nl_tokens: But when cons is created it s overloaded with lazy ones Force tail to whnf .
pl_tokens: function lazyConsForce ( ) { /* jshint validthis:true */ var val = this . tailFn ( ) ; /* eslint-disable no-use-before-define */ this . tailValue = Array . isArray ( val ) ? fromArray ( val ) : val ; /* eslint-enable no-use-before-define */ delete this . tail ; <mask> this . force ; return this ; }