Tutorial by Examples: re

Elasticsearch is accessed through a HTTP REST API, typically using the cURL library. The messages between the search server and the client (your or your application) are sent in the form of JSON strings. By default, Elasticsearch runs on port 9200. In the examples below, ?pretty is added to tell El...

array_reduce reduces array into a single value. Basically, The array_reduce will go through every item with the result from last iteration and produce new value to the next iteration. Usage: array_reduce ($array, function($carry, $item){...}, $defaul_value_of_first_carry) $carry is the result f...

To get First object: MyModel.objects.first() To get last objects: MyModel.objects.last() Using Filter First object: MyModel.objects.filter(name='simple').first() Using Filter Last object: MyModel.objects.filter(name='simple').last()

A typeglob *foo holds references to the contents of global variables with that name: $foo, @foo, $foo, &foo, etc. You can access it like an hash and assign to manipulate the symbol tables directly (evil!). use v5.10; # necessary for say our $foo = "foo"; our $bar; say ref *foo{SCAL...

XE2 program CrossPlatformHelloWorld; uses FMX.Dialogs; {$R *.res} begin ShowMessage('Hello world!'); end. Most of the Delphi supported platforms (Win32/Win64/OSX32/Android32/iOS32/iOS64) also support a console so the WriteLn example fits them well. For the platforms that require...

When Intel designed the original x86, the 8086 (and 8088 derivative), they included Segmentation to allow the 16-bit processor to access more than 16 bits worth of address. They did this by making the 16-bit addresses be relative to a given 16-bit Segment Register, of which they defined four: Code S...

Related to Monads are F# computation expressions (CE). A programmer typically implements a CE to provide an alternative approach to chaining Monads, ie instead of this: let v = m >>= fun x -> n >>= fun y -> return_ (x, y) You can write this: let v = ce { let! x = m ...

The ]]> character sequence is not allowed in element content. The easiest way to escape it is to escape > as >. <?xml version="1.0"?> <document> The sequence ]]> cannot appear in element content. </document>

Characters can be escaped using character references, in element content or attribute values. Their Unicode codepoint can be specified in decimal or hex. <?xml version="1.0"?> <document> The line feed character can be escaped with a decimal (
) or hex (
) ...

Type abbreviations allow you to create aliases on existing types to give them a more meaningful senses. // Name is an alias for a string type Name = string // PhoneNumber is an alias for a string type PhoneNumber = string Then you can use the alias just as any other type: // Create a recor...

Suppose we want to get all product categories with total sales greater than 20. Here is a query without Common Table Expressions: SELECT category.description, sum(product.price) as total_sales FROM sale LEFT JOIN product on sale.product_id = product.id LEFT JOIN category on product.category_id ...

Suppose we want to query the "cheapest products" from the "top categories". Here is an example of query using Common Table Expressions -- all_sales: just a simple SELECT with all the needed JOINS WITH all_sales AS ( SELECT product.price as product_price, category.id a...

Objective c: //this is the dictionary you start with. NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:@"name1", @"Sam",@"name2", @"Sanju",nil]; //check if the dictionary contains the key you are going to modify. In this example, @&qu...

perl -ne'print if /foo/' file.txt Case-insensitive: perl -ne'print if /foo/i' file.txt

perl -pe"s/foo/bar/g" file.txt Or in-place: perl -i -pe's/foo/bar/g' file.txt On Windows: perl -i.bak -pe"s/foo/bar/g" file.txt

perl -0777 -ne'print "The whole file as a string: --->$_<---\n"' Note: The -0777 is just a convention. Any -0400 and above would de the same.

genRandom creates a stream of random numbers that has a one in four chance of terminating each time it's called. def genRandom: Stream[String] = { val random = scala.util.Random.nextFloat() println(s"Random value is: $random") if (random < 0.25) { Stream.empty[String] ...

curl -XGET 'http://www.example.com:9200/myIndexName/myTypeName/1' Output: { "_index" : "myIndexName", "_type" : "myTypeName", "_id" : "1", "_version" : 1, "found": true, "_source&qu...

curl -XPUT 'www.example.com:9200/myIndexName?pretty' Output: { "acknowledged" : true } Reference Link: Here

Let's say there's a collection called Todos and the autopublish package is added. Here is the basic component. import { createContainer } from 'meteor/react-meteor-data'; import React, { Component, PropTypes } from 'react'; import Todos from '/imports/collections/Todos'; export class List exte...