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