Function escape

src/utils.js:119–165

(string)

}

function escape(string) {
  let output = "";
  let counter = 0;

  while (counter < string.length) {
    // eslint-disable-next-line no-plusplus
    const character = string.charAt(counter++);

    let value;

    // eslint-disable-next-line no-control-regex
    if (/[\t\n\f\r\x0B]/.test(character)) {
      const codePoint = character.charCodeAt();

      value = `\\${codePoint.toString(16).toUpperCase()} `;
    } else if (character === "\\" || regexSingleEscape.test(character)) {
      value = `\\${character}`;
    } else {
      value = character;
    }

    output += value;
  }

  const firstChar = string.charAt(0);

  if (/^-[-\d]/.test(output)) {
    output = `\\-${output.slice(1)}`;
  } else if (/\d/.test(firstChar)) {
    output = `\\3${firstChar} ${output.slice(1)}`;
  }

  // Remove spaces after `\HEX` escapes that are not followed by a hex digit,
  // since they’re redundant. Note that this is only possible if the escape
  // sequence isn’t preceded by an odd number of backslashes.
  output = output.replace(regexExcessiveSpaces, ($0, $1, $2) => {
    if ($1 && $1.length % 2) {
      // It’s not safe to remove the space, so don’t.
      return $0;
    }

    // Strip the space.
    return ($1 || "") + $2;
  });

  return output;
}

function gobbleHex(str) {
  const lower = str.toLowerCase();