I'm doing some research on the benefits of OOP to convince my faculty (mechanical engineering) to adapt a more modern approach of software development.
Despite some intensive search, I can't find examples of successful, more or less well known projects that have been done completly OO.
I understand that many projects are mixed from c and c++ and that you can create "object based" architectures with c, but surely there must be some OO-only projects to support my argumentation.
It would be nice, if you could point me to some information about such projects, maybe even some metrics.
Any help is greatly appreciated.
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I was recently tasked with developing automated build and release pipelines for one of my company's legacy applications. After some investigation, I keep hearing from managers and other devs that certain application layers and architectures don't lend themselves to automation, particularly automated testing. Therefore, it's often suggested I shouldn't bother trying to apply DevOps principles and AT unless I want to re-architect the whole app.
The common cited example would be PL/SQL backends or monolithic architectures. I asked why these were not suitable, but never got a really clear answer. Does anyone have any insight on when automated test should not be used in favor of dumping the old architecture and starting fresh?
Short answer - ones that suffer from testability issues.
For a more in depth one, let's first admit that many software systems are untestable, or not immediately testable. So that, the effort of
trying to apply DevOps principles and AT
is far greater than the ROI. Such notorious example is Google's ReCAPTCHA, which causes some pain for the automation testing folks (like me). The devs are actually right to say that it will take be a
re-architect the whole app
journey, as testabilty is highly related to other key software qualities such as encapsulation, coupling, cohesion, and redundancy.
common cited example would be PL/SQL backends or monolithic architectures
Now, that is totally not the case. The firt one is more data-centric and requires a deeper understanding, but there are solutions to that as well. As to, single-tiered software applications - one can argue that in contrast to the mSOA, monolithic applications are much easier to debug and test. Since a monolithic app is a single indivisible unit, you can run end-to-end testing much faster/easier.
Put simply - if your app is highly testable, is highly usable. In case, the architecture and design were aligned to a very, very specific company needs - no wonder, is usable only up to a point.
I'm not necessarily looking for an example of code written on an AOP language, but some code that thoroughly and effectively divides into aspects, rather than components, so I could read it and see how to do it well.
Most of the examples of aspects I've seen are only a small part of the program (locking, logging); I don't think I've ever seen a complete semi-non-trivial program that was primarily divided along aspects.
Anyone know some good ones?
Spring Roo uses aspects quite a bit. IMO finding open-source AOP code is relatively uncommon, though; most of it I've seen IRL is embedded into closed-source, internal code.
There are a few books that discuss AOP application/architecture design which I found pretty interesting, and there are a fair number of papers that discuss non-canonical uses.
I am interested in proving that some robot controller does not reach any faulty state, which I would define by a set of predicates. I know that there are open-source software tools to achieve that. For instance, I heard of BLAST (Berkeley Lazy Abstraction Software Verification Tool), but are you aware of any other that may be simpler to use and/or more targeted to my particular application?
Have you ever used BLAST or another such tool in one of your project, and do you think that the benefits outweigh the effort needed to deploy such tools?
You might find Frama-C useful.
For evaluations by people who are not Frama-C developers, see these two articles. Some engineers developing safety-critical code (e.g. DO-178B level A) have found formal annotations and analysis based on weakest precondition techniques worth the investment, but traditional tests are very expensive for them. This last link is about Caveat, a closed-source analyzer that Frama-C intends to replace in due time.
Your question makes it sound as if you might perhaps appreciate Frama-C's Aoraï plug-in.
Whether this is all time well spent in your case is probably more a matter of whether you consider learning about these techniques a joy or a chore.
I want to know in which applications/programming domain are most suitable for Smalltalk. Could anyone please provide me some useful links that could answer my query?
Through googling I learned that some companies use it for:
logistics and foreign trade application
desktop, server and script development
data processing and logistics, scripts and presentations
but I cant find documents/research papers that can tell me which programming domain Smalltalk-80 (or Smalltalk) is best suited.
Some of the programming domains are:
- Artificial intelligence reasoning
- General purpose applications
- Financial time series analysis
- Natural language processing
- Relational database querying
- Application scripting
- Internet
- Symbolic mathematics
- Numerical mathematics
- Statistical applications
- Text processing
- Matrix algorithms
I hope you guys can help me. I am doing this for my case study. Thanks in advance.
It's a general purpose programming language. To paraphrase Kent Pitman on the question of what Common Lisp is useful for:
...Please don't assume [Smalltalk] is only
useful for Animation and Graphics, AI,
Bioinformatics, B2B and E-Commerce,
Data Mining, EDA/Semiconductor
applications, Expert Systems, Finance,
Intelligent Agents, Knowledge
Management, Mechanical CAD, Modeling
and Simulation, Natural Language,
Optimization, Research, Risk Analysis,
Scheduling, Telecom, and Web Authoring
just because these are the only things
they happened to list.
It's particularly suited for applications that cannot have downtime - it's quite normal to patch a running server in deep ways (say, by changing the shape of your class) without taking the server down - or systems that are very complex or have rapidly changing requirements.
Smalltalk has quite substantial growth recently in web based applications, thanks to innovations and fresh approaches in Aida/Web, Iliad and Seaside Smalltalk web frameworks.
In general Smalltalk is used for most complex information systems, let me mention just two:
Finance: Kapital, a risk management in JP Morgan
Manufacturing: ControlWorks, for chip manufacturing in AMD
My goal has been to do a brain dump into software. And I have found Smalltalk to be very well suited for that. Smalltalk makes it easy to put my ideas down in code. And it provides feedback to my thinking. The ability to debug infinitely deep at any point in the execution just enhances my understand of the problem to be solved. Then it allows me to carry out my solution most naturally.
