nl_tokens: Internal method determining whether or not the provided arguments can be smashed or extended together based on types .
pl_tokens: function isExtendable ( ... args ) { // this is a fairly expensive call. find a way to optimize further?
   if ( args . length < 1 ) return false ; let baseType = typeForExtend ( args [ 0 ] ) ; if ( ! ( baseType === <mask> . array || baseType === types . object || baseType === types . set || baseType === types . map || baseType === types . function ) ) { return false ; } for ( let i = 1 ; i < args . length ; i ++ ) { let targetType = typeForExtend ( args [ i ] ) ; if ( targetType !== baseType ) return false ; } return true ; }