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;
  delete this.force;

  return this;
}
function lazyConsForce() {
  
  var val = this.tailFn();
  
  this.tailValue = Array.isArray(val) ? fromArray(val) : val;
  

  delete this.tail;
  delete this.force;

  return this;
}
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 ; delete this . force ; return this ; }
But when cons is created, it's overloaded with lazy ones Force tail to whnf.
But when cons is created it s overloaded with lazy ones Force tail to whnf .