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67 lines
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<!-- 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: Variable *, **, ***</TITLE>
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<A NAME="ST"><A NAME="STST"><A NAME="STSTST"><I>Variable</I> <B>*, **, ***</B></A></A></A> <P>
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<P><B>Value Type:</B><P>
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<P>
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an <A REL=DEFINITION HREF="26_glo_o.htm#object"><I>object</I></A>. <P>
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<P><B>Initial Value:</B><P>
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<P>
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<A REL=DEFINITION HREF="26_glo_i.htm#implementation-dependent"><I>implementation-dependent</I></A>. <P>
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<P><B>Description:</B><P>
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<P>
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The <A REL=DEFINITION HREF="26_glo_v.htm#variable"><I>variables</I></A> <A REL=DEFINITION HREF="#ST"><B>*</B></A>, <A REL=DEFINITION HREF="#STST"><B>**</B></A>, and <A REL=DEFINITION HREF="#STSTST"><B>***</B></A> are maintained by the <A REL=DEFINITION HREF="26_glo_l.htm#lisp_read-eval-print_loop"><I>Lisp read-eval-print loop</I></A> to save the values of results that are printed each time through the loop. <P>
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The <A REL=DEFINITION HREF="26_glo_v.htm#value"><I>value</I></A> of <A REL=DEFINITION HREF="a_st.htm#ST"><B>*</B></A> is the most recent <A REL=DEFINITION HREF="26_glo_p.htm#primary_value"><I>primary value</I></A> that was printed, the <A REL=DEFINITION HREF="26_glo_v.htm#value"><I>value</I></A> of <A REL=DEFINITION HREF="#STST"><B>**</B></A> is the previous value of <A REL=DEFINITION HREF="a_st.htm#ST"><B>*</B></A>, and the <A REL=DEFINITION HREF="26_glo_v.htm#value"><I>value</I></A> of <A REL=DEFINITION HREF="#STSTST"><B>***</B></A> is the previous value of <A REL=DEFINITION HREF="#STST"><B>**</B></A>. <P>
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If several values are produced, <A REL=DEFINITION HREF="a_st.htm#ST"><B>*</B></A> contains the first value only; <A REL=DEFINITION HREF="a_st.htm#ST"><B>*</B></A> contains <A REL=DEFINITION HREF="a_nil.htm#nil"><B>nil</B></A> if zero values are produced. <P>
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The <A REL=DEFINITION HREF="26_glo_v.htm#value"><I>values</I></A> of <A REL=DEFINITION HREF="a_st.htm#ST"><B>*</B></A>, <A REL=DEFINITION HREF="#STST"><B>**</B></A>, and <A REL=DEFINITION HREF="#STSTST"><B>***</B></A> are updated immediately prior to printing the <A REL=DEFINITION HREF="26_glo_r.htm#return_value"><I>return value</I></A> of a top-level <A REL=DEFINITION HREF="26_glo_f.htm#form"><I>form</I></A> by the <A REL=DEFINITION HREF="26_glo_l.htm#lisp_read-eval-print_loop"><I>Lisp read-eval-print loop</I></A>. If the <A REL=DEFINITION HREF="26_glo_e.htm#evaluation"><I>evaluation</I></A> of such a <A REL=DEFINITION HREF="26_glo_f.htm#form"><I>form</I></A> is aborted prior to its normal return, the values of <A REL=DEFINITION HREF="a_st.htm#ST"><B>*</B></A>, <A REL=DEFINITION HREF="#STST"><B>**</B></A>, and <A REL=DEFINITION HREF="#STSTST"><B>***</B></A> are not updated. <P>
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<P><B>Examples:</B><P>
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<PRE>
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(values 'a1 'a2) => A1, A2
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'b => B
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(values 'c1 'c2 'c3) => C1, C2, C3
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(list * ** ***) => (C1 B A1)
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(defun cube-root (x) (expt x 1/3)) => CUBE-ROOT
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(compile *) => CUBE-ROOT
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(setq a (cube-root 27.0)) => 3.0
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(* * 9.0) => 27.0
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</PRE>
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</TT> <P>
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<P><B>Affected By:</B><P>
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<P>
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<A REL=DEFINITION HREF="26_glo_l.htm#lisp_read-eval-print_loop"><I>Lisp read-eval-print loop</I></A>. <P>
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<P><B>See Also:</B><P>
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<P>
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<A REL=DEFINITION HREF="f__.htm#-"><B>-</B></A> (<A REL=DEFINITION HREF="26_glo_v.htm#variable"><I>variable</I></A>), <A REL=DEFINITION HREF="f_pl.htm#PL"><B>+</B></A> (<A REL=DEFINITION HREF="26_glo_v.htm#variable"><I>variable</I></A>), <A REL=DEFINITION HREF="f_sl.htm#SL"><B>/</B></A> (<A REL=DEFINITION HREF="26_glo_v.htm#variable"><I>variable</I></A>), <A REL=CHILD HREF="25_aa.htm">Section 25.1.1 (Top level loop)</A> <P>
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<P><B>Notes:</B><P>
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<P>
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<PRE>
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* == (car /)
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** == (car //)
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*** == (car ///)
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</PRE>
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</TT> <P>
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