68 lines
4.1 KiB
HTML
68 lines
4.1 KiB
HTML
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<TITLE>CLHS: Function ZEROP</TITLE>
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<A NAME="zerop"><I>Function</I> <B>ZEROP</B></A> <P>
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<P><B>Syntax:</B><P>
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<P>
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<B>zerop</B> <I>number</I> => <I>generalized-boolean</I><P>
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<P>
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<P><B>Pronunciation:</B><P>
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<P>
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['zee(,)roh(,)pee] <P>
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<P><B>Arguments and Values:</B><P>
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<P>
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<I>number</I>---a <A REL=DEFINITION HREF="26_glo_n.htm#number"><I>number</I></A>. <P>
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<I>generalized-boolean</I>---a <A REL=DEFINITION HREF="26_glo_g.htm#generalized_boolean"><I>generalized boolean</I></A>. <P>
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<P><B>Description:</B><P>
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<P>
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Returns <A REL=DEFINITION HREF="26_glo_t.htm#true"><I>true</I></A> if <I>number</I> is zero (<A REL=DEFINITION HREF="26_glo_i.htm#integer"><I>integer</I></A>, <A REL=DEFINITION HREF="26_glo_f.htm#float"><I>float</I></A>, or <A REL=DEFINITION HREF="26_glo_c.htm#complex"><I>complex</I></A>); otherwise, returns <A REL=DEFINITION HREF="26_glo_f.htm#false"><I>false</I></A>. <P>
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Regardless of whether an <A REL=DEFINITION HREF="26_glo_i.htm#implementation"><I>implementation</I></A> provides distinct representations for positive and negative floating-point zeros, <TT>(zerop -0.0)</TT> always returns <A REL=DEFINITION HREF="26_glo_t.htm#true"><I>true</I></A>. <P>
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<P><B>Examples:</B><P>
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<P>
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<PRE>
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(zerop 0) => <A REL=DEFINITION HREF="26_glo_t.htm#true">true</A>
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(zerop 1) => <A REL=DEFINITION HREF="26_glo_f.htm#false">false</A>
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(zerop -0.0) => <A REL=DEFINITION HREF="26_glo_t.htm#true">true</A>
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(zerop 0/100) => <A REL=DEFINITION HREF="26_glo_t.htm#true">true</A>
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(zerop #c(0 0.0)) => <A REL=DEFINITION HREF="26_glo_t.htm#true">true</A>
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</PRE>
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</TT> <P>
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<P><B>Side Effects:</B> None.
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<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><P>
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<P>
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Should signal an error of <A REL=DEFINITION HREF="26_glo_t.htm#type"><I>type</I></A> <A REL=DEFINITION HREF="e_tp_err.htm#type-error"><B>type-error</B></A> if <I>number</I> is not a <A REL=DEFINITION HREF="26_glo_n.htm#number"><I>number</I></A>. <P>
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<P><B>See Also:</B> None.
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<P>
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<P><B>Notes:</B><P>
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<P>
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<PRE>
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(zerop number) == (= number 0)
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</PRE>
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</TT> <P>
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