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Module: Kward::ANSI

Defined in:
lib/kward/ansi.rb

Overview

ANSI SGR styling and terminal-text helpers.

Terminal control output sequences live in TerminalSequences, and input key sequences live in TerminalKeys. This module owns text-level concerns: colorizing strings, stripping/sanitizing escape sequences, visible wrapping, and lightweight Markdown rendering for terminal output.

Defined Under Namespace

Classes: MarkdownStream

Constant Summary collapse

SGR_PATTERN = 
/\e\[[0-9;:]*m/.freeze
STYLES = 
{
  reset: 0,
  bold: 1,
  dim: 2,
  italic: 3,
  strikethrough: 9,
  red: 31,
  green: 32,
  yellow: 33,
  blue: 34,
  magenta: 35,
  cyan: 36,
  gray: 90,
  grey: 90,
  white: 97,
  primary_green: "38;2;138;160;106",
  bright_accent_green: "38;2;155;255;0",
  augen: "38;2;155;255;0",
  dark_forest_green: "38;2;78;88;53",
  stone: "38;2;196;192;178",
  metal_dark: "38;2;42;42;42",
  background: "38;2;22;24;22"
}.freeze

Class Method Summary collapse

Class Method Details

.blockquote(text, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 259

def blockquote(text, enabled: enabled?)
  "#{colorize("│", :gray, enabled: enabled)} #{inline_markdown(text, enabled: enabled)}"
end

.colorize(text, *styles, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 47

def colorize(text, *styles, enabled: enabled?)
  string = text.to_s
  return string unless enabled

  codes = styles.flatten.map { |style| STYLES.fetch(style, style) }.compact
  return string if codes.empty?

  "\e[#{codes.join(";")}m#{string}\e[0m"
end

.disabled_color?(env) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kward/ansi.rb', line 320

def disabled_color?(env)
  return true if env.key?("NO_COLOR") && !env["NO_COLOR"].to_s.empty?
  return true if env["CLICOLOR"] == "0"

  env["TERM"] == "dumb"
end

.enabled?(output = $stdout, env: ENV) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kward/ansi.rb', line 37

def enabled?(output = $stdout, env: ENV)
  setting = env["KWARD_COLOR"].to_s.downcase
  return true if %w[always force forced true yes 1].include?(setting)
  return false if %w[never false no 0].include?(setting)
  return true if forced_color?(env)
  return false if disabled_color?(env)

  output.respond_to?(:tty?) && output.tty?
end

.escape_sequence_at(string, index) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 139

def escape_sequence_at(string, index)
  chunk = string[index..]
  chunk.match(/\A\e\][^\a]*(?:\a|\e\\)/m)&.[](0) ||
    chunk.match(/\A\e[P_X^][\s\S]*?\e\\/m)&.[](0) ||
    chunk.match(/\A\e\[[0-9;:?]*[ -\/]*[@-~]/)&.[](0) ||
    chunk[0, 2]
end

.forced_color?(env) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kward/ansi.rb', line 314

def forced_color?(env)
  force_color = env["FORCE_COLOR"]
  clicolor_force = env["CLICOLOR_FORCE"]
  (force_color && force_color != "0") || (clicolor_force && clicolor_force != "0")
end

.inline_bold(text, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 289

def inline_bold(text, enabled: enabled?)
  text.gsub(/\*\*([^\n]+?)\*\*/) do
    colorize(Regexp.last_match(1), :bold, enabled: enabled)
  end
end

.inline_code(line, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 310

def inline_code(line, enabled: enabled?)
  inline_markdown(line, enabled: enabled)
end

.inline_emphasis(text, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 283

def inline_emphasis(text, enabled: enabled?)
  rendered = inline_bold(text, enabled: enabled)
  rendered = inline_strikethrough(rendered, enabled: enabled)
  inline_italic(rendered, enabled: enabled)
end

.inline_italic(text, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 301

def inline_italic(text, enabled: enabled?)
  rendered = text.gsub(/(^|[\s\(\[{])\*([^*\n]+?)\*(?=$|[\s\)\]},.!?:;])/) do
    "#{Regexp.last_match(1)}#{colorize(Regexp.last_match(2), :italic, enabled: enabled)}"
  end
  rendered.gsub(/(^|[\s\(\[{])_([^_\n]+?)_(?=$|[\s\)\]},.!?:;])/) do
    "#{Regexp.last_match(1)}#{colorize(Regexp.last_match(2), :italic, enabled: enabled)}"
  end
end

.inline_links(text, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 273

def inline_links(text, enabled: enabled?)
  text.split(/(\[[^\n\]]+\]\([^)\s]+\))/).map do |part|
    if (match = part.match(/\A\[([^\n\]]+)\]\(([^)\s]+)\)\z/))
      "#{colorize(match[1], :cyan, enabled: enabled)} (#{colorize(match[2], :dim, enabled: enabled)})"
    else
      inline_emphasis(part, enabled: enabled)
    end
  end.join
end

