Dynamic type languages versus static type languages. Well, both are very, very very very misunderstood and also two completely different things. Static types are a restriction of the grammar of the language. Statically typed langauges strictly could be said to not be context free. The simple truth is that it becomes inconvenient to express a language sanely in context free grammars that doesnt treat all its data simply as bit vectors. Static type systems are part of the grammar of the language if any, they simply restrict it more than a context free grammar could, grammatical checks thus happen in two passes over the source really. Static types correspond to the mathematical notion of type theory, type theory in mathematics simply restricts the legality of some expressions. Like, I cant say 3 4,7 in maths, this is because of the type theory of it. Software prototyping is the activity of creating prototypes of software applications, i. Static types are thus not a way to prevent errors from a theoretical perspective, they are a limitation of the grammar. Indeed, provided that, 3 and intervals have the usual set theoretical definitions, if we remove the type system 3 4,7has a pretty well defined result thats a set. Operations are still just the shifting and manipulation of bits of course. The catch to this is that a type system cant decide if such operations are going to occur or not if it would be allowed to run. As in, exactly partition the set of all possible programs in those that are going to have a type error, and those that arent. It can do only two things 1 prove that type errors are going to occur in a program. Griktait J. 2008 Business process modelling and simulation advantages and disadvantages. Global Academic Society Journal Social Science Insight, Vol. No. 3. In todays world, fabricators have a wide range of choices in deciding the best welding process and consumable to use in a particular application. Use case testing is a technique that helps us identify test cases that exercise the whole system on a transaction by transaction basis from start to finish. Issuu is a digital publishing platform that makes it simple to publish magazines, catalogs, newspapers, books, and more online. Easily share your publications and get. End of 1990s Foundation of the Open Source Initiative. In the early days of computing, programmers and developers shared software in order to learn from each other. This might seem like Im contradicting myself. But what a C or Java type checker does is it rejects a program as ungrammatical, or as it calls it type error if it cant succeed at 2. It cant prove they arent going to occur, that doesnt mean that they arent going to occur, it just means it cant prove it. It might very well be that a program which will not have a type error is rejected simply because it cant be proven by the compiler. A simple example being if1 a 3 else a string, surely since its always true, the else branch will never be executed in the program, and no type error shall occur. But it cant prove these cases in a general way, so its rejected. This is the major weakness of a lot of statically typed languages, in protecting you against yourself, youre necessarily also protected in cases you dont need it. But, contrary to popular believe, there are also statically typed languages that work by principle 1. They simply reject all programs of which they can prove its going to cause a type error, and pass all programs of which they cant. So its possible they allow programs which have type errors in them, a good example being Typed Racket, its hybrid between dynamic and static typing. And some would argue that you get the best of both worlds in this system. Another advantage of static typing is that types are known at compile time, and thus the compiler can use this. If we in Java do string string or 3 3, both tokens in text in the end represent a completely different operation and datum, the compiler knows which to choose from the types alone. Now, Im going to make a very controversial statement here but bare with me dynamic typing does not exist. Sounds very controversial, but its true, dynamically typed languages are from a theoretical perspective untyped. They are just statically typed languages with only one type. Or simply put, they are languages that are indeed grammatically generated by a context free grammar in practice. Why dont they have types Because every operation is defined and allowed on every operant, whats a runtime type error exactly Its from a theoretical example purely a side effect. If doing printstring which prints a string is an operation, then so is length3, the former has the side effect of writing string to the standard output, the latter simply error function length expects array as argument., thats it. There is from a theoretical perspective no such thing as a dynamically typed language. They are untyped. Images/CS_EMEA/Application_Stories/Automation/Images/Advantages_Disadvantages.png' alt='Advantages And Disadvantages Of Case Tools In Software Engineering' title='Advantages And Disadvantages Of Case Tools In Software Engineering' />All right, the obvious advantage of dynamically typed language is expressive power, a type system is nothing but a limitation of expressive power. And in general, languages with a type system indeed would have a defined result for all those operations that are not allowed if the type system was just ignored, the results would just not make sense to humans. Many languages lose their Turing completeness after applying a type system. Components%20of%20the%20Database%20System%20Environment.jpg' alt='Advantages And Disadvantages Of Case Tools In Software Engineering' title='Advantages And Disadvantages Of