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Hold-And-Modify-Hold-And-Modify mode-Note, however, that Hold-and-Modify only applies to playfield pixels. 128 pixels of sprite data (in DMA mode) per scanline are still available for placement on top of the HAM playfield. | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-Original Chip Set HAM mode (HAM6) HAM6 mode, named for the 6 bits of data per pixel, was introduced with the Original Chip Set and was retained in the later Enhanced Chip Set and Advanced Graphics Architecture (AGA). HAM6 allows up to 4096 colors to be displayed simultaneously at resolut... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-HAM6 encoding uses six bits per pixel: two bits for control and four bits for data. If the two control bits are both set to zero, the four remaining bits are used to index one of the 16 preset color registers, operating in the fashion of a normal indexed bitmap. The other three possible ... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-This mode is not as flexible as HAM6 and not widely used.
On the AGA chipset, HAM5 no longer exists.
HAM4 It's also possible to use HAM mode with 4 bitplanes. Practical use is limited, but this technique was used in demos.
HAM7 It is possible to set up HAM mode with 7 bitplanes on OCS/EC... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-Sliced HAM mode (SHAM) The Original Amiga Chipset included a support chip known as the "Copper" that handles interrupts and other timing and housekeeping duties independently of the CPU and the video system. Using the Copper, it is possible to modify chipset registers or interrupt the CP... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-Using this technique, programmers developed the Sliced HAM or SHAM mode, also known as dynamic HAM. SHAM changes some or all color registers on selected scan lines to change the palette during display. This meant that every scan line can have its own set of 16 base colors. This removes s... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-This technique is not limited to HAM, and was widely used with the machine's more conventional graphics modes as well. Dynamic HiRes uses a similar palette changing technique to produce 16 colors per line in the high resolution modes, whereas HAM is limited to low resolution but allows b... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-Advanced Graphics Architecture HAM mode (HAM8) With the release of the Advanced Graphics Architecture (AGA) in 1992, the original HAM mode was renamed "HAM6", and a new "HAM8" mode was introduced (the numbered suffix represents the bitplanes used by the respective HAM mode). With AGA, in... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-HAM8 operates in the same way as HAM6, using two "control" bits per pixel, but with six bits of data per pixel instead of four. The set operation selects from a palette of 64 colors instead of 16. The modify operation modifies the six most significant bits of either the red, green or blu... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-The vertical display resolutions for HAM8 are the same as for HAM6. The horizontal resolution can be 320 (360 with overscan) as before, doubled to 640 (720 with overscan) or even quadrupled to 1280 pixels (1440 with overscan). The AGA chipset also introduced even higher resolutions for t... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-Like the original HAM mode, a HAM8 screen cannot display any arbitrary color at any arbitrary position, since every pixel relies on either a limited palette or relies on up to two color components of the previous pixel. As with the original HAM mode, designers may also choose to 'slice' ... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-HAM emulation HAM is unique to the Amiga and its distinct chipsets. To allow direct rendering of legacy images encoded in HAM format software-based HAM emulators have been developed which do not require the original display hardware. Pre-4.0 versions of AmigaOS can use HAM mode in the pr... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-However, if the goal is merely to display a SHAM image on a non-Amiga platform, the required color values may be pre-calculated based on the palette entries that are programmed via the Copperlist, regardless of whether the palette is modified in the middle of a scanline. It is always pos... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-Third-party HAM implementations A device produced by Black Belt known as HAM-E was able to produce images with HAM8 color depth at low horizontal resolution from an Amiga with an Original Chipset.The Amiga would be set up to produce high resolution images (640 pixels wide, 720 with overs... | milkshake721/2.1M-wiki-STEM |
Hold-And-Modify-Implementations-The HAM technique was also implemented on the HAM256 and HAM8x1 modes of ULAplus for the ZX Spectrum, where it provides the ability to display 256 colors on screen, by modifying a base 64 color palette. | milkshake721/2.1M-wiki-STEM |
