elixir ruby

Multiple ruby traversal folder code instances collected, ruby instances 1. traverse all files in the folder and output file names Copy codeThe Code is as follows:Def traverse_dir (file_path)If File. directory? File_pathDir. foreach (file_path) do | file |If file! = "." And file! = ".."Traverse_dir (file_path + "/" + file)EndEndElsePuts "File :#{ File. basename (file_path)}, Size: # {File. size (file_path )}

Ruby implements the active mail push trigger program, and ruby implements mail triggering After receiving the email, the mail server pushes the notification program. Is there any way to achieve this? 1. Client polling2. The server actively pushes data. First, familiarize yourself with the protocol for sending and receiving emails:Net: SMTP (send mail)Net: POP3 (receive mail)Net: IMAP (receive mail) There ar

Explain the code block object Proc in Ruby, and explain the ruby object proc. Proc object Proc is a block conversion object. There are four methods to create a Proc: Sample Code # Method 1 inc = Proc. new {| x + 1} inc. call (2) #=> 3 # method 2 inc = lambda {| x + 1} inc. call (2) #=> 3 # method 3 inc =-> (x) {x + 1} inc. call (2) #=> 3 # Method 4 inc = proc {| x + 1} inc. call (2) # => 3 In addition to th

Various sorting algorithms implemented by Ruby and Ruby Time Complexity: Average (n ^ 2) Bubble sortCopy codeThe Code is as follows:Def bubble_sort ()(A. size-2). downto (0) do | I |(0.. I). each do | j |A [j], a [j + 1] = a [j + 1], a [j] if a [j]> a [j + 1]EndEndReturnEnd Selection sortCopy codeThe Code is as follows:Def selection_sort ()B = []A. size. times do | I |Min = a. minB A. delete_at (a. index (m

Class methods and class extensions in Ruby object-oriented programming, ruby Object-Oriented Programming Class Method The essence of a class method is a single-piece method that lives in a single-piece class of this class. Three methods are defined: # Method 1 def MyClass. a_class_method; end # method 2 class MyClass def self. anther_class_method; endend # method 3 * class MyClass class The third method in

Ruby-based optimal binary search tree algorithm and ruby-based optimal binary search algorithm The pseudo code in the introduction to algorithms is rewritten, plus the constructor for the solution of the first question in the Introduction Class Exercises.Copy codeThe Code is as follows:# Encoding: UTF-8= BeginAuthor: xu jinDate: Nov 11,201 2Optimal Binary Search TreeTo find by using EditDistance algorithmRe

Comparison of class variables and instance variables in Ruby, ruby class variable instances 1. The class variable name starts with @. A Class variable is shared by all instance objects of the class. The instance variable name starts with @, and each instance object has its own different instance variables; 2. class variables must be initialized before use; otherwise, an error is reported during use. If the

Summary of loop statements in ruby and summary of ruby loop statements While (when ...) Loop 　 　 While Condition Statement 1; Statement 2; statement... End Single Row while LOOP (Statement 1; Statement 2; statement... ) While Condition Until (...) Loop Until condition = while not (condition) For... In Loop 　 　 For variable in obj

Matrix concatenation algorithm implemented by Ruby and ruby matrix concatenation Dynamic Planning solves the problem of matrix concatenation, generates matrix sequences randomly, and outputs results in the form of (A1 (A2A3) (A4A5. Code: #encoding: utf-8=beginauthor: xu jin, 4100213date: Oct 28, 2012MatrixChainto find an optimum order by using MatrixChain algorithmexample output:The given array is:[30, 35,

