defun (short for “define function”) is a macro in the Lisp family of programming languages that defines a function in the global environment that uses the form: (defun ( ) “optional documentation” …)

What is written in Common Lisp?

Usually only a few things are written in C and most of the language including the (native) code compilers are written in Common Lisp. Usually not just the “library” is written in Lisp. But most of the core data structures, garbage collection, the compiler(s) etc. are written in Lisp.

Who invented Common Lisp?

John McCarthy
Lisp/Designed by
LISP, in full list processing, a computer programming language developed about 1960 by John McCarthy at the Massachusetts Institute of Technology (MIT). LISP was founded on the mathematical theory of recursive functions (in which a function appears in its own definition).

What is Common Lisp compare it with Lisp?

Common Lisp (CL) is a dialect of the Lisp programming language, published in ANSI standard document ANSI INCITS 226-1994 (S20018) (formerly X3. Common Lisp sought to unify, standardise, and extend the features of these MacLisp dialects. Common Lisp is not an implementation, but rather a language specification.

What is Lisp syntax?

The syntactic elements of the Lisp programming language are symbolic expressions, also known as s-expressions. Lisp atoms are the basic syntactic units of the language and include both numbers and symbols. Symbolic atoms are composed of letters, numbers, and the non-alphanumeric characters.

How do you define a function in a Common Lisp?

Use defun to define your own functions in LISP. Defun requires you to provide three things. The first is the name of the function, the second is a list of parameters for the function, and the third is the body of the function — i.e. LISP instructions that tell the interpreter what to do when the function is called.

Who uses LISP today?

Boeing 747 and 777 use Allegro NFS Server written in Common Lisp. Further on the subject of aviation: Boeing and Airbus use Piano – a software package in Common Lisp for aircraft design development and analysis. You can learn more about the low-level programming in Common Lisp from this talk.

How do you compare 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.

What is a list in Lisp?

An association list, or a-list, is a data structure used very frequently in Lisp. An a-list is a list of pairs (conses); each pair is an association. The car of a pair is called the key, and the cdr is called the datum.

What is defdefstar in Lisp?

Defstar is a collection of Common Lisp macros that can be used in place of defun, defmethod, defgeneric, defvar, defparameter, flet, labels , let* and lambda. Each macro has the same name as the form it replaces, with a star added at the end, e.g. defun*. (the exception is the let* replacement, which is called *let ).

What is Common Lisp quick reference?

Common Lisp Quick Reference is a free booklet with short descriptions of the thousand or so symbols defined in the ANSI standard. It comes with a comprehensive index.

What is type test in lambda list in Lisp?

Where the name of an argument appears in a lambda list, a clause of the form (name TYPE [TEST]) may appear instead. TYPE is any legal Common Lisp type declaration, for example integer or (real 0 100). TEST is an optional test which the supplied value of the argument must pass at runtime.

How do you use defdefun in Python?

defun can be used to define a new function, to install a corrected version of an incorrect definition, to redefine an already-defined function, or to redefine a macro as a function. defun implicitly puts a block named block-name around the body forms (but not the forms in the lambda-list) of the function defined.