Spotter Network-Spotter Network-The Spotter Network (SN) is a system that utilizes storm spotter and chaser reports of location and severe weather in a centralized framework for use by coordinators such as emergency managers, Skywarn and related spotter organizations, and the National Weather Service. It uses GPS to pr... | milkshake721/2.1M-wiki-STEM |
Spotter Network-Spotter Network-The original Spotter Network was developed by Tyler Allison. The current president of the organization is John Wetter. It became operational in April 2006 and quickly grew to over 100 spotters. Several National Weather Service (NWS) employees and other officials soon took an interest in ... | milkshake721/2.1M-wiki-STEM |
Spotter Network-Spotter Network-Several papers have been written on the use of the Spotter Network in meteorological research and operations such as: Emerging Technologies in the Field to Improve Information in Support of Operations and Research The Digital Revolution of Storm Spotting Modernizations of Training, Track... | milkshake721/2.1M-wiki-STEM |
Objective-C-Objective-C-Objective-C is a high-level general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language. Originally developed by Brad Cox and Tom Love in the early 1980s, it was selected by NeXT for its NeXTSTEP operating system. Due to Apple macOS’s d... | milkshake721/2.1M-wiki-STEM |
Objective-C-Objective-C-Objective-C source code 'messaging/implementation' program files usually have .m filename extensions, while Objective-C 'header/interface' files have .h extensions, the same as C header files. Objective-C++ files are denoted with a .mm file extension. | milkshake721/2.1M-wiki-STEM |
Objective-C-History-Objective-C was created primarily by Brad Cox and Tom Love in the early 1980s at their company Productivity Products International (PPI).Leading up to the creation of their company, both had been introduced to Smalltalk while at ITT Corporation's Programming Technology Center in 1981. The earliest w... | milkshake721/2.1M-wiki-STEM |
Objective-C-History-Love was hired by Schlumberger Research in 1982 and had the opportunity to acquire the first commercial copy of Smalltalk-80, which further influenced the development of their brainchild. In order to demonstrate that real progress could be made, Cox showed that making interchangeable software compon... | milkshake721/2.1M-wiki-STEM |
Objective-C-History-Love and Cox eventually formed PPI to commercialize their product, which coupled an Objective-C compiler with class libraries. In 1986, Cox published the main description of Objective-C in its original form in the book Object-Oriented Programming, An Evolutionary Approach. Although he was careful to... | milkshake721/2.1M-wiki-STEM |
Objective-C-History-Popularization through NeXT In 1988, NeXT licensed Objective-C from StepStone (the new name of PPI, the owner of the Objective-C trademark) and extended the GCC compiler to support Objective-C. NeXT developed the AppKit and Foundation Kit libraries on which the NeXTSTEP user interface and Interface ... | milkshake721/2.1M-wiki-STEM |
Objective-C-History-In order to circumvent the terms of the GPL, NeXT had originally intended to ship the Objective-C frontend separately, allowing the user to link it with GCC to produce the compiler executable. Though initially accepted by Richard M. Stallman, this plan was rejected after Stallman consulted with GNU'... | milkshake721/2.1M-wiki-STEM |
Objective-C-History-The GNU project started work on its free software implementation of Cocoa, named GNUstep, based on the OpenStep standard. Dennis Glatting wrote the first GNU Objective-C runtime in 1992. The GNU Objective-C runtime, which has been in use since 1993, is the one developed by Kresten Krab Thorup when h... | milkshake721/2.1M-wiki-STEM |
Objective-C-History-Apple development and Swift After acquiring NeXT in 1996, Apple Computer used OpenStep in its then-new operating system, Mac OS X. This included Objective-C, NeXT's Objective-C-based developer tool, Project Builder, and its interface design tool, Interface Builder. Both were later merged into one ap... | milkshake721/2.1M-wiki-STEM |
Objective-C-History-At WWDC 2014, Apple introduced a new language, Swift, which was characterized as "Objective-C without the C". | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Objective-C is a thin layer atop C and is a "strict superset" of C, meaning that it is possible to compile any C program with an Objective-C compiler and to freely include C language code within an Objective-C class.Objective-C derives its object syntax from Smalltalk. All of the syntax for non-objec... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Messages The Objective-C model of object-oriented programming is based on message passing to object instances. In Objective-C one does not call a method; one sends a message. This is unlike the Simula-style programming model used by C++. The difference between these two concepts is in how the code re... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Interface This is analogous to class declarations as used in other object-oriented languages, such as C++ or Python.
