class Prism::Translation::Parser::Lexer

def escape_read(result, scanner, control, meta)
  if scanner.skip("\n")
    # Line continuation
  elsif (value = ESCAPES[scanner.peek(1)])
    # Simple single-character escape sequences like \n
    result.append_as_bytes(value)
    scanner.pos += 1
  elsif (value = scanner.scan(/[0-7]{1,3}/))
    # \nnn
    result.append_as_bytes(escape_build(value.to_i(8), control, meta))
  elsif (value = scanner.scan(/x[0-9a-fA-F]{1,2}/))
    # \xnn
    result.append_as_bytes(escape_build(value[1..].to_i(16), control, meta))
  elsif (value = scanner.scan(/u[0-9a-fA-F]{4}/))
    # \unnnn
    result.append_as_bytes(value[1..].hex.chr(Encoding::UTF_8))
  elsif scanner.skip("u{}")
    # https://github.com/whitequark/parser/issues/856
  elsif (value = scanner.scan(/u{.*?}/))
    # \u{nnnn ...}
    value[2..-2].split.each do |unicode|
      result.append_as_bytes(unicode.hex.chr(Encoding::UTF_8))
    end
  elsif (value = scanner.scan(/c\\?(?=[[:print:]])|C-\\?(?=[[:print:]])/))
    # \cx or \C-x where x is an ASCII printable character
    escape_read(result, scanner, true, meta)
  elsif (value = scanner.scan(/M-\\?(?=[[:print:]])/))
    # \M-x where x is an ASCII printable character
    escape_read(result, scanner, control, true)
  elsif (byte = scanner.get_byte)
    # Something else after an escape.
    if control && byte == "?"
      result.append_as_bytes(escape_build(0x7f, false, meta))
    else
      result.append_as_bytes(escape_build(byte.ord, control, meta))
    end
  end
end