46 lines
1.3 KiB
HTML
46 lines
1.3 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> Backquote and Commas</TITLE>
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</HEAD>
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<BODY>
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<meta name="description" value=" Backquote and Commas">
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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="node71.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="node69.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="node71.html"> Defmacro</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="node69.html"> Mapcar</A>
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<BR> <HR> <P>
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<H1> Backquote and Commas</H1>
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<P>
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Backquoted lists allow evaluation of items that are preceded by commas.
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<p>
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For example:
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<pre>
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>`(2 ,(+ 3 4))
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(2 7)
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</pre>
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Any number of commas may appear inside a backquoted list, and at any
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depth inside that context. For example:
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<pre>
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> `(4 ,(+ 1 2) '(3 ,(+ 1 2)) 5)
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(4 3 '(3 3) 5)
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</pre>
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<BR> <HR>
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<P>
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<ADDRESS>
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<I>© Colin Allen & Maneesh Dhagat <BR>
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March 2007 </I>
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</ADDRESS>
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</BODY>
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