nl_tokens: Escapes a string
pl_tokens: function escapeRegexString ( token ) { // taken from: https://github.com/sindresorhus/escape-string-regexp/blob/master/index.js const matchOperatorsRe = / [|\\{}()[\]^$+*?.] / g ; return token . update ( str => str . <mask> ( matchOperatorsRe , '\\$&' ) ) ; }