What is the difference between SETQ and Setf?
What is the difference between setf and setq? Explanation: Setq is used only for setting the values of symbols but setf can be used for anything. Explanation: Setq is used only for symbols and setf is used for any data type, so Setf can be used in place of setq but setq cannot be used in place of setf.
What does SETQ mean in Lisp?
(setq var1 form1 var2 form2 …) is the simple variable assignment statement of Lisp. First form1 is evaluated and the result is stored in the variable var1, then form2 is evaluated and the result stored in var2, and so forth. setq may be used for assignment of both lexical and dynamic variables.
What is Setf in Lisp?
setf is actually a macro that examines an access form and produces a call to the corresponding update function. Given the existence of setf in Common Lisp, it is not necessary to have setq, rplaca, and set; they are redundant. They are retained in Common Lisp because of their historical importance in Lisp.
What is Defvar Lisp?
In Emacs Lisp, a variable such as the kill-ring is created and given an initial value by using the defvar special form. The name comes from “define variable”. The defvar special form is similar to setq in that it sets the value of a variable.
What is let in Lisp?
The let expression is a special form in Lisp that you will need to use in most function definitions. let is used to attach or bind a symbol to a value in such a way that the Lisp interpreter will not confuse the variable with a variable of the same name that is not part of the function.
How do you define a function in a Lisp?
In Lisp, a symbol such as mark-whole-buffer has code attached to it that tells the computer what to do when the function is called. This code is called the function definition and is created by evaluating a Lisp expression that starts with the symbol defun (which is an abbreviation for define function).
Do times LISP?
Common LISP provides several means to do iteration, including loop, do, do*, dotimes, and dolist. The body of a dotimes statement is just like the body of a defun — it may be any arbitrarily long sequence of LISP expressions.
How do you declare variables in LISP?
Since there is no type declaration for variables in LISP, you directly specify a value for a symbol with the setq construct.
How do you increment a Lisp?
1 Answer. Use the built-in “+” or “-” functions, or their shorthand “1+” or “1-“, if you just want to use the result, without modifying the original number (the argument). If you do want to modify the original place (containing a number), then use the built-in “incf” or “decf” functions.
How are variables defined in LISP?
How do you increment a LISP?
Why do lisps happen?
Most lisps are caused by wrong tongue placements in the mouth, which in turn obstructs air flow from the inside of the mouth, causing the distortion of words and syllables. Tongue-ties are also considered a probable cause of lisping.
What’s the difference between set and SETF in Lisp?
Originally, in Lisp, there were no lexical variables — only dynamic ones. And there was no SETQ or SETF, just the SET function. Then lexical variables happened, and SETQ came to be used for assignment to them too — so it was no longer a simple wrapper around SET.
What’s the difference between setq, SETF, and setq?
So that symbol macros could work transparently, it was realized that SETQ would have to act like SETF if the “variable” being assigned to was really a symbol macro: (defvar *hidden* (cons 42 42)) (define-symbol-macro foo (car *hidden*)) foo => 42 (setq foo 13) foo => 13 *hidden* => (13 .
What’s the difference between DEFPARAMETER and SETF?
DEFPARAMETER always assigns a value. So: SETF is a macro which uses SETQ internally, but has more possibilities. In a way it’s a more general assignment operator. E.g. with SETF you can do:
What’s the difference between DEFVAR and defparameter in Lisp?
After that, we call both functions, inside closures binding a value to a variable of the same name. In the dynamic scoping case, it is the same variable. In the lexical closure case (b), they merely have the same name, but are not the same variable, since they’re defined in two different lexical closures.