Questions about Ruby, dynamic, reflective, general-purpose object-oriented programming language that combines syntax inspired by Perl with Smalltalk-like features.
-6
votes
0answers
24 views
Running ruby commands does nothing [on hold]
When I attempt to run
rails _4.2.2_ new hello_app
I get
Failed to load /home/wesley/.gemrc because it doesn't contain valid YAML hash
Furthermore it doesn't generate anything at all. Like I ...
1
vote
3answers
147 views
Using multiple languages
I currently have a website running PHP laravel. We came to a point where we want to add a user-backend -- where users sign-up and can access functions when logging in.
My question is; Is it possible ...
2
votes
1answer
122 views
How to implement a (truly) global variable in a Rails app
How can I best implement a global counter in a Rails API app? (A central component in a system with several.)
Basically I have a transaction id I need to increment and roll over past a maximum value. ...
0
votes
1answer
54 views
Ruby: Abusing mixin
I'm currently working with some code that IMO has abused ruby's mixin features. Given that I'm new to ruby, I wonder if MO in IMO is correct or not.
My primary question is what makes more sense (and ...
2
votes
1answer
70 views
How do I go about setting up my Sinatra REST API on a server?
I'm an iOS developer primarily. In building my current app, I needed a server that would have a REST API with a couple of GET requests. I spent a little time learning Ruby, and landed on using ...
9
votes
1answer
217 views
Python's join seems to focus not on the items to join, but on the symbol, as compared to Ruby or Smalltalk, for a design reason?
I thought one of the cornerstone of OOP is that, we have objects, which are the items we are interested in dealing with, and then we send messages to them.
So it may seem natural that, I have a ...
6
votes
1answer
122 views
Testing procedural code
TL;DR. Writing procedural code within a DB transaction. How can I improve design of the code so it's better testable?
In my application I have a service object that perform multiple things within the ...
0
votes
2answers
70 views
Using symbols instead of strings in conditions
I usually have if/else conditions which involves comparing values with a constant string.
Is it really advantageous to use symbols in such cases or use string.
For eg.
if status == 'submitted'
...
...
5
votes
4answers
181 views
Ruby: if variable vs if variable.nil?
I'm new to Ruby and I was surprised when I found out that all objects are true apart from nil and false. Even 0 is true.
A nice thing about that property of the language is that you can write:
if ...
0
votes
1answer
71 views
Does extending a ruby class violate the LSP?
I am reading about SOLID principles. In Ruby tutorials and code samples, I often see subclass extensions like:
class House
attr_reader :items
end
class Room < House
attr_reader :chair
end
p ...
0
votes
0answers
68 views
Ruby best practices for Data Access layers
I'm starting my way into Ruby development and have some questions that I hope you can give your best opinion to better design some command line applications I'm developing.
What are the best patterns ...
5
votes
2answers
409 views
How are scripting languages compiled?
I know the term "scripting languages" is just a subset of programming languages, but I want to refer to programming languages such as Python and Ruby among others.
First of all, why don't we need a ...
0
votes
0answers
53 views
Add-on hot deployable modules for Akka actors?
I'm trying to build a small spray io - akka distributed application targeted towards smaller devices like the Raspberry Pi and BeagleBone Black.
The aim is to be able to talk to other devices that ...
1
vote
0answers
65 views
Where did the tradition of new releases on Christmas Day start? [closed]
Perl 6 is being released on Christmas Day this year. I'm familiar with Ruby having a history of releases on Christmas Day, going back as far as Ruby 1.0 in 1996 if not further. However, a quick scan ...
1
vote
0answers
77 views
Terminology - Difference between thread and process and how they manage DB connections
I've been working more with concurrency in Ruby recently, and I keep seeing various articles using "threads" and "process" interchangeably.
What are the actual definitions of these terms? Is a ...
2
votes
1answer
279 views
Android App with Ruby Backend Server
I'm working on a personal project to help me branch out and learn some new/different technologies. I'm a .NET programmer but I want to learn Ruby and how to develop Android apps. I have developed ...
0
votes
1answer
194 views
Best way to design a database interface [duplicate]
This is my situation
I have a website, mobile client and desktop client.
