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| {{merge from|Procedural parameter|date=May 2012}}
| | If you have the desire to process settings instantaneously, loading files instantly, nevertheless your body is logy plus torpid, what would you do? If you are a giant "switchboard" that is deficiency of efficient administration program plus efficient housekeeper, what would we do? If you have send a exact commands to a mind, nevertheless the body will not do properly, what would we do? Yes! You require a full-featured repair registry!<br><br>Install an anti-virus software. If you absolutely have which on we computer then carry out a full system scan. If it finds any viruses found on the computer, delete those. Viruses invade the computer plus make it slower. To protect the computer from many viruses, it's better to keep the anti-virus software running whenever we employ the web. We might also fix the protection settings of your internet browser. It will block unknown plus risky sites and also block off any spyware or malware trying to receive into a computer.<br><br>With RegCure you are able to easily better the begin up and shut down of your computer. The program shows the scan progress and you shouldn't worry where it is actually working at that time. It shows you what happens. Dynamic link library section of the registry will result serious application failures. RegCure restores plus repairs the registry and keeps we out of DLL. RegCure can make individual corrections, so it could functions for your requires.<br><br>The 1328 error is a popular problem caused by a program being unable to correctly procedure numerous changes for the program or Microsoft Office. If you have this error, it commonly means which the computer is either unable to read the actual update file or your computer has problems with all the settings it's using to run. To fix this issue, we initially have to change / fix any problems which the computer has with its update files, and then repair some of the issues that the program can have.<br><br>Many [http://bestregistrycleanerfix.com registry cleaner] s enable you to download their product for free, to scan the computer oneself. That way we can see how various errors it finds, where it finds them, and how it will fix them. A amazing registry cleaner may remove your registry issues, plus optimize and speed up the PC, with small effort on a part.<br><br>Active X controls are used across the whole spectrum of computer plus web technologies. These controls are called the building blocks of the internet plus as the glue which puts it all together. It is a standard that is selected by all developers to create the internet more practical plus interactive. Without these control specifications there would basically be no public web.<br><br>The 'registry' is simply the central database which stores all your settings plus choices. It's a really important piece of the XP system, that means that Windows is consistently adding plus updating the files inside it. The difficulties occur when Windows actually corrupts & loses a few of these files. This makes the computer run slow, as it attempts hard to locate them again.<br><br>What I would recommend is to search on a own for registry products. You are able to do this with a Google look. Whenever you find products, look for reviews and testimonials regarding the product. Then you are able to see how others like the product, and how well it functions. |
| {{inline citations|date=September 2013}}
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| In [[mathematics]] and [[computer science]], a '''higher-order function''' (also '''functional form''', '''functional''' or '''functor''') is a [[function (mathematics)|function]] that does at least one of the following:
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| *takes one or more functions as an input
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| *outputs a function
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| All other functions are ''first-order functions''. In mathematics higher-order functions are also known as ''[[operator (mathematics)|operators]]'' or ''[[functional (mathematics)|functionals]]''. The [[derivative]] in [[calculus]] is a common example, since it maps a function to another function.
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| In the [[lambda calculus|untyped lambda calculus]], all functions are higher-order; in a [[typed lambda calculus]], from which most [[functional programming]] languages are derived, higher-order functions are values with types of the form <math>(\tau_1\to\tau_2)\to\tau_3</math>.
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| The <code>[[map (higher-order function)|map]]</code> function, found in many functional programming languages, is one example of a higher-order function. It takes as arguments a function ''f'' and a list of elements, and as the result, returns a new list with ''f'' applied to each element from the list. Another very common kind of higher-order function in those languages which support them are sorting functions which take a comparison function as a parameter, allowing the programmer to separate the sorting algorithm from the comparisons of the items being sorted. The [[C (programming language)|C]] standard [[function (computer science)|function]] <code>qsort</code> is an example of this.
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| Other examples of higher-order functions include [[fold (higher-order function)|fold]], [[function composition (computer science)|function composition]], [[integral|integration]], and the constant-function function λ''x''.λ''y''.''x''.
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| ==Example==
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| ''The following examples are not intended to compare and contrast programming languages, since each program performs a different task.''
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| This [[Python (programming language)|Python]] program defines the higher-order function <code>twice</code> which takes a function and an arbitrary object (here a number), and applies the function to the object twice. This example prints 13: twice(f, 7) = f(f(7)) = (7 + 3) + 3.
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| <source lang="python">
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| def f(x):
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| return x + 3
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| def twice(function, x):
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| return function(function(x))
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| print(twice(f, 7))
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| </source>
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| This [[Haskell (programming language)|Haskell]] code is the equivalent of the Python program above.
