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93 lines
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<H2>Issue DEFGENERIC-DECLARE Writeup</H2>
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<PRE><B>Issue:</B> <A HREF="iss100.htm">DEFGENERIC-DECLARE</A><P>
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<P>
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<B>References:</B> 88-002R p.2-27<P>
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<P>
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<B>Category:</B> ADDITION<P>
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<P>
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<B>Edit history:</B> 29-Apr-90, Version 1 by Moon<P>
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30-Apr-90, Version 2 by Moon (update current practice)<P>
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<P>
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<B>Problem description:<P>
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</B><P>
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<A REL=DEFINITION HREF="../Body/m_defgen.htm#defgeneric"><B>DEFGENERIC</B></A> only allows <A REL=DEFINITION HREF="../Body/s_declar.htm#declare"><B>DECLARE</B></A> to appear once, which is inconsistent with<P>
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<A REL=DEFINITION HREF="../Body/m_defun.htm#defun"><B>DEFUN</B></A>, which allows any number of DECLAREs.<P>
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<P>
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This is Symbolics issue #23.<P>
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<P>
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<B>Proposal (DEFGENERIC-DECLARE:ALLOW-MULTIPLE):<P>
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</B><P>
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Allow the <A REL=DEFINITION HREF="../Body/s_declar.htm#declare"><B>DECLARE</B></A> option to appear multiple times in a <A REL=DEFINITION HREF="../Body/m_defgen.htm#defgeneric"><B>DEFGENERIC</B></A> form.<P>
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The multiple declarations are appended together.<P>
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<P>
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<B>Rationale:<P>
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</B><P>
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Programmers rely on the syntactic analogy between <A REL=DEFINITION HREF="../Body/m_defgen.htm#defgeneric"><B>DEFGENERIC</B></A> and <A REL=DEFINITION HREF="../Body/m_defun.htm#defun"><B>DEFUN</B></A>.<P>
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<P>
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Note that some implementations allow several implementation-dependent<P>
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declarations in <A REL=DEFINITION HREF="../Body/m_defgen.htm#defgeneric"><B>DEFGENERIC</B></A>, so the list of declarations in a <A REL=DEFINITION HREF="../Body/m_defgen.htm#defgeneric"><B>DEFGENERIC</B></A><P>
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could be quite long.<P>
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<P>
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<B>Current practice:<P>
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</B><P>
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Symbolics Genera 8.0 only allows <A REL=DEFINITION HREF="../Body/s_declar.htm#declare"><B>DECLARE</B></A> to appear once.<P>
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Lucid 4.0.0 Beta-1 allows <A REL=DEFINITION HREF="../Body/s_declar.htm#declare"><B>DECLARE</B></A> to appear multiple times.<P>
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<P>
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<B>Cost to Implementors:<P>
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</B><P>
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Easy.<P>
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<P>
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<B>Cost to Users:<P>
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</B><P>
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None.<P>
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<P>
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<B>Cost of non-adoption:<P>
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</B><P>
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<A REL=DEFINITION HREF="../Body/m_defgen.htm#defgeneric"><B>DEFGENERIC</B></A> would be inconsistent with all other forms that allow <A REL=DEFINITION HREF="../Body/s_declar.htm#declare"><B>DECLARE</B></A><P>
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to be used to specify declarations.<P>
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<P>
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<B>Performance impact:<P>
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</B><P>
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None.<P>
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<P>
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<B>Benefits:<P>
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</B><P>
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More consistent language.<P>
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<P>
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<B>Esthetics:<P>
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</B><P>
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More consistent language.<P>
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<P>
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<B>Discussion:<P>
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</B><P>
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None.<P>
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</PRE>
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