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<TITLE>CLHS: Section 2.3.4</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="02_cc.htm"><IMG WIDTH=40 HEIGHT=40 ALT="[Previous]" SRC="../Graphics/Prev.gif" ALIGN=Bottom></A><A REL=UP HREF="02_c.htm"><IMG WIDTH=40 HEIGHT=40 ALT="[Up]" SRC="../Graphics/Up.gif" ALIGN=Bottom></A><A REL=NEXT HREF="02_ce.htm"><IMG WIDTH=40 HEIGHT=40 ALT="[Next]" SRC="../Graphics/Next.gif" ALIGN=Bottom></A></H1>
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<H2>
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2.3.4 Symbols as Tokens</H2> <P>
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Any <A REL=DEFINITION HREF="26_glo_t.htm#token"><I>token</I></A> that is not a <A REL=DEFINITION HREF="26_glo_p.htm#potential_number"><I>potential number</I></A>, does not contain a <A REL=DEFINITION HREF="26_glo_p.htm#package_marker"><I>package marker</I></A>, and does not consist entirely of dots will always be interpreted as a <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A>. Any <A REL=DEFINITION HREF="26_glo_t.htm#token"><I>token</I></A> that is a <A REL=DEFINITION HREF="26_glo_p.htm#potential_number"><I>potential number</I></A> but does not fit the number syntax is a reserved <A REL=DEFINITION HREF="26_glo_t.htm#token"><I>token</I></A> and has an <A REL=DEFINITION HREF="26_glo_i.htm#implementation-dependent"><I>implementation-dependent</I></A> interpretation. In all other cases, the <A REL=DEFINITION HREF="26_glo_t.htm#token"><I>token</I></A> is construed to be the name of a <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A>. <P>
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Examples of the printed representation of <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbols</I></A> are in the next figure. For presentational simplicity, these examples assume that the <A REL=DEFINITION HREF="26_glo_r.htm#readtable_case"><I>readtable case</I></A> of the <A REL=DEFINITION HREF="26_glo_c.htm#current_readtable"><I>current readtable</I></A> is <TT>:upcase</TT>. <P>
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<PRE>
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FROBBOZ The <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> whose <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is FROBBOZ.
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frobboz Another way to notate the same <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A>.
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fRObBoz Yet another way to notate it.
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unwind-protect A <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> with a hyphen in its <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A>.
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+$ The <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> named +$.
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1+ The <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> named 1+.
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+1 This is the <A REL=DEFINITION HREF="26_glo_i.htm#integer">integer</A> 1, not a <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A>.
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pascal_style This <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> has an underscore in its <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A>.
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file.rel.43 This <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> has periods in its <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A>.
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\( The <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> whose <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is (.
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\+1 The <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> whose <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is +1.
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+\1 Also the <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> whose <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is +1.
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\frobboz The <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> whose <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is fROBBOZ.
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3.14159265\s0 The <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> whose <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is 3.14159265s0.
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3.14159265\S0 A different <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A>, whose <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is 3.14159265S0.
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3.14159265s0 A possible <A REL=DEFINITION HREF="26_glo_s.htm#short_float">short float</A> approximation to <PI>.
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</PRE>
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<P><B>Figure 2-15. Examples of the printed representation of symbols (Part 1 of 2)</B> <P>
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<PRE>
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APL\\360 The <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> whose <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is APL\360.
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apl\\360 Also the <A REL=DEFINITION HREF="26_glo_s.htm#symbol">symbol</A> whose <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is APL\360.
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\(b^2\)\-\4*a*c The <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is (B^2) - 4*A*C.
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Parentheses and two spaces in it.
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\(\b^2\)\-\4*\a*\c The <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is (b^2) - 4*a*c.
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Letters explicitly lowercase.
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|"| The same as writing \".
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|(b^2) - 4*a*c| The <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is (b^2) - 4*a*c.
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|frobboz| The <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is frobboz, not FROBBOZ.
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|APL\360| The <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is APL360.
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|APL\\360| The <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is APL\360.
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|apl\\360| The <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is apl\360.
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|\|\|| Same as \|\| ---the <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is ||.
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|(B^2) - 4*A*C| The <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is (B^2) - 4*A*C.
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Parentheses and two spaces in it.
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|(b^2) - 4*a*c| The <A REL=DEFINITION HREF="26_glo_n.htm#name">name</A> is (b^2) - 4*a*c.
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</PRE>
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<P><B>Figure 2-16. Examples of the printed representation of symbols (Part 2 of 2)</B> <P>
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In the process of parsing a <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A>, it is <A REL=DEFINITION HREF="26_glo_i.htm#implementation-dependent"><I>implementation-dependent</I></A> which <A REL=DEFINITION HREF="26_glo_i.htm#implementation-defined"><I>implementation-defined</I></A> <A REL=DEFINITION HREF="26_glo_a.htm#attribute"><I>attributes</I></A> are removed from the <A REL=DEFINITION HREF="26_glo_c.htm#character"><I>characters</I></A> forming a <A REL=DEFINITION HREF="26_glo_t.htm#token"><I>token</I></A> that represents a <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A>. <P>
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When parsing the syntax for a <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A>, the <A REL=DEFINITION HREF="26_glo_l.htm#lisp_reader"><I>Lisp reader</I></A> looks up the <A REL=DEFINITION HREF="26_glo_n.htm#name"><I>name</I></A> of that <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A> in the <A REL=DEFINITION HREF="26_glo_c.htm#current_package"><I>current package</I></A>. This lookup may involve looking in other <A REL=DEFINITION HREF="26_glo_p.htm#package"><I>packages</I></A> whose <A REL=DEFINITION HREF="26_glo_e.htm#external_symbol"><I>external symbols</I></A> are inherited by the <A REL=DEFINITION HREF="26_glo_c.htm#current_package"><I>current package</I></A>. If the name is found, the corresponding <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A> is returned. If the name is not found (that is, there is no <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A> of that name <A REL=DEFINITION HREF="26_glo_a.htm#accessible"><I>accessible</I></A> in the <A REL=DEFINITION HREF="26_glo_c.htm#current_package"><I>current package</I></A>), a new <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A> is created and is placed in 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 <A REL=DEFINITION HREF="26_glo_c.htm#current_package"><I>current package</I></A> becomes the owner (<A REL=DEFINITION HREF="26_glo_h.htm#home_package"><I>home package</I></A>) of the <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A>, and the <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A> becomes interned in the <A REL=DEFINITION HREF="26_glo_c.htm#current_package"><I>current package</I></A>. If the name is later read again while this same <A REL=DEFINITION HREF="26_glo_p.htm#package"><I>package</I></A> is current, the same <A REL=DEFINITION HREF="26_glo_s.htm#symbol"><I>symbol</I></A> will be found and returned. <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/iss027.htm">CHARACTER-PROPOSAL:2-1-1</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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