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What is apply in Lisp?
apply returns the result of calling function . As with funcall , function must either be a Lisp function or a primitive function; special forms and macros do not make sense in apply . The result is a new function that accepts the rest of arguments and calls the original function with all the arguments combined.
What does Funcall do in Lisp?
Description: funcall applies function to args. If function is a symbol, it is coerced to a function as if by finding its functional value in the global environment.
What is the difference between function prototype call and function prototype apply?
call and apply are very similar—they invoke a function with a specified this context, and optional arguments. The only difference between call and apply is that call requires the arguments to be passed in one-by-one, and apply takes the arguments as an array.
What is lambda in Lisp?
A lambda expression is a function object written in Lisp. Here is an example: (lambda (x) “Return the hyperbolic cosine of X.” (* 0.5 (+ (exp x) (exp (- x))))) In Emacs Lisp, such a list is a valid expression which evaluates to a function object. A lambda expression, by itself, has no name; it is an anonymous function.
How do you define a list in Lisp?
The list function is rather used for creating lists in LISP. The list function can take any number of arguments and as it is a function, it evaluates its arguments. The first and rest functions give the first element and the rest part of a list.
What is the lambda special form used for?
Lambda is the name of a special form that generates procedures. It takes some information about the function you want to create as arguments and it returns the procedure. It’ll be easier to explain the details after you see an example.
How is FUNCALL similar to apply in C + +?
When using apply, you can see that the arguments are passed via a separate list object. With funcall, however, the arguments are passed directly in line. As you can see, the idea is quite similar to Lisp. Even in C++ (prior to C++17 ), it has always been possible to call functions and methods dynamically through respective pointers.
How is funcalland different from ordinary function call?
The difference between funcalland an ordinary function call is that in the former case the functionis obtained by ordinary evaluationof a form, and in the latter case it is obtained by the special interpretation of the function position that normally occurs. The following X3J13 cleanup issue, not part of the specification, applies to this section:
How are apply and FUNCALL similar in Lisp?
Lisp, for example, has apply and funcall. When using apply, you can see that the arguments are passed via a separate list object. With funcall, however, the arguments are passed directly in line. As you can see, the idea is quite similar to Lisp.
Is it possible to call a function through a pointer?
Calling a function (or function object) dynamically, through a pointer known at runtime, is a common programming scenario. Almost all languages support this use case. Lisp, for example, has apply and funcall. When using apply, you can see that the arguments are passed via a separate list object.