function wrap(val, ch) {
  if (ch === '|') {
    return '(' + val.join(ch) + ')';
  }

  if (ch === ',') {
    return '{' + val.join(ch) + '}';
  }

  if (ch === '-') {
    return '[' + val.join(ch) + ']';
  }

  if (ch === '\\') {
    return '\\{' + val + '\\}';
  }
}
Wrap a value with parens, brackets or braces,
based on the given character/separator.

@param  {String|Array} `val`
@param  {String} `ch`
@return {String}