Case Tools In Software Engineering' />The obvious disadvantage is the fact that operations can occur which would produce results which are nonsensical to humans. To guard against this, dynamically typed languages typically redefine those operations, rather than producing that nonsensical result they redefine it to having the side effect of writing out an error, and possibly halting the program altogether. This is not an error at all, in fact, the language specification usually implies this, this is as much behaviour of the language as printing a string from a theoretical perspective. Type systems thus force the programmer to reason about the flow of the code to make sure that this doesnt happen. Engineering Phase In this phase software is developed, along with testing at the end of the phase. Hence in this phase the development and testing is done. USE OF SECONDARY DATAAdvantages, Disadvantages, Secondary Survey Data Research Methods Formal Sciences Statistics Business. In my experience the reluctance to discuss the disadvantages of rules based systems comes from the fact that most criticism the rules based practitioner encounters. Or indeed, reason so that it does happen can also be handy in some points for debugging, showing that its not an error at all but a well defined property of the language. In effect, the single remnant of dynamic typing that most languages have is guarding against a division by zero. This is what dynamic typing is, there are no types, there are no more types than that zero is a different type than all the other numbers. What people call a type is just another property of a datum, like the length of an array, or the first character of a string. And many dynamically typed languages also allow you to write out things like error the first character of this string should be a z. Another thing is that dynamically typed languages have the type available at runtime and usually can check it and deal with it and decide from it. Of course, in theory its no different than accessing the first char of an array and seeing what it is. In fact, you can make your own dynamic C, just use only one type like long long int and use the first 8 bits of it to store your type in and write functions accordingly that check for it and perform float or integer addition. You have a statically typed language with one type, or a dynamic language. In practise this all shows, statically typed languages are generally used in the context of writing commercial software, whereas dynamically typed languages tend to be used in the context of solving some problems and automating some tasks. Writing code in statically typed languages simply takes long and is cumbersome because you cant do things which you know are going to turn out okay but the type system still protects you against yourself for errors you dont make. Many coders dont even realize that they do this because its in their system but when you code in static languages, you often work around the fact that the type system wont let you do things that cant go wrong, because it cant prove it wont go wrong. As I noted, statically typed in general means case 2, guilty until proven innocent. But some languages, which do not derive their type system from type theory at all use rule 1 Innocent until proven guilty, which might be the ideal hybrid. So, maybe Typed Racket is for you. Also, well, for a more absurd and extreme example, Im currently implementing a language where types are truly the first character of an array, they are data, data of the type, type, which is itself a type and datum, the only datum which has itself as a type. Types are not finite or bounded statically but new types may be generated based on runtime information. Open source software Wikipedia. Open source software OSS is computer software with its source code made available with a license in which the copyright holder provides the rights to study, change, and distribute the software to anyone and for any purpose. Open source software may be developed in a collaborative public manner. According to scientists who studied it, open source software is a prominent example of open collaboration. The term is often written without a hyphen as open source software. Open source software development, or collaborative development from multiple independent sources, generates an increasingly more diverse scope of design perspective than any one company is capable of developing and sustaining long term. A 2. 00. 8 report by the Standish Group states that adoption of open source software models has resulted in savings of about 6. HistoryeditEnd of 1. Foundation of the Open Source InitiativeeditIn the early days of computing, programmers and developers shared software in order to learn from each other and evolve the field of computing. Eventually the open source notion moved to the way side of commercialization of software in the years 1. In 1. 99. 