Module: RedQuilt::Blockquote

Defined in:
lib/red_quilt/blockquote.rb

Overview

CommonMark spec 5.1 blockquotes.

Module-level functions are stateless helpers used by BlockParser's predicate dispatch. Blockquote::Parser is a cached collaborator created once in BlockParser#initialize and reused for every blockquote (including nested ones) — per-call state lives in method locals so reentrant #parse calls are safe.

Defined Under Namespace

Classes: Parser

Constant Summary collapse

BLOCKQUOTE_PREFIX_RE = 
/\A {0,3}>/

Class Method Summary collapse

Class Method Details

.marker_offset(text) ⇒ Object

Byte offset of the > within the line, or nil when there is no prefix. Only spaces may precede it (at most 3), so the character index returned by the match doubles as a byte offset.



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# File 'lib/red_quilt/blockquote.rb', line 23

def marker_offset(text)
  match = BLOCKQUOTE_PREFIX_RE.match(text)
  match && (match.end(0) - 1)
end

.match?(text) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/red_quilt/blockquote.rb', line 16

def match?(text)
  text.match?(BLOCKQUOTE_PREFIX_RE)
end

.strip_prefix(line) ⇒ Object

Strip the leading > (and at most one column of whitespace after it) from a blockquote line. Returns a new Line whose content is the inner text. If the line has no > prefix, the original line is returned unchanged (wrapped in a fresh Line so the caller treats it uniformly).



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# File 'lib/red_quilt/blockquote.rb', line 33

def strip_prefix(line)
  content = line.content
  bytes = content.bytesize
  i = 0
  abs_col = 0
  # Up to 3 spaces of indent before `>`.
  while i < 3 && i < bytes && content.getbyte(i) == 0x20
    i += 1
    abs_col += 1
  end
  unless i < bytes && content.getbyte(i) == 0x3E
    return Line.new(content, line.start_byte, line.end_byte, !content.match?(/\S/))
  end

  i += 1
  abs_col += 1 # consume `>`

  # Count column width of leading whitespace after `>` using
  # absolute-column tracking so a tab right after `>` (at col 1) is
  # correctly billed as only 3 columns of indent, not 4.
  ws_start_col = abs_col
  j = i
  while j < bytes
    b = content.getbyte(j)
    if b == 0x20
      abs_col += 1
    elsif b == 0x09
      abs_col = ((abs_col / 4) + 1) * 4
    else
      break
    end
    j += 1
  end
  ws_cols = abs_col - ws_start_col

  if ws_cols >= 1
    tail = (" " * (ws_cols - 1)) + content.byteslice(j..)
    offset = j
  else
    tail = content.byteslice(i..)
    offset = i
  end

  Line.new(tail, line.start_byte + offset, line.end_byte, !tail.match?(/\S/))
end