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{{User:Mgar059:LispScreencasts}}<br />
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<!-- NOTES<br />
COMMON LISP<br />
Expression-orientated.<br />
<br />
Lisp functions are written at lists, and can be processed like data, allowing for meta programming. (prefix or polish notation)<br />
<br />
Lisp is made up of S-expressions.<br />
These are made up of lists and atoms. Lists are represented by () and can contain lists. The bits inside lists are atoms.<br />
<br />
a basic list looks like (1 2 3)<br />
<br />
<br />
<br />
''Covered in this screencast''<br />
<br />
[http://# Slides Used]<br />
<br />
==Common Lisp Semantics==<br />
<br />
===What is lisp===<br />
<br />
Lisp stands for "List Processing" language. Lisp code is represented as a giant list which allows 'macros' to preprocess the code before it is compiled. Examples of lisp lists include:<br />
<br />
(list 1 2 '3 "Four")<br />
<br />
(+ 3 4)<br />
<br />
(list 4 . 5)<br />
<br />
()<br />
<br />
(setf greeting-list '(hello . world))<br />
<br />
A list an ordered sequence of elements, where each element is either a list or an ''atom''.<br />
<br />
===Constructor Cells===<br />
<br />
Lisp code is represented as a singly linked list, with a series of "cons" or construct cells. <br/><br />
In lisp you would create one using <code>cons<code> eg:<br />
(cons 1 2) <br />
<br />
Each cons cell holds two values. Each cell usually has a pointer to a piece of information associated with it, and a pointer to the next cell which makes up a list. The first pointer can be accessed by taking the <code>(car (list 1 2 3 4))</code> or the contents of the address register.<br />
<br />
(car (list 1 2 3 4)) <br />
=> 1<br />
<br />
The cdr of a cell will give you the remaining list i.e.<br />
<br />
(cdr (list 1 2 3 4)) <br />
=> (2 3 4)<br />
<br />
There are a few shortcuts for traversing the list such as cadr caddr etc.<br />
<br />
*dotted notation.<br />
<br />
===Expressions===<br />
List uses prefix/polish notation. The first element of a list is a ''form'' and the rest of the elements are arguments.<br />
<br />
--><br />
<br />
==Further reading / Bibliography==<br />
<br />
* http://gigamonkeys.com/book/syntax-and-semantics.html<br />
* http://en.wikipedia.org/wiki/Lisp_programming_language <br />
* http://www.mactech.com/articles/mactech/Vol.01/01.06/ListProgramming/index.html<br />
* http://gigamonkeys.com/book/numbers-characters-and-strings.html<br />
* http://www.webweasel.com/lisp/doc/cl10.htm<br />
* http://www.cliki.net/Naming%20conventions<br />
* http://www.gnu.org/software/emacs/manual/html_node/cl/Numbers.html<br />
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