They can all pretty much do the same operations (website might be able to do more now but in the future they might have the ...
1
vote
0answers
136 views
Securing a private API used by an iOS App
I have an app that uses an API server and I do not want to have anything other than it to be able to use that API. I know this isn't totally possible, but I want to do what I can.
I don't think my ...
-2
votes
1answer
215 views
Why is Ruby's interpreter so small? [closed]
I noticed that the filesize of Ruby's interpreter seems suspiciously small.
I would have expected /bin/dash to be the smallest of all, but is 20x larger than Ruby:
Interpreter Bytes
...
1
vote
2answers
635 views
Is the time complexity of a while loop with three pointers different than 3 nested for loops?
This program (written in ruby) finds the largest 3 numbers in an array (without sorting the array). It has a while loop with three pointers. My fist instinct, since there is only one loop is to say ...
0
votes
3answers
153 views
Would it be possible to create a language similar to Ruby/Python with static typing that had the speed/memory usage of a compiled C program? [closed]
One of the main drawbacks of Ruby/Python is performance. I understand that they are interpreted and C is compiled. (And there are things like JRuby which do JIT compilation with Ruby). But they never ...
10
votes
8answers
3k views
How do I design a subclass whose method contradicts its superclass? [duplicate]
How do I design a subclass whose method contradicts its superclass? Let's say we have this example:
# Example 1
class Scissor
def right_handed?
true
end
end
class LeftHandedScissor < ...
0
votes
0answers
40 views
Is listing Types in documentation a code smell
I'm documenting a ruby application and looking closely at YARD. I like the increased structure provided over RDoc, but I'm unsure about the Type declaration. In YARD, you can do something like
...
0
votes
2answers
110 views
Refactoring case-when statement [duplicate]
The Product model which can have 2 price tables. The method price calculates the price of the product based on product's price table which is defined by price_table field.
class Product < ...
2
votes
3answers
269 views
Which is the convention in Rails to perform calculations and display the results?
So I'm working on a personal project on Rails to learn more about this framework, and I wanted to add a feature in which the user choose a particular record from the view, and after some calculations ...
1
vote
4answers
502 views
What is the “correct” way to store functions in a database?
Note: Yes, I know that storing functions in databases should be punishable by law.
We are developing a financial web application using PostgreSQL, Sinatra and AngularJS. As you may have guessed, a ...
1
vote
3answers
87 views
Replace repeated timestamp with variable in tests
I have couple hundred tests and I work with date/time a lot. In some tests, I aim for output format, elsewhere, I check date ranges. Therefore, my tests have lots of these:
FactoryGirl.create(:foo, ...
1
vote
1answer
144 views
What's the best practice for adding a lot of attributes to a Rails model?
So, I'm building an API wrapper gem that works with Spree's Product model. The API provides extensive customization of the data you send to it. I would like a user of the gem to be able to take ...
0
votes
2answers
147 views
Ruby Terminology Question: Implicit Declaration or no declaration at all?
I have a question, because in most serious sources I read, all say the same No variable is ever declared in Ruby, but still I have doubts, because according to what I was taught in my university ...
2
votes
0answers
75 views
Writing a gem supporting compiled languages with Rake. How to test?
I want to create a gem that extends the functionality of Rake, creating commands for compiling .NET code.*
Basically, I want to be able to write a Rakefile like this:
desc "Build main executable"
...
-1
votes
1answer
121 views
Is obsolete to study older versions of Ruby and RoR? [closed]
I want to study Ruby and RoR for some things I'll have to make, but almost every book, videos or any kind of source I find is outated, where the most current book I could find (link here) is one of ...
0
votes
1answer
143 views
How can I write these services using SOLID and keep them easy to test?
I am trying to write a couple of classes using SOLID principles and having some trouble.
The problem is quite simple. I have an application that tracks leads. Leads are created when events are raised ...
1
vote
2answers
414 views
How does the consumer-producer solution work?
I'm only a beginner, and my book doesn't cover this subject. I have researched my problem and found that an implementation of the consumer-producer pattern is the ideal solution, and have Googled it, ...
