vitus points out the very cool instance of Monoid for Ordering. If you combine it with the instance instance Monoid b => Monoid (a -> b) it turns out your composition function is just (get ready): mappend Check it out: Prelude Data.Monoid> let f a b = EQ Prelude Data.Monoid> let g a b = … Read more
When the Closure used by sort has two parameters, it acts like a traditional Comparator. That is, for each comparison that is done during the sort, between two elements a and b, it returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the … Read more
You can ask ES to sort the results via the s (sort) searchParameter using s=i or s=index curl “localhost:9200/_cat/indices?pretty&s=i” curl “localhost:9200/_cat/aliases?pretty&s=index” To see the column’s headers, add “&v” : curl “localhost:9200/_cat/indices?pretty&v&s=index”`. You can find some explanations in the cat/indices documentation
Data in an array can be rearranged into a heap, in place. The algorithm for this is actually surprisingly simple., but I won’t go into it here. For a heap sort, you arrange the data so that it forms a heap in place, with the smallest element at the back (std::make_heap). Then you swap the … Read more
Use -n in your sort command, so that it sorts numerically. Also -r allows you to reverse the result: $ sort test.txt | uniq -c | sort -n 1 ada 1 ccd 1 cd 1 nnaa 2 aaa 2 bbb 4 aa 10 naa $ sort test.txt | uniq -c | sort -nr 10 naa … Read more
You can use these functions from the kotlin.comparisons package: fun <T: Comparable<T>> nullsLast(): Comparator<T?>, which constructs a comparator of something comparable that just puts nulls after all not-null values; fun <T, K> compareBy(comparator: Comparator<in K>, selector: (T) -> K): Comparator<T>, which accepts a comparator and a function that provides values for the comparator, combining them … Read more
The sorting usually should be done before collect() is called since that returns the dataset to the driver program and also that is the way an hadoop map-reduce job would be programmed in java so that the final output you want is written (typically) to HDFS. With the spark API this approach provides the flexibility … Read more
For ascending var nlist = [1, 6, 8, 2, 16, 0] nlist.sort((a, b) => a.compareTo(b)); For descending var nlist = [1, 6, 8, 2, 16, 0] nlist.sort((b, a) => a.compareTo(b));
It is true that there is no dead-simple answer. There are several patterns however. http://wiki.apache.org/couchdb/View_Snippets#Retrieve_the_top_N_tags. I do not personally like this because they acknowledge that it is a brittle solution, and the code is not relaxing-looking. Avi’s answer, which is to sort in-memory in your application. couchdb-lucene which it seems everybody finds themselves needing eventually! … Read more
You can try this def index @books = Book.order_by(created_at: :desc) end it works fine.