What does Setf do 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.
How do you use equal in a Lisp?
To compare the characters of two strings, one should use equal, equalp, string=, or string-equal. Compatibility note: The Common Lisp function eql is similar to the Interlisp function eqp.
How do you define a list in Lisp?
It takes two arguments, an element and a list and returns a list with the element inserted at the first place. It takes any number of arguments and returns a list with the arguments as member elements of the list. It merges two or more list into one. It takes a list and returns a list containing the last element.
How do I add elements to a list in Scheme?
The append function joins two lists together to make one. The append function is built into Scheme. It concatenates two lists, that is to say, given two lists list1 and list2 it produces a new list which starts with the same elements as list1 and finishes with those of list2 .
What is an atom in LISP?
In Lisp, all of the quoted text including the punctuation mark and the blank spaces is a single atom. This kind of atom is called a string (for “string of characters”) and is the sort of thing that is used for messages that a computer can print for a human to read.
How many arguments do SETQ can have in single braces?
3. How many arguments do setf or setq can have in single braces? d) Any even number of arguments. Explanation: The setf and setq takes any number of arguments but the number must be even.
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.
What does cons mean in Lisp?
In computer programming, cons (/ˈkɒnz/ or /ˈkɒns/) is a fundamental function in most dialects of the Lisp programming language. cons constructs memory objects which hold two values or pointers to two values. These objects are referred to as (cons) cells, conses, non-atomic s-expressions (“NATSes”), or (cons) pairs.
What is member in Scheme?
member is a function that treats a list as a set. It returns true if the item is found in the list, and false otherwise.
What is the difference between a list and a sub list?
The difference between a sentence and a list is that the elements of a sentence must be words, whereas the elements of a list can be anything at all: words, #t , procedures, or other lists. (A list that’s an element of another list is called a sublist.
What are the three basic building blocks of Lisp?
Basic Building Blocks in LISP An atom is a number or string of contiguous characters. It includes numbers and special characters. A list is a sequence of atoms and/or other lists enclosed in parentheses. A string is a group of characters enclosed in double quotation marks.