Questions tagged [design-patterns]

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6 votes
1 answer

Is there a way of objectively measuring the efficiency or quality of software or code design?

I've been thinking about ways of measuring code, and, quite frankly, I can't think of truly objective, semi-universal ways of evaluating the quality or "strength" of code to say, "Yes, this is better ...
CinchBlue's user avatar
  • 594
5 votes
2 answers

Is there one (or a few) canonical/ specific use cases for "functions returning functions" (beyond "decorators")?

Is there one (or a few) canonical/ specific use cases for "functions returning functions" (beyond "decorators")? What can you do with "functions returning functions" ...
Serge Hulne's user avatar
4 votes
2 answers

What's the difference between declarative syntax and encapsulation?

I had been first introduced to the idea of declarative syntax when using Angular JS. From what I understand, the idea is that you say, "do this" instead of "in order to do this, do this, this and this"...
Adam Zerner's user avatar
3 votes
3 answers

Design patterns for simple text based scripting language?

In my current application I am trying to determine the best way to implement a simple scripting language. This language would allow a user to create a script that controls a machine with various ...
KDecker's user avatar
  • 343
3 votes
2 answers

Is there a formal term for functions that have static state across executions?

Two examples, one in PHP: function adder($i){ static $a = 0; $a += $i; return $a; } A similar effect can be achieved with closures in javascript: ...
Kit Sunde's user avatar
  • 131
1 vote
1 answer

design cache system using queuing theory

If we have data from a random population, a 3d histogram of throughput and current cache size of DRAM (intersection of a IOPS & a cache size will have a count). How can one use queuing theory to ...
bicepjai's user avatar
  • 111
1 vote
1 answer

What is the difference between a "meta model" and "design patterns"?

Where is the difference between a "meta model" and "design patterns"? If you take, for example, Fowlers "Identity Field" from his book "Patterns Of Enterprise Application Architecture": Why is this a ...
powerweb's user avatar
1 vote
1 answer

Reference request for book on design patterns with foreword by Christopher Alexander

I do recall having found a book on software design patterns with a foreword by Christopher Alexander. Now, as is well known Alexander is credited as the creator of the concept of design patterns and ...
Juan Meleiro's user avatar
1 vote
0 answers

system architecture or software architecture

I was trying to get started with a small project but I quickly realized I had to do more research on the subject. Suppose, when creating a site, in production, there's a certain structure how the ...
BumbleBee's user avatar
1 vote
0 answers

Building an architecture without pointers, objects, memory allocation or first class functions [closed]

Many sources for good software architecture will use objects, pointers, memory allocation in their solutions. The PLC programming language 61131-3 Structured Text is really limited in this regard, ...
krakers's user avatar
  • 11
1 vote
1 answer

Combine abstract factory with decorator pattern [closed]

I'm working on a simple project of software engineering that should combine two patterns. I choose Abstract Factory and Decorator patterns to modify (dynamically) objects created with the concrete ...
Duccio Bertieri's user avatar
0 votes
1 answer

How does this example violate Liskov substitution principle, which then causes violation of the open-closed principle?

From Agile Principles, Patterns, and Practices in C# by Robert Martin, Listing 10-1. A violation of LSP causing a violation of OCP ...
Tim's user avatar
  • 4,895
0 votes
1 answer

State Machine and State transition Table - Explanation and Creation Of

How do I create a state transition table/array in actual code/pseudo-code? I haven't experienced the "ah-ha" moment yet with the state machine to coding (and I really want to). I've looked at several ...
GisMofx's user avatar
  • 123
0 votes
0 answers

How to Think About Physical Design of Libraries in C++ When Considering the Deliverable's API?

Since design ideas, and even the concept of Physical Design (exactly where you put your files), are such a broad topic, may I give a definite example and ask for feedback on the example? Suppose you ...
tarstevs's user avatar
0 votes
0 answers

Clarification about a sentence from GoF Design Patterns book

I'm currently reading Design Patterns: Elements of Reusable Object-Oriented Software by GoF and having trouble understanding the following sentence (page 19, Section 1.6): Composition requires ...
Albert Huzejrovic's user avatar
0 votes
0 answers

When to dynamically compute data vs. when to use variables and update on demand?

Two scenarios: Function is called and data is computed and returned. Data is saved in variable, updated when required, data is retrieved from variable. So I was wondering in what kind of scenarios ...
Konstantin Schlegel's user avatar
0 votes
0 answers

Best way to code a shopping cart consisting of items with different properties

This is an interview question. Interviewer wanted a scalable solution Goal is to find value of shopping cart. Cart could have 3 different types of items(Physical,Digital,URL). Only Physical Items have ...
NoobScript's user avatar
0 votes
0 answers

What are the pros and cons of these two coding patterns/structures? And do they have a formal term?

I have traditionally been doing things like this: function test() // A { if (/* conditions */) return true; else return false; } Of late, ...
decidophobe's user avatar