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| <source lang="haskell">
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| f = (+3)
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| twice function = function . function
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| main = print (twice f 7)
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| </source>
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| In this [[Scheme (programming language)|Scheme]] example the higher-order function <code>g()</code> takes a number and returns a function. The function <code>a()</code> takes a number and returns that number plus 7 (e.g. ''a''(3)=10).
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| <source lang="scheme">
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| (define (g x)
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| (lambda (y) (+ x y)))
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| (define a (g 7))
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| (display (a 3))
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| </source>
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| In this [[Erlang (programming language)|Erlang]] example the higher-order function <code>or_else</code>/2 takes a list of functions (<code>Fs</code>) and argument (<code>X</code>). It evaluates the function <code>F</code> with the argument <code>X</code> as argument. If the function <code>F</code> returns false then the next function in <code>Fs</code> will be evaluated. If the function <code>F</code> returns <code>{false,Y}</code> then the next function in <code>Fs</code> with argument <code>Y</code> will be evaluated. If the function <code>F</code> returns <code>R</code> the higher-order function <code>or_else</code>/2 will return <code>R</code>. Note that <code>X</code>, <code>Y</code>, and <code>R</code> can be functions. The example returns <code>false</code>.
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| <source lang="erlang">
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| or_else([], _) -> false;
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| or_else([F | Fs], X) -> or_else(Fs, X, F(X)).
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| or_else(Fs, X, false) -> or_else(Fs, X);
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| or_else(Fs, _, {false, Y}) -> or_else(Fs, Y);
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| or_else(_, _, R) -> R.
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| or_else([fun erlang:is_integer/1, fun erlang:is_atom/1, fun erlang:is_list/1],3.23).
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| </source>
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| In this [[JavaScript]] example the higher-order function <code>ArrayForEach</code> takes an array and a method in as arguments and calls the method on every element in the array. That is, it [[Map (higher-order function)|Map]]s the function over the array elements.
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| <source lang="javascript">
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| function ArrayForEach(array, func) {
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| for (var i = 0; i < array.length; i++) {
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| if (i in array) {
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| func(array[i]);
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| }
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| }
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| }
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| function log(msg) {
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| console.log(msg);
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| }
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| ArrayForEach([1,2,3,4,5], log);
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| </source>
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| This [[Ruby (programming language)|Ruby ]] code is the equivalent of the Python program above.
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| <source lang="ruby"> | |
| f1 = ->(x){ x + 3 }
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| def twice(f, x); f.call(f.call(x)) end
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| print twice(f1, 7)
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| </source> | |
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| ==Alternatives==
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| In programming languages that support [[function pointer]]s, one can emulate higher-order functions to some extent. Such languages include the [[C (programming language)|C]] and [[C++]] family. An example is the following C code which computes an approximation of the integral of an arbitrary function:
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| | |
| <source lang=c>
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| // Compute the integral of f() within the interval [a,b]
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| double integral(double (*f)(double x), double a, double b)
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| {
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| double sum, dt;
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| int i;
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| // Numerical integration: 0th order approximation
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| sum = 0.0;
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| dt = (b - a) / 100.0;
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| for (i = 0; i < 100; i++)
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| sum += (*f)(i * dt + a) * dt;
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| return sum;
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| }
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| </source> | |
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| Another example is the function [[qsort]] from C standard library.
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| In other [[imperative programming]] languages it is possible to achieve some of the same algorithmic results as are obtained through use of higher-order functions by dynamically executing code (sometimes called "Eval" or "Execute" operations) in the scope of evaluation. There can be significant drawbacks to this approach:
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| *The argument code to be executed is usually not [[type system#Static typing|statically typed]]; these languages generally rely on [[type system#Dynamic typing|dynamic typing]] to determine the well-formedness and safety of the code to be executed.
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| *The argument is usually provided as a string, the value of which may not be known until run-time. This string must either be compiled during program execution (using [[just-in-time compilation]]) or evaluated by [[interpreter (computing)|interpretation]], causing some added overhead at run-time, and usually generating less efficient code.
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| [[Macro (computer science)|macros]] can also be used to achieve some of the effects of higher order functions. However, macros cannot easily avoid the problem of variable capture; they may also result in large amounts of duplicated code, which can be more difficult for a compiler to optimize. Macros are generally not strongly typed, although they may produce strongly typed code.
