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65 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: Function IMPORT</TITLE>
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<H1><A REV=MADE HREF="http://www.lispworks.com/"><IMG WIDTH=80 HEIGHT=65 ALT="[LISPWORKS]" SRC="../Graphics/LWSmall.gif" ALIGN=Bottom></A><A REL=TOP HREF="../Front/index.htm"><IMG WIDTH=237 HEIGHT=65 ALT="[Common Lisp HyperSpec (TM)]" SRC="../Graphics/CLHS_Sm.gif" ALIGN=Bottom></A> <A REL=PREV HREF="f_find_a.htm"><IMG WIDTH=40 HEIGHT=40 ALT="[Previous]" SRC="../Graphics/Prev.gif" ALIGN=Bottom></A><A REL=UP HREF="c_packag.htm"><IMG WIDTH=40 HEIGHT=40 ALT="[Up]" SRC="../Graphics/Up.gif" ALIGN=Bottom></A><A REL=NEXT HREF="f_list_a.htm"><IMG WIDTH=40 HEIGHT=40 ALT="[Next]" SRC="../Graphics/Next.gif" ALIGN=Bottom></A></H1>
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<A NAME="import"><I>Function</I> <B>IMPORT</B></A> <P>
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<P><B>Syntax:</B><P>
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<P>
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<B>import</B> <I>symbols <TT>&optional</TT> package</I> => <I><A REL=DEFINITION HREF="a_t.htm#t"><B>t</B></A></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>symbols</I>---a <A REL=DEFINITION HREF="26_glo_d.htm#designator"><I>designator</I></A> for a <A REL=DEFINITION HREF="26_glo_l.htm#list"><I>list</I></A> of <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbols</I></A>. <P>
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<I>package</I>---a <A REL=DEFINITION HREF="26_glo_p.htm#package_designator"><I>package designator</I></A>. The default is the <A REL=DEFINITION HREF="26_glo_c.htm#current_package"><I>current package</I></A>. <P>
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<P><B>Description:</B><P>
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<P>
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<A REL=DEFINITION HREF="#import"><B>import</B></A> adds <I>symbol</I> or <I>symbols</I> to the internals of <I>package</I>, checking for name conflicts with existing <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbols</I></A> either <A REL=DEFINITION HREF="26_glo_p.htm#present"><I>present</I></A> in <I>package</I> or <A REL=DEFINITION HREF="26_glo_a.htm#accessible"><I>accessible</I></A> to it. Once the <I>symbols</I> have been <I>imported</I>, they may be referenced in the <I>importing</I> <I>package</I> without the use of a <A REL=DEFINITION HREF="26_glo_p.htm#package_prefix"><I>package prefix</I></A> when using the <A REL=DEFINITION HREF="26_glo_l.htm#lisp_reader"><I>Lisp reader</I></A>. <P>
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A name conflict in <A REL=DEFINITION HREF="#import"><B>import</B></A> between the <I>symbol</I> being imported and a symbol inherited from some other <A REL=DEFINITION HREF="26_glo_p.htm#package"><I>package</I></A> can be resolved in favor of the <I>symbol</I> being <I>imported</I> by making it a shadowing symbol, or in favor of the <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A> already <A REL=DEFINITION HREF="26_glo_a.htm#accessible"><I>accessible</I></A> by not doing the <A REL=DEFINITION HREF="#import"><B>import</B></A>. A name conflict in <A REL=DEFINITION HREF="#import"><B>import</B></A> with a <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A> already <A REL=DEFINITION HREF="26_glo_p.htm#present"><I>present</I></A> in the <I>package</I> may be resolved by uninterning that <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A>, or by not doing the <A REL=DEFINITION HREF="#import"><B>import</B></A>. <P>
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The imported <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A> is not automatically exported from the <A REL=DEFINITION HREF="26_glo_c.htm#current_package"><I>current package</I></A>, but if it is already <A REL=DEFINITION HREF="26_glo_p.htm#present"><I>present</I></A> and external, then the fact that it is external is not changed. If any <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A> to be <I>imported</I> has no home package (i.e., <TT>(symbol-package </TT><I>symbol</I><TT>) => nil</TT>), <A REL=DEFINITION HREF="#import"><B>import</B></A> sets the <A REL=DEFINITION HREF="26_glo_h.htm#home_package"><I>home package</I></A> of the <I>symbol</I> to <I>package</I>. <P>
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If the <I>symbol</I> is already <A REL=DEFINITION HREF="26_glo_p.htm#present"><I>present</I></A> in the importing <I>package</I>, <A REL=DEFINITION HREF="#import"><B>import</B></A> has no effect. <P>