The interface of a class is usually defined in a header file. A common convention is to name the header file after the name of the class, e.g. Ball.h would contain the interface for th... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Internal representations of a method vary between different implementations of Objective-C. If myColor is of the class Color, instance method -changeColorToRed:green:blue: might be internally labeled _i_Color_changeColorToRed_green_blue. The i is to refer to an instance method, with the class and the... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-However, internal names of the function are rarely used directly. Generally, messages are converted to function calls defined in the Objective-C runtime library. It is not necessarily known at link time which method will be called because the class of the receiver (the object being sent the message) ... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Instantiation Once an Objective-C class is written, it can be instantiated. This is done by first allocating an uninitialized instance of the class (an object) and then by initializing it. An object is not fully functional until both steps have been completed. These steps should be accomplished with ... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Instantiation with the default, no-parameter initializer: Instantiation with a custom initializer: In the case where no custom initialization is being performed, the "new" method can often be used in place of the alloc-init messages: Also, some classes implement class method initializers. Like +new, ... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-The init message performs the set-up of the instance upon creation. The init method is often written as follows: In the above example, notice the id return type. This type stands for "pointer to any object" in Objective-C (See the Dynamic typing section).
The initializer pattern is used to assure tha... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Line 6 Returns the value of self to the caller.A non-valid object pointer has the value nil; conditional statements like "if" treat nil like a null pointer, so the initialization code will not be executed if [super init] returned nil. If there is an error in initialization the init method should perf... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-If a class has more than one initialization method, only one of them (the "designated initializer") needs to follow this pattern; others should call the designated initializer instead of the superclass initializer.
Protocols In other programming languages, these are called "interfaces". | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Objective-C was extended at NeXT to introduce the concept of multiple inheritance of specification, but not implementation, through the introduction of protocols. This is a pattern achievable either as an abstract multiple inherited base class in C++, or as an "interface" (as in Java and C#). Objecti... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-An informal protocol is a list of methods that a class can opt to implement. It is specified in the documentation, since it has no presence in the language. Informal protocols are implemented as a category (see below) on NSObject and often include optional methods, which, if implemented, can change t... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-A formal protocol is similar to an interface in Java, C#, and Ada 2005. It is a list of methods that any class can declare itself to implement. Versions of Objective-C before 2.0 required that a class must implement all methods in a protocol it declares itself as adopting; the compiler will emit an e... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-A class must be declared to implement that protocol to be said to conform to it. This is detectable at runtime. Formal protocols cannot provide any implementations; they simply assure callers that classes that conform to the protocol will provide implementations. In the NeXT/Apple library, protocols ... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-The syntax denotes that there is the abstract idea of locking. By stating in the class definition that the protocol is implemented, instances of NSLock claim that they will provide an implementation for the two instance methods. | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Dynamic typing Objective-C, like Smalltalk, can use dynamic typing: an object can be sent a message that is not specified in its interface. This can allow for increased flexibility, as it allows an object to "capture" a message and send the message to a different object that can respond to the messag... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Static typing information may also optionally be added to variables. This information is then checked at compile time. In the following four statements, increasingly specific type information is provided. The statements are equivalent at runtime, but the extra information allows the compiler to warn ... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-In Objective-C, all objects are represented as pointers, and static initialization is not allowed. The simplest object is the type that id (objc_obj *) points to, which only has an isa pointer describing its class. Other types from C, like values and structs, are unchanged because they are not part o... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Forwarding Objective-C permits the sending of a message to an object that may not respond. Rather than responding or simply dropping the message, an object can forward the message to an object that can respond. Forwarding can be used to simplify implementation of certain design patterns, such as the ... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-The Objective-C runtime specifies a pair of methods in Object forwarding methods: action methods:An object wishing to implement forwarding needs only to override the forwarding method with a new method to define the forwarding behavior. The action method performv:: need not be overridden, as this met... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Note: in OpenStep, Cocoa, and GNUstep, the commonly used frameworks of Objective-C, one does not use the Object class. The - (void)forwardInvocation:(NSInvocation *)anInvocation method of the NSObject class is used to do forwarding.
Example Here is an example of a program that demonstrates the basics... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Forwarder.h Forwarder.m Recipient.h Recipient.m main.m Notes When compiled using gcc, the compiler reports: The compiler is reporting the point made earlier, that Forwarder does not respond to hello messages. In this circumstance, it is safe to ignore the warning since forwarding was implemented. Run... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Methods within categories become indistinguishable from the methods in a class when the program is run. A category has full access to all of the instance variables within the class, including private variables. | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-If a category declares a method with the same method signature as an existing method in a class, the category's method is adopted. Thus categories can not only add methods to a class, but also replace existing methods. This feature can be used to fix bugs in other classes by rewriting their methods, ... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Other languages have attempted to add this feature in a variety of ways. TOM took the Objective-C system a step further and allowed for the addition of variables also. Other languages have used prototype-based solutions instead, the most notable being Self.