7, Eric Raymond published The Cathedral and the Bazaar, a reflective analysis of the hacker community and free software principles. The paper received significant attention in early 1. Netscape Communications Corporation to release their popular Netscape Communicator Internet suite as free software. This source code subsequently became the basis behind Sea. Monkey, Mozilla Firefox, Thunderbird and Kompo. Zer. Netscapes act prompted Raymond and others to look into how to bring the Free Software Foundations free software ideas and perceived benefits to the commercial software industry. They concluded that FSFs social activism was not appealing to companies like Netscape, and looked for a way to rebrand the free software movement to emphasize the business potential of sharing and collaborating on software source code. The new term they chose was open source, which was soon adopted by Bruce Perens, publisher Tim OReilly, Linus Torvalds, and others. The Open Source Initiative was founded in February 1. While the Open Source Initiative sought to encourage the use of the new term and evangelize the principles it adhered to, commercial software vendors found themselves increasingly threatened by the concept of freely distributed software and universal access to an applications source code. A Microsoft executive publicly stated in 2. I cant imagine something that could be worse than this for the software business and the intellectual property business. However, while FOSS has historically played a role outside of the mainstream of private software development, companies as large as Microsoft have begun to develop official open source presences on the Internet. IBM, Oracle, Google and State Farm are just a few of the companies with a serious public stake in todays competitive open source market. There has been a significant shift in the corporate philosophy concerning the development of FOSS. The free software movement was launched in 1. In 1. 99. 8, a group of individuals advocated that the term free software should be replaced by open source software OSS as an expression which is less ambiguous1. Software developers may want to publish their software with an open source license, so that anybody may also develop the same software or understand its internal functioning. With open source software, generally anyone is allowed to create modifications of it, port it to new operating systems and instruction set architectures, share it with others or, in some cases, market it. Scholars Casson and Ryan have pointed out several policy based reasons for adoption of open source in particular, the heightened value proposition from open source when compared to most proprietary formats in the following categories Security. Affordability. Transparency. Perpetuity. Interoperability. Flexibility. Localizationparticularly in the context of local governments who make software decisions. Casson and Ryan argue that governments have an inherent responsibility and fiduciary duty to taxpayers which includes the careful analysis of these factors when deciding to purchase proprietary software or implement an open source option. The Open Source Definition, notably, presents an open source philosophy, and further defines the terms of use, modification and redistribution of open source software. Software licenses grant rights to users which would otherwise be reserved by copyright law to the copyright holder. Several open source software licenses have qualified within the boundaries of the Open Source Definition. The most prominent and popular example is the GNU General Public License GPL, which allows free distribution under the condition that further developments and applications are put under the same licence, thus also free. The open source label came out of a strategy session held on April 7, 1. Palo Alto in reaction to Netscapes January 1. Navigator as Mozilla. A group of individuals at the session included Tim OReilly, Linus Torvalds, Tom Paquin, Jamie Zawinski, Larry Wall, Brian Behlendorf, Sameer Parekh, Eric Allman, Greg Olson, Paul Vixie, John Ousterhout, Guido van Rossum, Philip Zimmermann, John Gilmore and Eric S. Raymond. 1. 8 They used the opportunity before the release of Navigators source code to clarify a potential confusion caused by the ambiguity of the word free in English. Many people claimed that the birth of the Internet, since 1. The Free Software Foundation FSF, started in 1. Since a great deal of free software already was and still is free of charge, such free software became associated with zero cost, which seemed anti commercial. The Open Source Initiative OSI was formed in February 1. Eric Raymond and Bruce Perens. With at least 2. 0 years of evidence from case histories of closed software development versus open development already provided by the Internet developer community, the OSI presented the open source case to commercial businesses, like Netscape. The OSI hoped that the use of the label open source, a term suggested by Peterson of the Foresight Institute at the strategy session, would eliminate ambiguity, particularly for individuals who perceive free software as anti commercial. Download Free Movie Batman 3 Game. They sought to bring a higher profile to the practical benefits of freely available source code, and they wanted to bring major software businesses and other high tech industries into open source. Perens attempted to register open source as a service mark for the OSI, but that attempt was impractical by trademark standards. Meanwhile, due to the presentation of Raymonds paper to the upper management at NetscapeRaymond only discovered when he read the Press Release,2. Netscape CEO Jim Barksdales PA later in the dayNetscape released its Navigator source code as open source, with favorable results. DefinitionseditThe Open Source Initiatives OSI definition is recognized by governments internationally2. In addition, many of the worlds largest open source software projects and contributors, including Debian, Drupal Association, Free. BSD Foundation, Linux Foundation, Mozilla Foundation, Wikimedia Foundation, Wordpress Foundation have committed2. OSIs mission and Open Source Definition through the OSI Affiliate Agreement. OSI uses The Open Source Definition to determine whether it considers a software license open source. The definition was based on the Debian Free Software Guidelines, written and adapted primarily by Perens. Perens did not base his writing on the four freedoms from the Free Software Foundation FSF, which were only widely available later.