2
votes
1answer
78 views
BloomFilter in ruby should have k hash functions
I am reading the Bloom Filter implementation written in ruby. It should have k hash functions, but it looks like the same hash function is being used with different seed values. Is this a common way ...
0
votes
1answer
55 views
What would be the return type of a cartesian product of a multiset
I am writing a Multiset in Ruby. The Union, Intersection operations where simple and return a MultiSet. But, I am not sure what the return type of the cartesian product should be, should I return an ...
3
votes
2answers
94 views
Is a guardfile part of the private developers environment or the public OSS project?
Let us say I have an open source project on github. Now I wish to include tools required to develop the project so others can easily contribute. It is hard for me to tell when these tools should be ...
1
vote
1answer
55 views
Create a collection with “average points” of N items from a pool with items of various points
Let's say I have a question pool to generate exams out of it. Each question contains a difficulty from 1 (hard) to 99 (easy). The questions are available in a hash / array (adapt to your favorite ...
1
vote
1answer
86 views
How do rails project know about rake tasks from other repositories
We have a rake task called db:sanity_check which exists in a 'core' repo.
Other repositories that we have also show this rake task.
But they do not define the rake task. It 'comes' from core'
How ...
1
vote
1answer
386 views
Should I use expect or should when writing RSpec specs? [closed]
Please can someone explain to me how I should go about deciding whether to use expect or should syntax for my rspec examples.
From my understanding we should no longer be using the 'should' syntax.
...
-1
votes
1answer
315 views
Unevenly distributed random number generation [duplicate]
Let's say I have to generate random number from 1 to 100, however, the probability of each number is not 1/100, but a predefined probability.
How to generate that number? I use Ruby/Python.
0
votes
1answer
80 views
Calculate which quantity packages to use based on quantity of bookings
In my app, many appointments can be booked for activities. Each activity has many price packages with a price and a quantity.
On showing the cart, I need to work out what combination of packages ...
1
vote
1answer
98 views
Ruby on Rails application interfacing with a Datamax barcode printer [closed]
I am trying to find a standalone way to interface with a Datamax M-Class Mark2 label printer through a Ruby on Rails application. I currently have a solution that is working, which i use javascript to ...
3
votes
0answers
260 views
Splitting up a Rails/Ruby app onto multiple servers
We recently moved a large application to two machines, both running the same codebase.
I. Machine A
Web server for public facing application
Receives web hook call backs from our ESP
Handles a ...
1
vote
0answers
278 views
Run RSpec from within a ruby script while refreshing all ruby configs etc
I'm working with a very large project with tons of established tests that include some reasonably complicated environment setups and what not. I've recently run into a situation testing some ...
9
votes
2answers
386 views
Why don't Python and Ruby make a distinction between declaring and assigning a value to variables?
Two of the most popular dynamically typed scripting languages, Python and Ruby, do not make a distinction in syntax between the declaration of a variable and assignation of a value to it.
That is in ...
34
votes
2answers
4k views
Do modern languages still use parser generators?
I was researching about the gcc compiler suite on wikipedia here, when this came up:
GCC started out using LALR parsers generated with Bison, but gradually switched to hand-written ...
0
votes
1answer
298 views
Refactoring a Single Rails Model with large methods & long join queries trying to do everything
I have a working Ruby on Rails Model that I suspect is inefficient, hard to maintain, and full of unnecessary SQL join queries. I want to optimize and refactor this Model (Quiz.rb) to comply with ...
3
votes
2answers
605 views
What kind of exception to ask for out of range arguments?
What type of exception should I throw?
I have a console class which describes rectangle of cells which a user can index by passing in a coordinate:
width, height = 80, 25
console = ...
1
vote
3answers
518 views
How can I rank teams based off of head to head wins/losses
I'm trying to write an algorithm (specifically in Ruby) that will rank teams based on their record against each other. If a team A and team B have won the same amount of games against each other, then ...
0
votes
1answer
181 views
Android -> Ruby Server Interface -> Mongodb
I've been wrecking my brain about this for a few days. I'll run my scenario by you and hopefully you can help me. In my head this is how it goes:
I have an Android App.
I want my Android App to make ...