The C# and Visual Basic.NET languages imple... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Example use of categories This example builds up an Integer class, by defining first a basic class with only accessor methods implemented, and adding two categories, Arithmetic and Display, which extend the basic class. While categories can access the base class's private data members, it is often go... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Integer.h Integer.m Integer+Arithmetic.h Integer+Arithmetic.m Integer+Display.h Integer+Display.m main.m Notes Compilation is performed, for example, by: One can experiment by leaving out the #import "Integer+Arithmetic.h" (line 2) and [num1 add:num2] (line 21) and omitting Integer+Arithmetic.m in co... | milkshake721/2.1M-wiki-STEM |
Objective-C-Syntax-Posing Objective-C permits a class to wholly replace another class within a program. The replacing class is said to "pose as" the target class.
Class posing was declared deprecated with Mac OS X v10.5, and is unavailable in the 64-bit runtime. Similar functionality can be achieved by using method swi... | milkshake721/2.1M-wiki-STEM |
Objective-C-Other features-Objective-C's features often allow for flexible, and often easy, solutions to programming issues.
Delegating methods to other objects and remote invocation can be easily implemented using categories and message forwarding. | milkshake721/2.1M-wiki-STEM |
Objective-C-Other features-Swizzling of the isa pointer allows for classes to change at runtime. Typically used for debugging where freed objects are swizzled into zombie objects whose only purpose is to report an error when someone calls them. Swizzling was also used in Enterprise Objects Framework to create database ... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Objective-C++ Objective-C++ is a language variant accepted by the front-end to the GNU Compiler Collection and Clang, which can compile source files that use a combination of C++ and Objective-C syntax. Objective-C++ adds to C++ the extensions that Objective-C adds to C. As nothing is done... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-C++ namespaces cannot be declared inside an Objective-C declaration.
Objective-C declarations may appear only in global scope, not inside a C++ namespace Objective-C classes cannot have instance variables of C++ classes that lack a default constructor or that have one or more virtual metho... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Objective-C 2.0 At the 2006 Worldwide Developers Conference, Apple announced the release of "Objective-C 2.0," a revision of the Objective-C language to include "modern garbage collection, syntax enhancements, runtime performance improvements, and 64-bit support". Mac OS X v10.5, released ... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Garbage collection Objective-C 2.0 provided an optional conservative, generational garbage collector. When run in backwards-compatible mode, the runtime turned reference counting operations such as "retain" and "release" into no-ops. All objects were subject to garbage collection when garb... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Properties Objective-C 2.0 introduces a new syntax to declare instance variables as properties, with optional attributes to configure the generation of accessor methods. Properties are, in a sense, public instance variables; that is, declaring an instance variable as a property provides ex... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Properties are implemented by way of the @synthesize keyword, which generates getter (and setter, if not read-only) methods according to the property declaration. Alternatively, the getter and setter methods must be implemented explicitly, or the @dynamic keyword can be used to indicate th... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Properties can be accessed using the traditional message passing syntax, dot notation, or, in Key-Value Coding, by name via the "valueForKey:"/"setValue:forKey:" methods.
In order to use dot notation to invoke property accessors within an instance method, the "self" keyword should be used:... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Non-fragile instance variables Objective-C 2.0 provides non-fragile instance variables where supported by the runtime (i.e. when building code for 64-bit macOS, and all iOS). Under the modern runtime, an extra layer of indirection is added to instance variable access, allowing the dynamic ... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-It allows instance variables that provide the backing for properties to be synthesized at runtime without them being declared in the class's interface.
Fast enumeration Instead of using an NSEnumerator object or indices to iterate through a collection, Objective-C 2.0 offers the fast enume... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Class extensions A class extension has the same syntax as a category declaration with no category name, and the methods and properties declared in it are added directly to the main class. It is mostly used as an alternative to a category to add methods to a class without advertising them i... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Implications for Cocoa development All Objective-C applications developed for macOS that make use of the above improvements for Objective-C 2.0 are incompatible with all operating systems prior to 10.5 (Leopard). Since fast enumeration does not generate exactly the same binaries as standar... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Automatic Reference Counting Automatic Reference Counting (ARC) is a compile-time feature that eliminates the need for programmers to manually manage retain counts using retain and release. Unlike garbage collection, which occurs at run time, ARC eliminates the overhead of a separate proce... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-ARC was introduced in LLVM 3.0. This translates to Xcode 4.2 (2011), or Apple LLVM compiler 3.0.