Simple implementation of the Bubble Sorting Algorithm and Ruby version, and the Bubble Sorting Algorithm ruby Algorithm principle: Compares adjacent elements. If the first is bigger than the second, exchange the two of them.Perform the same operation on each adjacent element, from the first to the last. At this point, the final element should be the largest number.Repeat the preceding steps for all elements

machineInitialization completeStart the environment execution vagrant Halt shutdown environment by executing vagrant up in the appropriate directory when usedOther points of attentionAfter successful initialization, a configuration file named Vagrantfile is generated in the appropriate directory, which can be set for network, memory size, and other content.This article is from the "7692323" blog, please be sure to keep this source http://7702323.blog.51cto.com/7692323/1596334Build a

A few Ruby tips and Ruby tips Sequential call of code blocksCopy codeThe Code is as follows:Def touch_downYield [3, 7]Puts "touchdown! "EndTouch_down do | (first_down, second_down) |Puts "# {first_down} yards on the run"Puts "# {second_down} yards passed"End=> "3 yards on the run"=> "7 yards passed"=> "Touchdown! " It mainly refers to the use of array in block Retrieve elements from arrayCopy codeThe Code i

Example of the use of hundreds of semicolons and literal values in Ruby: ruby percent Use % () (abbreviated as % Q) for a single line string that requires interpolation and embedding double quotation marks ). Multi-line string, preferably heredocs. # bad (no interpolation needed) %( Do not use % q for strings without 'and. Unless many characters need to be escaped, the normal string is more readable.

String processing in ruby is flexible. "ABC" [0] returns 97 as"ABC" [1] 98"ABC" [2] 99"ABC" [3] Nil"ABC" [-1] 99 forward number"ABC" [-2] 98"ABC" [-3] 97"ABC" [-4] Nil "ABC" * 2 returns "abcabc" supporting Multiplication "ABC" + "def" returns "abcdef" "Abcdef" [] "A" extracts one digit from the position 0"Abcdef" [1, 3] "BCD""Abcdef" [-3, 3] "def""Abcdef" [1 .. 3] "BC" from 1 to 3 Come to a riddleProgram Code highlighting produced by Acti

Arrays in ruby are created by square brackets. The initial values can be placed in square brackets and separated by commas. array elements can be of different types and support addition and multiplication. Ary = [1, 2, "3"]Ary * 2 Returns [1, 2, "3", 1, 2, "3"]Ary + ["Lee", "ho"] returns [1, 2, "3", "Lee", "ho"]Ary [] returns [1, 2] and obtains two elements starting from position 0.Ary [0 .. 2] returns [1, 2, "3"] From position 0 to position 2 Arr

I used to want to use Java for something similar. Today I see Ruby already has ----- Gem install Chardet-y ----- Require 'rubygems'Require 'universaldetector'Require 'net/http'Net: http. version_1_2Net: http. Start ('www .sina.com.cn ') {| HTTP |Data = http. Get ("/"). BodyP universaldetector: chardet (data)}It is a Python version transplant, and there is a confidence parameter. I tested several sites in China and it is very accurate. However,

inheritance of loading modules and classes: Module MdefPuts "' The ' method ' in module M"EndEnd Class CInclude MEnd Class D End obj = d.newObj.reportThe example method is defined in module M, the C class is mixed with module M, Class D is a subclass of Class C, and obj is an instance of Class D, the object of obj can call the method. From an object's perspective, suppose you are an object, someone sends you a message, you have to find a way to respond, and the idea is probably like this:

entities are destroyed Delete_all: All associated entities are deleted directly from the database, unrecoverable nullify: foreign keys are Set to NULL, unrecoverable restrict_with_exception: Throw exception hint Restrict_with_error: Throw error prompt 5, Foreign_key: Define column name for foreign Key 6, inverse_of : Indicates the inverse associated entity 7, Primary_key: Indicates the associated item ID 8, through: Indicates that a many-to-many relationship uses a third-party entity 9, validat

In the process of using ruby/rails, it is found that sometimes performance is unsatisfactory, such as the generation of a 3-layer tree with 600 items of the directory to spend 20ms, in order to improve performance in the learning to write Ruby module with C + +, the understanding of the Swig, Rubyinline a series of assistive tools that help you write C/A + + to improve