57 lines
1.7 KiB
HTML
57 lines
1.7 KiB
HTML
|
<!DOCTYPE HTML PUBLIC "-//W3O//DTD W3 HTML 2.0//EN">
|
||
|
|
<!Originally converted to HTML using LaTeX2HTML 95 (Thu Jan 19 1995) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds >
|
||
|
|
<HEAD>
|
||
|
|
<TITLE> Mapcar</TITLE>
|
||
|
|
</HEAD>
|
||
|
|
<BODY>
|
||
|
|
<meta name="description" value=" Mapcar">
|
||
|
|
<meta name="keywords" value="lp">
|
||
|
|
<meta name="resource-type" value="document">
|
||
|
|
<meta name="distribution" value="global">
|
||
|
|
<P>
|
||
|
|
<BR> <HR>
|
||
|
|
<A HREF="node70.html"><IMG ALIGN=BOTTOM ALT="next" SRC="next_motif.gif"></A>
|
||
|
|
<A HREF="node64.html"><IMG ALIGN=BOTTOM ALT="up" SRC="up_motif.gif"></A>
|
||
|
|
<A HREF="node68.html"><IMG ALIGN=BOTTOM ALT="previous" SRC="previous_motif.gif"></A> <BR>
|
||
|
|
<A HREF="lp.html"><B>Contents</B></A>
|
||
|
|
<B> Next:</B>
|
||
|
|
<A HREF="node70.html"> Backquote and Commas</A>
|
||
|
|
<B>Up:</B>
|
||
|
|
<A HREF="node64.html"> FunctionsLambda Expressions, </A>
|
||
|
|
<B> Previous:</B>
|
||
|
|
<A HREF="node68.html"> Apply</A>
|
||
|
|
<BR> <HR> <P>
|
||
|
|
<H1>Mapcar</H1>
|
||
|
|
<P>
|
||
|
|
<font size=-1><em>[We are grateful to <a
|
||
|
|
href="mailto:remmers@jremmers.org">John H. Remmers</a> for allowing
|
||
|
|
material from his <a
|
||
|
|
href="http://www.emunix.emich.edu/~remmers/337/lisp-functional-features.html">programming
|
||
|
|
languages course</a> to be incorporated into this
|
||
|
|
section.]</em></font>
|
||
|
|
|
||
|
|
|
||
|
|
<P>The <TT>MAPCAR</TT> form is an "iterator" that applies a
|
||
|
|
function repeatedly, to each element of a list and returns a list of the results. For example:
|
||
|
|
|
||
|
|
|
||
|
|
<BLOCKQUOTE>
|
||
|
|
<TT>> (mapcar 'atom '(dog (cat horse) fish))<br>
|
||
|
|
(t nil t)
|
||
|
|
</TT></BLOCKQUOTE>
|
||
|
|
|
||
|
|
<BLOCKQUOTE><TT>
|
||
|
|
<TT>> (mapcar (lambda (x) (* x x)) '(4 7 2 9))<br>
|
||
|
|
(16 49 4 81)
|
||
|
|
</TT></BLOCKQUOTE>
|
||
|
|
|
||
|
|
|
||
|
|
<BR> <HR>
|
||
|
|
<P>
|
||
|
|
<ADDRESS>
|
||
|
|
<I>© Colin Allen, John H. Remmers, & Maneesh Dhagat <BR>
|
||
|
|
March 2007 </I>
|
||
|
|
</ADDRESS>
|
||
|
|
</BODY>
|
||
|
|
|