Literals NeXT and Apple Obj-C runtimes have long included a short-form way to create new strings, using the literal syntax @"a new string", or drop to CoreFoundation constants kCFBooleanTrue an... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-When using Apple LLVM compiler 4.0 (Xcode 4.4) or later, arrays, dictionaries, and numbers (NSArray, NSDictionary, NSNumber classes) can also be created using literal syntax instead of methods. (Apple LLVM compiler 4.0 translates to open source LLVM and Clang 3.1.)Example without literals:... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Subscripting When using Apple LLVM compiler 4.0 or later, arrays and dictionaries (NSArray and NSDictionary classes) can be manipulated using subscripting. Subscripting can be used to retrieve values from indexes (array) or keys (dictionary), and with mutable objects, can also be used to s... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-mulle-objc The mulle-objc project is another re-implementation of Objective-C. It supports GCC or Clang/LLVM compilers as backends. It diverges from other runtimes in terms of syntax, semantics and ABI compatibility. It supports Linux, FreeBSD, and Windows. | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Portable Object Compiler Besides the GCC/NeXT/Apple implementation, which added several extensions to the original Stepstone implementation, another free, open-source Objective-C implementation called the Portable Object Compiler also exists. The set of extensions implemented by the Portab... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-It also includes a runtime library called ObjectPak, which is based on Cox's original ICPak101 library (which in turn derives from the Smalltalk-80 class library), and is quite radically different from the OpenStep FoundationKit.
GEOS Objective-C The PC GEOS system used a programming langu... | milkshake721/2.1M-wiki-STEM |
Objective-C-Language variants-Apple's versioning scheme for its clang-based "LLVM compiler" differs from the LLVM's open-source versioning. See Xcode § Toolchain versions for a translation GNU, GNUstep, and WinObjC The GNU project has, for a long time, been interested in a platform to port NeXT and Obj-C programs to. T... | milkshake721/2.1M-wiki-STEM |
Objective-C-Library use-Objective-C today is often used in tandem with a fixed library of standard objects (often known as a "kit" or "framework"), such as Cocoa, GNUstep or ObjFW. These libraries often come with the operating system: the GNUstep libraries often come with Linux-based distributions and Cocoa comes with ... | milkshake721/2.1M-wiki-STEM |
Objective-C-Library use-Not only did the renaming serve to differentiate the new default behavior of classes within the OpenStep API, but it allowed code that used Object—the original base class used on NeXTSTEP (and, more or less, other Objective-C class libraries)—to co-exist in the same runtime with code that used N... | milkshake721/2.1M-wiki-STEM |
Objective-C-Library use-More recently, package managers have started appearing, such as CocoaPods, which aims to be both a package manager and a repository of packages. A lot of open-source Objective-C code that was written in the last few years can now be installed using CocoaPods. | milkshake721/2.1M-wiki-STEM |
Objective-C-Analysis of the language-Objective-C implementations use a thin runtime system written in C, which adds little to the size of the application. In contrast, most object-oriented systems at the time that it was created used large virtual machine runtimes. Programs written in Objective-C tend to be not much la... | milkshake721/2.1M-wiki-STEM |
Objective-C-Analysis of the language-Likewise, the language can be implemented atop extant C compilers (in GCC, first as a preprocessor, then as a module) rather than as a new compiler. This allows Objective-C to leverage the huge existing collection of C code, libraries, tools, etc. Existing C libraries can be wrapped... | milkshake721/2.1M-wiki-STEM |
Objective-C-Analysis of the language-All of these practical changes lowered the barrier to entry, likely the biggest problem for the widespread acceptance of Smalltalk in the 1980s. | milkshake721/2.1M-wiki-STEM |
Objective-C-Analysis of the language-A common criticism is that Objective-C does not have language support for namespaces. Instead, programmers are forced to add prefixes to their class names, which are traditionally shorter than namespace names and thus more prone to collisions. As of 2007, all macOS classes and funct... | milkshake721/2.1M-wiki-STEM |
Objective-C-Analysis of the language-Since Objective-C is a strict superset of C, it does not treat C primitive types as first-class objects.
Unlike C++, Objective-C does not support operator overloading. Also unlike C++, Objective-C allows an object to directly inherit only from one class (forbidding multiple inherita... | milkshake721/2.1M-wiki-STEM |
Objective-C-Analysis of the language-Because Objective-C uses dynamic runtime typing and because all method calls are function calls (or, in some cases, syscalls), many common performance optimizations cannot be applied to Objective-C methods (for example: inlining, constant propagation, interprocedural optimizations, ... | milkshake721/2.1M-wiki-STEM |
Objective-C-Analysis of the language-Memory management The first versions of Objective-C did not support garbage collection. At the time this decision was a matter of some debate, and many people considered long "dead times" (when Smalltalk performed collection) to render the entire system unusable. Some 3rd party impl... | milkshake721/2.1M-wiki-STEM |
Objective-C-Analysis of the language-With ARC, the compiler inserts retain and release calls automatically into Objective-C code based on static code analysis. The automation relieves the programmer of having to write in memory management code. ARC also adds weak references to the Objective-C language.
