stream-any.js

// any : ( Stream a, a -> aBoolean ) -> Promise Boolean
Stream.prototype.any = function(pred)  {

  return  this.isEmpty ? Promise.resolve(false) 
        : this.isAbort ? Promise.reject(this.err) 
        : this.isCons  ? 
            (pred(this.head) ? Promise.resolve(true) : this.tail.any(pred) ) 
        : /* isFuture */ 
            this.promise.then( s => s.any(pred) );
}