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| In [[object-oriented programming]] languages that do not support higher-order functions, [[object (computer science)|objects]] can be an effective substitute. An object's [[method (computer science)|methods]] act in essence like functions, and a method may accept objects as parameters and produce objects as return values. Objects often carry added run-time overhead compared to pure functions, however, and added [[boilerplate code]] for defining and instantiating an object and its method(s). Languages that permit [[stack-based memory allocation|stack]]-based (versus [[dynamic memory allocation|heap]]-based) objects or [[structs]] can provide more flexibility with this method.
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| An example of using a simple stack based record in [[Free Pascal]] with a function that returns a function:
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| <source lang=pascal>
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| program example;
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| type
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| int = integer;
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| Txy = record x, y: int; end;
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| Tf = function (xy: Txy): int;
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|
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| function f(xy: Txy): int;
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| begin
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| Result := xy.y + xy.x;
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| end;
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| function g(func: Tf): Tf;
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| begin
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| result := func;
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| end;
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| var
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| a: Tf;
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| xy: Txy = (x: 3; y: 7);
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| begin
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| a := g(@f); // return a function to "a"
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| writeln(a(xy)); // prints 10
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| end.
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| </source>
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| The function <code>a()</code> takes a <code>Txy</code> record as input and returns the integer value of the sum of the record's <code>x</code> and <code>y</code> fields (3 + 7).
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| ==See also==
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| *[[First-class function]]
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| *[[Combinatory logic]]
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| *[[Function-level programming]]
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| *[[Functional programming]]
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| *[[Kappa calculus]] - a formalism for functions which ''excludes'' higher-order functions
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| *[[Strategy pattern]]
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| *[[Higher order message]]s
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| ==External links==
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| *[http://ergodicity.iamganesh.com/2006/08/07/higher-order-functions/ Higher-order functions and variational calculus]
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| *[http://boost.org/doc/html/lambda.html Boost Lambda Library for C++]
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| *[http://hop.perl.plover.com/book/ Higher Order Perl]
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| [[Category:Functional programming]]
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| [[Category:Lambda calculus]]
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| [[Category:Higher-order functions| ]]
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| [[Category:Subroutines]]
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| [[Category:Articles with example Python code]]
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| [[Category:Articles with example Haskell code]]
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| [[Category:Articles with example Scheme code]]
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| [[Category:Articles with example Erlang code]]
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| [[Category:Articles with example JavaScript code]]
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| [[Category:Articles with example C code]]
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| [[Category:Articles with example Pascal code]]
| |
If you have the desire to process settings instantaneously, loading files instantly, nevertheless your body is logy plus torpid, what would you do? If you are a giant "switchboard" that is deficiency of efficient administration program plus efficient housekeeper, what would we do? If you have send a exact commands to a mind, nevertheless the body will not do properly, what would we do? Yes! You require a full-featured repair registry!
Install an anti-virus software. If you absolutely have which on we computer then carry out a full system scan. If it finds any viruses found on the computer, delete those. Viruses invade the computer plus make it slower. To protect the computer from many viruses, it's better to keep the anti-virus software running whenever we employ the web. We might also fix the protection settings of your internet browser. It will block unknown plus risky sites and also block off any spyware or malware trying to receive into a computer.
With RegCure you are able to easily better the begin up and shut down of your computer. The program shows the scan progress and you shouldn't worry where it is actually working at that time. It shows you what happens. Dynamic link library section of the registry will result serious application failures. RegCure restores plus repairs the registry and keeps we out of DLL. RegCure can make individual corrections, so it could functions for your requires.
The 1328 error is a popular problem caused by a program being unable to correctly procedure numerous changes for the program or Microsoft Office. If you have this error, it commonly means which the computer is either unable to read the actual update file or your computer has problems with all the settings it's using to run. To fix this issue, we initially have to change / fix any problems which the computer has with its update files, and then repair some of the issues that the program can have.
Many registry cleaner s enable you to download their product for free, to scan the computer oneself. That way we can see how various errors it finds, where it finds them, and how it will fix them. A amazing registry cleaner may remove your registry issues, plus optimize and speed up the PC, with small effort on a part.
Active X controls are used across the whole spectrum of computer plus web technologies. These controls are called the building blocks of the internet plus as the glue which puts it all together. It is a standard that is selected by all developers to create the internet more practical plus interactive. Without these control specifications there would basically be no public web.
The 'registry' is simply the central database which stores all your settings plus choices. It's a really important piece of the XP system, that means that Windows is consistently adding plus updating the files inside it. The difficulties occur when Windows actually corrupts & loses a few of these files. This makes the computer run slow, as it attempts hard to locate them again.
What I would recommend is to search on a own for registry products. You are able to do this with a Google look. Whenever you find products, look for reviews and testimonials regarding the product. Then you are able to see how others like the product, and how well it functions.