72 lines
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72 lines
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HTML
<!-- Common Lisp HyperSpec (TM), version 7.0 generated by Kent M. Pitman on Mon, 11-Apr-2005 2:31am EDT -->
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<TITLE>CLHS: Special Operator QUOTE</TITLE>
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<HR>
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<A NAME="quote"><I>Special Operator</I> <B>QUOTE</B></A> <P>
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<P><B>Syntax:</B><P>
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<P>
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<B>quote</B> <I>object</I> => <I>object</I><P>
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<P>
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<P><B>Arguments and Values:</B><P>
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<P>
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<I>object</I>---an <A REL=DEFINITION HREF="26_glo_o.htm#object"><I>object</I></A>; not evaluated. <P>
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<P><B>Description:</B><P>
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<P>
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The <A REL=DEFINITION HREF="#quote"><B>quote</B></A> <A REL=DEFINITION HREF="26_glo_s.htm#special_operator"><I>special operator</I></A> just returns <I>object</I>. <P>
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The consequences are undefined if <A REL=DEFINITION HREF="26_glo_l.htm#literal"><I>literal</I></A> <A REL=DEFINITION HREF="26_glo_o.htm#object"><I>objects</I></A> (including <A REL=DEFINITION HREF="26_glo_q.htm#quoted_object"><I>quoted objects</I></A>) are destructively modified. <P>
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<P><B>Examples:</B><P>
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<P>
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<PRE>
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(setq a 1) => 1
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(quote (setq a 3)) => (SETQ A 3)
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a => 1
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'a => A
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''a => (QUOTE A)
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'''a => (QUOTE (QUOTE A))
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(setq a 43) => 43
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(list a (cons a 3)) => (43 (43 . 3))
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(list (quote a) (quote (cons a 3))) => (A (CONS A 3))
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1 => 1
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'1 => 1
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"foo" => "foo"
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'"foo" => "foo"
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(car '(a b)) => A
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'(car '(a b)) => (CAR (QUOTE (A B)))
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#(car '(a b)) => #(CAR (QUOTE (A B)))
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'#(car '(a b)) => #(CAR (QUOTE (A B)))
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</PRE>
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</TT> <P>
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<P><B>Affected By:</B> None.
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<P>
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<P><B>Exceptional Situations:</B> None.
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<P>
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<P><B>See Also:</B><P>
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<P>
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<A REL=CHILD HREF="03_a.htm">Section 3.1 (Evaluation)</A>, <A REL=CHILD HREF="02_dc.htm">Section 2.4.3 (Single-Quote)</A>, <A REL=CHILD HREF="03_ba.htm">Section 3.2.1 (Compiler Terminology)</A> <P>
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<P><B>Notes:</B><P>
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<P>
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The textual notation <TT>'</TT><I>object</I><TT></TT> is equivalent to <TT>(quote </TT><I>object</I><TT>)</TT>; see <A REL=CHILD HREF="03_ba.htm">Section 3.2.1 (Compiler Terminology)</A>. <P>
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Some <A REL=DEFINITION HREF="26_glo_o.htm#object"><I>objects</I></A>, called <A REL=DEFINITION HREF="26_glo_s.htm#self-evaluating_object"><I>self-evaluating objects</I></A>, do not require quotation by <A REL=DEFINITION HREF="#quote"><B>quote</B></A>. However, <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbols</I></A> and <A REL=DEFINITION HREF="26_glo_l.htm#list"><I>lists</I></A> are used to represent parts of programs, and so would not be useable as constant data in a program without <A REL=DEFINITION HREF="#quote"><B>quote</B></A>. Since <A REL=DEFINITION HREF="#quote"><B>quote</B></A> suppresses the <A REL=DEFINITION HREF="26_glo_e.htm#evaluation"><I>evaluation</I></A> of these <A REL=DEFINITION HREF="26_glo_o.htm#object"><I>objects</I></A>, they become data rather than program. <P>
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<P><HR>The following <A REL=META HREF="../Front/X3J13Iss.htm">X3J13 cleanup issue</A>, <I>not part of the specification</I>, applies to this section:<P><UL><LI> <A REL=CHILD HREF="../Issues/iss083.htm">CONSTANT-MODIFICATION:DISALLOW</A><P></UL><HR>
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