Philosophical di... | milkshake721/2.1M-wiki-STEM |
Objective-C-Analysis of the language-In addition to C's style of procedural programming, C++ directly supports certain forms of object-oriented programming, generic programming, and metaprogramming. C++ also comes with a large standard library that includes several container classes. Similarly, Objective-C adds object-... | milkshake721/2.1M-wiki-STEM |
Objective-C-Analysis of the language-One notable difference is that Objective-C provides runtime support for reflective features, whereas C++ adds only a small amount of runtime support to C. In Objective-C, an object can be queried about its own properties, e.g., whether it will respond to a certain message. In C++, t... | milkshake721/2.1M-wiki-STEM |
Objective-C-Analysis of the language-The use of reflection is part of the wider distinction between dynamic (run-time) features and static (compile-time) features of a language. Although Objective-C and C++ each employ a mix of both features, Objective-C is decidedly geared toward run-time decisions while C++ is geared... | milkshake721/2.1M-wiki-STEM |
Objective-C-Analysis of the language-Generic programming and metaprogramming can be implemented in both languages using runtime polymorphism. In C++ this takes the form of virtual functions and runtime type identification, while Objective-C offers dynamic typing and reflection. Both Objective-C and C++ support compile-... | milkshake721/2.1M-wiki-STEM |
Mapping Asia-Mapping Asia-Mapping Asia was an art exhibition presented in the Asia Art Archive library in Hong Kong from May 12 to August 29, 2014. A physical unfolding of the Mapping Asia book, the exhibition manifested itself in space through artworks, objects, documentation, and videos and material from AAA's collec... | milkshake721/2.1M-wiki-STEM |
Mapping Asia-List of artists exhibited-Artists in the exhibition included Wong Hoy Cheong, MAP Office, Kwan Sheung-chi, Harry Harrison, Teboho Edkins, Zhou Tiehai, Erbossyn Meldibekov, Maria Thereza Alves, Naeem Mohaiemen, Ho Tzu Nyen, Sumangala Damodaran, Zarina Hashmi, Francisco Camacho, Karta Singh Healy, CAMP, Agha... | milkshake721/2.1M-wiki-STEM |
Mapping Asia-List of artists exhibited-An exhibition catalogue was published in conjunction with the exhibition. | milkshake721/2.1M-wiki-STEM |
Mapping Asia-Mapping Asia project-The Mapping Asia project took form in an expanded publication Mapping Asia, an exhibition, and a series of programmes between April and September 2014. Traversing land and sea, connecting Guangzhou to Peru, Lesotho and Elba with a field note-like approach that includes artwork, essays,... | milkshake721/2.1M-wiki-STEM |
Mapping Asia-Mapping Asia project-Public programs included Singing Resistance with Sumangala Damodaran, a concert featuring songs from India's anti-colonial and immediate post-colonial resistance movement, presented in collaboration with Spring Workshop. | milkshake721/2.1M-wiki-STEM |
TLN2-TLN2-Talin 2 is a protein in humans that is encoded by the TLN2 gene. It belongs to the talin protein family. This gene encodes a protein related to talin 1, a cytoskeletal protein that plays a significant role in the assembly of actin filaments. Talin-2 is expressed at high levels in cardiac muscle and functions... | milkshake721/2.1M-wiki-STEM |
TLN2-Structure-Human talin-2 is 271.4 kDa and 2542 amino acids in length. The size of talin-2 protein is similar to talin-1, and is relatively similar (74% identity, 86% similarity); the size of the talin-2 gene (200 kb) is however much larger than that of talin-1 (30 kb), due to differences in intron sizes. Talin-2 mR... | milkshake721/2.1M-wiki-STEM |
TLN2-Function-The expression of talin-2 in striated muscle is developmentally regulated. Undifferentiated myoblasts primarily express talin-1, and both mRNA and protein expression of talin-2 is upregulated during differentiation; ectopic expression of talin-2 in undifferentiated myoblasts dysregulates the actin cytoske... | milkshake721/2.1M-wiki-STEM |
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