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<P><B>Examples:</B><P>
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<P>
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<PRE>
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(import 'common-lisp::car (make-package 'temp :use nil)) => T
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(find-symbol "CAR" 'temp) => CAR, :INTERNAL
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(find-symbol "CDR" 'temp) => NIL, NIL
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</PRE>
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</TT> <P>
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The form <TT>(import 'editor:buffer)</TT> takes the external symbol named <TT>buffer</TT> in the <TT>EDITOR</TT> package (this symbol was located when the form was read by the <A REL=DEFINITION HREF="26_glo_l.htm#lisp_reader"><I>Lisp reader</I></A>) and adds it to the <A REL=DEFINITION HREF="26_glo_c.htm#current_package"><I>current package</I></A> as an <A REL=DEFINITION HREF="26_glo_i.htm#internal_symbol"><I>internal symbol</I></A>. The symbol <TT>buffer</TT> is then <A REL=DEFINITION HREF="26_glo_p.htm#present"><I>present</I></A> in the <A REL=DEFINITION HREF="26_glo_c.htm#current_package"><I>current package</I></A>. <P>
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<P><B>Side Effects:</B><P>
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<P>
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The package system is modified. <P>
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<P><B>Affected By:</B><P>
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<P>
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Current state of the package system. <P>
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<P><B>Exceptional Situations:</B><P>
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<P>
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<A REL=DEFINITION HREF="#import"><B>import</B></A> signals a <A REL=DEFINITION HREF="26_glo_c.htm#correctable"><I>correctable</I></A> error of <A REL=DEFINITION HREF="26_glo_t.htm#type"><I>type</I></A> <A REL=DEFINITION HREF="e_pkg_er.htm#package-error"><B>package-error</B></A> if any of the <I>symbols</I> to be <I>imported</I> has the <A REL=DEFINITION HREF="26_glo_s.htm#same"><I>same</I></A> <A REL=DEFINITION HREF="26_glo_n.htm#name"><I>name</I></A> (under <A REL=DEFINITION HREF="f_stgeq_.htm#stringEQ"><B>string=</B></A>) as some distinct <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A> (under <A REL=DEFINITION HREF="f_eql.htm#eql"><B>eql</B></A>) already <A REL=DEFINITION HREF="26_glo_a.htm#accessible"><I>accessible</I></A> in the <I>package</I>, even if the conflict is with a <A REL=DEFINITION HREF="26_glo_s.htm#shadowing_symbol"><I>shadowing symbol</I></A> of the <I>package</I>. <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_shadow.htm#shadow"><B>shadow</B></A>, <A REL=DEFINITION HREF="f_export.htm#export"><B>export</B></A> <P>
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<P><B>Notes:</B> None.
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<P>
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<P><HR>The following <A REL=META HREF="../Front/X3J13Iss.htm">X3J13 cleanup issues</A>, <I>not part of the specification</I>, apply to this section:<P><UL><LI> <A REL=CHILD HREF="../Issues/iss194.htm">IMPORT-SETF-SYMBOL-PACKAGE</A><LI> <A REL=CHILD HREF="../Issues/iss254.htm">PACKAGE-FUNCTION-CONSISTENCY:MORE-PERMISSIVE</A><P></UL><HR>
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<A REL=NAVIGATOR HREF="../Front/StartPts.htm"><IMG WIDTH=80 HEIGHT=40 ALT="[Starting Points]" SRC="../Graphics/StartPts.gif" ALIGN=Bottom></A><A REL=TOC HREF="../Front/Contents.htm"><IMG WIDTH=80 HEIGHT=40 ALT="[Contents]" SRC="../Graphics/Contents.gif" ALIGN=Bottom></A><A REL=INDEX HREF="../Front/X_Master.htm"><IMG WIDTH=80 HEIGHT=40 ALT="[Index]" SRC="../Graphics/Index.gif" ALIGN=Bottom></A><A REL=INDEX HREF="../Front/X_Symbol.htm"><IMG WIDTH=80 HEIGHT=40 ALT="[Symbols]" SRC="../Graphics/Symbols.gif" ALIGN=Bottom></A><A REL=GLOSSARY HREF="../Body/26_a.htm"><IMG WIDTH=80 HEIGHT=40 ALT="[Glossary]" SRC="../Graphics/Glossary.gif" ALIGN=Bottom></A><A HREF="../Front/X3J13Iss.htm"><IMG WIDTH=80 HEIGHT=40 ALT="[Issues]" SRC="../Graphics/Issues.gif" ALIGN=Bottom></A><BR>
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<A REL=COPYRIGHT HREF="../Front/Help.htm#Legal"><I>Copyright 1996-2005, LispWorks Ltd. All rights reserved.</I></A><P>
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