "\u2717" => '[ ]', "\u2714" => '[x]', "\u2718" => '[ ]',
  # Bullets and list markers
  "\u2022" => '*', "\u25E6" => 'o', "\u25AA" => '-', "\u25B8" => '>',
  # Box-drawing (for any stray usage outside tables)
  "\u250C" => '+', "\u2510" => '+', "\u2514" => '+', "\u2518" => '+',
  "\u2500" => '-', "\u2502" => '|',
  "\u252C" => '+', "\u2534" => '+', "\u251C" => '+', "\u2524" => '+', "\u253C" => '+'
}.freeze

Class Method Summary collapse

Class Method Details

.ascii_mode?(mode, io: $stdout) ⇒ Boolean

Checks if output should be ASCII-only for the given mode.

Parameters:

  • mode (Symbol) —

    :fancy, :ascii, or :default

  • io (IO) (defaults to: $stdout) —

    The output stream for resolving :default (default: $stdout)

Returns:

  • (Boolean) —

    true if ASCII-only output is required



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# File 'lib/cov_loupe/output_chars.rb', line 100

def ascii_mode?(mode, io: $stdout)
  resolved = mode == :default ? resolve_mode(mode, io: io) : mode
  resolved == :ascii
end

.charset_for(mode) ⇒ Hash

Returns the character set hash for the given mode.

Parameters:

  • mode (Symbol) —

    :fancy or :ascii (use resolve_mode first if :default)

Returns:

  • (Hash) —

    Character set with keys like :top_left, :horizontal, etc.



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# File 'lib/cov_loupe/output_chars.rb', line 69

def charset_for(mode)
  case mode
  when :fancy then UNICODE_CHARSET
  when :ascii then ASCII_CHARSET
  when :default then charset_for(resolve_mode(:default))
  else
    raise ArgumentError, "Invalid output_chars mode: #{mode.inspect}"
  end
end

.convert(text, mode, io: $stdout) ⇒ String

Converts text to ASCII-only when in :ascii mode. In :fancy mode, returns text unchanged.

Parameters:

  • text (String) —

    The text to convert

  • mode (Symbol) —

    :fancy, :ascii, or :default

  • io (IO) (defaults to: $stdout) —

    The output stream for resolving :default (default: $stdout)

Returns:

  • (String) —

    Original text (:fancy) or ASCII-only text (:ascii)



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# File 'lib/cov_loupe/output_chars.rb', line 86

def convert(text, mode, io: $stdout)
  return text if text.nil?

  resolved = mode == :default ? resolve_mode(mode, io: io) : mode
  return text if resolved == :fancy

  to_ascii(text)
end

.resolve_mode(mode, io: $stdout) ⇒ Symbol

Resolves :default mode to :fancy or :ascii based on output encoding.

Parameters:

  • mode (Symbol) —

    One of :default, :fancy, or :ascii

  • io (IO) (defaults to: $stdout) —

    The output stream to check encoding for (default: $stdout)

Returns:

  • (Symbol) —

    :fancy or :ascii



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# File 'lib/cov_loupe/output_chars.rb', line 55

def resolve_mode(mode, io: $stdout)
  case mode
  when :fancy then :fancy
  when :ascii then :ascii
  when :default then default_mode_for(io)
  else
    raise ArgumentError, "Invalid output_chars mode: #{mode.inspect}"
  end
end