Tutorial by Examples: c

Introduction

Trees are a sub-type of the more general node-edge graph data structure. To be a tree, a graph must satisfy two requirements: It is acyclic. It contains no cycles (or "loops"). It is connected. For any given node in the graph, every node is reachable. All nodes are reachable throug...

algorithm • Trees

Launch the REPL

After installing Julia, to launch the read-eval-print-loop (REPL): On Unix Systems Open a terminal window, then type julia at the prompt, then hit Return. You should see something like this come up: On Windows Find the Julia program in your start menu, and click it. The REPL should be launched...

Julia Language • REPL

Using the REPL as a Calculator

The Julia REPL is an excellent calculator. We can start with some simple operations: julia> 1 + 1 2 julia> 8 * 8 64 julia> 9 ^ 2 81 The ans variable contains the result of the last calculation: julia> 4 + 9 13 julia> ans + 9 22 We can define our own variables usi...

Julia Language • REPL

Relationship Convention

Code First infer the relationship between the two entities using navigation property. This navigation property can be a simple reference type or collection type. For example, we defined Standard navigation property in Student class and ICollection navigation property in Standard class. So, Code Firs...

Entity Framework • Code First Conventions

Numbering the nodes of a tree with a counter

We have a tree data type like this: data Tree a = Tree a [Tree a] deriving Show And we wish to write a function that assigns a number to each node of the tree, from an incrementing counter: tag :: Tree a -> Tree (a, Int) The long way First we'll do it the long way around, since it illust...

Haskell Language • State Monad

Old Doctypes

HTML 3.2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> HTML 3.2 is well supported by most browsers in use. However, HTML 3.2 has limited support for style sheets and no support for HTML 4 features such as frames and internationalization. HTML 2.0 <!DOCTYPE HTML P...

HTML • Doctypes

Converting All Tables in one Database

To easily convert all tables in one database, use the following: SET @DB_NAME = DATABASE(); SELECT CONCAT('ALTER TABLE `', table_name, '` ENGINE=InnoDB;') AS sql_statements FROM information_schema.tables WHERE table_schema = @DB_NAME AND `ENGINE` = 'MyISAM' AND `TABLE_TYPE` = '...

MySQL • Converting from MyISAM to InnoDB

Configuration

Manage Roles Global Roles- Create roles with selected set of Jenkins features e.g. Usually for a development project, 2 roles can be created. Developer- Global role can be set to only Overall : Read ProjectOwner- Global role can be set to Overall : Read This restricts developer and project ...

jenkins • Role Strategy Plugin

Bi-Directional Many to Many using user managed join table object

@Entity @Table(name="FOO") public class Foo { private UUID fooId; @OneToMany(mappedBy = "bar") private List<FooBar> bars; } @Entity @Table(name="BAR") public class Bar { private UUID barId; @OneToMany(mappedBy = "f...

hibernate • Hibernate Entity Relationships using Annotations

Bi-Directional Many to Many using Hibernate managed join table

@Entity @Table(name="FOO") public class Foo { private UUID fooId; @OneToMany @JoinTable(name="FOO_BAR", joinColumns = @JoinColumn(name="fooId"), inverseJoinColumns = @JoinColumn(name="barId")) private List<Bar&g...

hibernate • Hibernate Entity Relationships using Annotations

Bi-directional One to Many Relationship using foreign key mapping

@Entity @Table(name="FOO") public class Foo { private UUID fooId; @OneToMany(mappedBy = "bar") private List<Bar> bars; } @Entity @Table(name="BAR") public class Bar { private UUID barId; @ManyToOne @JoinColumn(nam...

hibernate • Hibernate Entity Relationships using Annotations

Bi-Directional One to One Relationship managed by Foo.class

@Entity @Table(name="FOO") public class Foo { private UUID fooId; @OneToOne(cascade = CascadeType.ALL) @JoinColumn(name = "barId") private Bar bar; } @Entity @Table(name="BAR") public class Bar { private UUID barId; ...

hibernate • Hibernate Entity Relationships using Annotations

Uni-Directional One to Many Relationship using user managed join table

@Entity @Table(name="FOO") public class Foo { private UUID fooId; @OneToMany @JoinTable(name="FOO_BAR", joinColumns = @JoinColumn(name="fooId"), inverseJoinColumns = @JoinColumn(name="barId", unique=true)) private ...

hibernate • Hibernate Entity Relationships using Annotations

Uni-directional One to One Relationship

@Entity @Table(name="FOO") public class Foo { private UUID fooId; @OneToOne private Bar bar; } @Entity @Table(name="BAR") public class Bar { private UUID barId; //No corresponding mapping to Foo.class } Specifies a one-way relationship b...

hibernate • Hibernate Entity Relationships using Annotations

TestScheduler

TestSchedulers allows you to control time and execution of Observables instead of having to do busy waits, joining threads or anything to manipulate system time. This is VERY important if you want to write unit tests that are predictable, consistent and fast. Because you are manipulating time, the...

rx-java • Unit Testing

http and https redirects and HSTS configuration

Generic redirect to https: # Enable Rewrite engine RewriteEngine on # Check if URL does not contain https RewriteCond %{HTTPS} off [NC] # If condition is true, redirect to https RewriteRule (.*) https://%{SERVER_NAME}/$1 [R=301,L] Generic redirect to http: # Enable Rewrite engine Rewr...

Hypertext Access file • Rewriting and Redirecting

Register Events inside the Listener class

import org.bukkit.event.Listener; import org.bukkit.event.EventHandler; import org.bukkit.event.EventPriority; import org.bukkit.event.player.PlayerLoginEvent; import org.bukkit.event.player.PlayerQuitEvent; public class MyEventListener implements Listener { /** * Constructor ...

bukkit • Event Handling

Using mod_rewrite in the static configuration file

Add the following directive before using any other mod_rewrite directive (RewriteRule, RewriteCond, RewriteBase or RewriteMap). RewriteEngine on By default the engine is turned off. mod_rewrite directives found while the engine is turned off are ignored. Enable it from within the virtual host co...

mod-rewrite • Getting started with mod-rewrite

Using mod_rewrite from the dynamic configuration files

Important: Using the dynamic configuration files (.htaccess) is a big performance hit. When you have access to the static configuration file (httpd.conf or something similar) you should use that instead. In the static configuration file, allow dynamic configuration files to override "Filei...

mod-rewrite • Getting started with mod-rewrite

Initialize serial device

import serial #Serial takes these two parameters: serial device and baudrate ser = serial.Serial('/dev/ttyUSB0', 9600)

Python Language • Python Serial Communication (pyserial)