Aik-Siong Koh
I'm afraid you will get as many answers as users of Smalltalk. For some it's a "way of life" for others it's a learning process and in the end they "strand" at granddaddy of the OO languages. Some are using their smalltalk as a kind of shell to "IT-problems".
For me the answer is for application development. Now this is definitive a wide field. As you figured out it is used quite "much" in the software for economic stuff. And that is where I'm using it. I've decided to use it for my Web-Development projects which are related to "business".
The domains you named are all suitable for Smalltalk. Smalltalk shows its strengths in development for systems that are engineering-time limited, instead of hardware-limited.
The Seaside web framework allows us to create complex web applications in a fraction of the time needed in other technologies. The Gemstone object-oriented database allows us to nearly ignore persistence issues.
Smalltalk is generally a very expressive, readable, and understandable language. Whenever a large codebase is to be maintained or code needs to be understandable to non-professionals, Smalltalk shines.
»Smalltalk is a vision of the computer as a medium of self expression. … A humanistic vision of the computer as something everyone could use and benefit from. If you are going to have a medium for self expression, programability is key because unless you can actually make the system behave as you want you are a slave to what’s on the machine. So it’s really vital, and so language comes to the for because it’s through language that you express yourself to the machine.« – Elliot Miranda
You can check this link: http://www.clubsmalltalk.org/web/index.php?option=com_content&view=article&id=183&Itemid=117 this is a compilation of uses of smalltalk in latam.
perhaps another way of answering the question would be by stating what it might not be suitable for. One domain would be where you have "real" real time constraints i.e. you would need to control the garbage collector from kicking off. If I recall IBM's (OTI) Smalltalk embedded had a mechanism for turning off the gc, but IBM dropped that a while ago. The other domain I have not seen much of is cell phone apps. As far as I know none of the viable Smalltalk's can run on Android but that may change. One hears of folks in Squeak/Pharo working on that. I would love to see ST running well on Android. I think that the Android tablet market will be a hot one.
I should conclude by saying that in all the years I have been coding in ST i.e. since 94, I have seen Smalltalk in just about everything else.
I cant find documents/research papers that can tell me which programming domain Smalltalk-80 (or Smalltalk) is best suited.
This is because Smalltalk is not a domain-specific language, but a general purpose language.
Things it has been used for in the past:
- as the operating system system language for personal computers
- writing rich multimedia and near real-time applications, such as sound synthesisers
- very large corporate and government data processing systems, such as the UK's Home Office Large Matter Enquiry System, or many of JPMorgan Chase's financial trading systems
- web applications, such as DabbleDB
- creating complicated development tools, such as IBM's VisualAge IDE
- experimenting and prototyping applications in early-stage development
Generally speaking Smalltalk shines where the systems are complex, development speed is a key factor, and maintainability is going to be a key factor.
I use Smalltalk to create applications to control, manage and distribute multi-platform JavaScript webapps.
I want to develope a big project, but I really don't know what is the best way to model my project. Do I even need to model my project?
What are the most practical OOP software modeling methods in real world projects? What are the best and most useful ones?
Many times its needed to capture the complex structure of classes you have in you OO system, so class diagrams from UML are used for modeling. You can also want to describe interactions of classes, for that sequence diagrams are useful. There are also other UML diagrams and each has its purpose.
If you are looking for an approach to modeling, try looking at Unified Process, which is adevelopment method, which is created by authors of UML and uses UML quite heavily and also describes how UML can be used.
Agile methodology is currently what is recommended. If you add a slice of UML then it would be better :-)
Modeling (design) is the most important part of every project.
In fact as times goes by, we sacrifice performance to gain higher level of design.
Why .NET framework is popular (compare to old tools) ? In most cases its libraries are wrappers over traditional win32 APIs, a waste of performance, instead it provides better design, which makes it easy to learn and use.
So if your project have a good design it would be easy to understand, develop, debug, maintain and extend.
Another example is OOP itself which has classes, interfaces... and bunch of constructor/destructor calls. OOP concepts are borrowed from psychiatry and the way human being see the world.
Here are two different concepts:
1) Design methodology
2) Project management methodology
There are many and I don't name good or bad. Each of them fits a scenario.
About design methodology I prefer DDD (Domain Driven Design) as it maps the industry domain terminology and concepts. So if you have a decision problem about what to do if A->B->C happened, simply you can ask a domain professional and he will say what they do in real world. DDD is good for old enough industries that have cumulative wisdom. I'm not gonna write more about design since we don't know about the project.
Project management methodologies (like agile) are the way you build the building from the map (design). The goal of project management is to use resources optimal (time, money, human resources...). This is done through work breakdown structure and make work as parallel as possible. The most known project management methodology is the traditional one in which we do everything in sequence, as civil engineers do (foundation, structure, walls...). This was good for many centuries until last decades (software industry), since in traditional project management you know where you are, where you want to go, and how to reach there. This way you can buy your furniture for a home that's a land yet !
Software industry has very rapid changes in tools and methods because is was new and no best practices were founded on thousands of failed projects. Many times when a project started it has changes because of changes in developing tools and frameworks. Other source of change is the scope of the project (where to go). Software is an intangible product so you fall in the trap of time estimations easily. For software development best practice are iterative methodologies.
Iterative methodologies suggest, a working incomplete solution which you make more complete in next iterate, rather than a non working partially complete one. This has a time overhead, instead, you sure the solution works and if any problem, you find in early stages. That's why we have nightly builds !
The best is Visual Studio 2010 Ultimate others are too cumbersome. Otherwise use light tools like yuml see http://askuml.com for samples.