.inline_markdown(line, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 263

def inline_markdown(line, enabled: enabled?)
  line.to_s.split(/(`[^`\n]+`)/).map do |part|
    if part.start_with?("`") && part.end_with?("`") && part.length > 1
      "`#{colorize(part[1...-1], :dim, enabled: enabled)}`"
    else
      inline_links(part, enabled: enabled)
    end
  end.join
end

.inline_strikethrough(text, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 295

def inline_strikethrough(text, enabled: enabled?)
  text.gsub(/~~([^\n]+?)~~/) do
    colorize(Regexp.last_match(1), :strikethrough, enabled: enabled)
  end
end

.markdown(text, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 147

def markdown(text, enabled: enabled?)
  string = text.to_s
  lines = string.lines(chomp: true)
  rendered = []
  in_fence = false

  lines.each do |line|
    if (match = line.match(/\A\s*```([^`]*)\s*\z/))
      if in_fence
        rendered << colorize("└" + "─" * 39, :gray, enabled: enabled)
        in_fence = false
      else
        language = match[1].to_s.strip
        label = language.empty? ? "code" : "code #{language}"
        rendered << colorize("┌─ #{label}", :gray, enabled: enabled)
        in_fence = true
      end
      next
    end

    if in_fence
      rendered << colorize("│ #{line}", :dim, enabled: enabled)
    else
      rendered << markdown_line(line, enabled: enabled)
    end
  end

  rendered << colorize("└" + "─" * 39, :gray, enabled: enabled) if in_fence
  rendered.join("\n") + (string.end_with?("\n") ? "\n" : "")
end

.markdown_heading(marker, text, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 249

def markdown_heading(marker, text, enabled: enabled?)
  "#{marker}#{colorize(text, :bold, enabled: enabled)}"
end

.markdown_line(line, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 237

def markdown_line(line, enabled: enabled?)
  if (match = line.match(/\A(\#{1,6}\s+)(.+)\z/))
    markdown_heading(match[1], match[2], enabled: enabled)
  elsif (match = line.match(/\A(\s*)[-*]\s+\[([ xX])\]\s+(.+)\z/))
    task_list_item(match[1], match[2], match[3], enabled: enabled)
  elsif (match = line.match(/\A>\s?(.*)\z/))
    blockquote(match[1], enabled: enabled)
  else
    inline_markdown(line, enabled: enabled)
  end
end

.normalize_transcript_encoding(text) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 79

def normalize_transcript_encoding(text)
  string = text.to_s.dup
  return string unless string.encoding == Encoding::ASCII_8BIT

  string.force_encoding(Encoding::UTF_8)
  string.valid_encoding? ? string : string.scrub
end

.sanitize_transcript(text) ⇒ Object

Drops unsafe terminal controls from transcript text while preserving SGR color.



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# File 'lib/kward/ansi.rb', line 69

def sanitize_transcript(text)
  scan_escape_tokens(normalize_transcript_encoding(text)).each_with_object(+"") do |token, sanitized|
    if token[:escape]
      sanitized << token[:text] if token[:text].match?(SGR_PATTERN)
    else
      sanitized << token[:text]
    end
  end
end

.scan_escape_tokens(text) ⇒ Object

Splits text into visible chunks and terminal escape sequence chunks.



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# File 'lib/kward/ansi.rb', line 121

def scan_escape_tokens(text)
  string = text.to_s
  tokens = []
  index = 0
  while index < string.length
    if string[index] == "\e" && (escape = escape_sequence_at(string, index))
      tokens << { text: escape, escape: true }
      index += escape.length
      next
    end

    next_escape = string.index("\e", index) || string.length
    tokens << { text: string[index...next_escape], escape: false } if next_escape > index
    index = next_escape
  end
  tokens
end

.strip(text) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 57

def strip(text)
  strip_control_sequences(text)
end

.strip_control_sequences(text) ⇒ Object

Removes terminal escape/control sequences while preserving visible text.



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# File 'lib/kward/ansi.rb', line 62

def strip_control_sequences(text)
  scan_escape_tokens(text).each_with_object(+"") do |token, stripped|
    stripped << token[:text] unless token[:escape]
  end
end

.task_list_item(indent, marker, text, enabled: enabled?) ) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 253

def task_list_item(indent, marker, text, enabled: enabled?)
  checked = marker.downcase == "x"
  box = checked ? colorize("☑", :green, enabled: enabled) : colorize("☐", :gray, enabled: enabled)
  "#{indent}#{box} #{inline_markdown(text, enabled: enabled)}"
end

.wrap_visible(text, width) ⇒ Object 



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# File 'lib/kward/ansi.rb', line 87

def wrap_visible(text, width)
  line_width = [width.to_i, 1].max
  rows = []
  current = +""
  visible_width = 0

  scan_escape_tokens(text).each do |token|
    if token[:escape]
      next unless token[:text].match?(SGR_PATTERN)

      if current.empty? && rows.any?
        rows[-1] << token[:text]
      else
        current << token[:text]
      end
      next
    end

    token[:text].each_char do |char|
      current << char
      visible_width += 1
      if visible_width >= line_width
        rows << current
        current = +""
        visible_width = 0
      end
    end
  end

  rows << current unless current.empty?
  rows
end