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</o:shapelayout></xml><![endif]--></head><body lang=DE-CH link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'>Okay. “Q” and ”T” are not mentioned and will be trapped.<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'>If you know that for ”Q” and “T” the value should be 0 then why not mention them explicitly.<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'> “CASE” is meant as an implementation optimization with a jump table instead of several IFs.<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'>With a jump table you have the in-table cases and the out-of-table case.<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'>Should ELSE cover both or only in-table or only out-of-table?<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'>We really have to see, how many of us did detect that the numeric CASE is not implemented (yet) in ORP.Mod?<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'>I assume there is only a handful (either me as being interested in compiler construction or the very few actually trying to use numeric CASE)<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'>A word to speed benefit: Even if you have - let’s say - 128 case labels you would need only 7 IFs at runtime (with binary division).<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'>So, the benefit of having a jump table is rather small.<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'>Don’t get me wrong: numeric CASE is nice and syntactically pleasing, but how often do you need it?<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'>br<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'>Jörg<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:11.0pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-US style='font-size:11.0pt'><o:p> </o:p></span></font></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><font size=2 face=Calibri><span lang=EN-US style='font-size:11.0pt;mso-fareast-language:DE-CH;font-weight:bold'>From:</span></font></b><span lang=EN-US style='mso-fareast-language:DE-CH'> Oberon [mailto:oberon-bounces@lists.inf.ethz.ch] <b><span style='font-weight:bold'>On Behalf Of </span></b>Chris Burrows<br><b><span style='font-weight:bold'>Sent:</span></b> Friday, February 16, 2018 12:36 PM<br><b><span style='font-weight:bold'>To:</span></b> ETH Oberon and related systems <oberon@lists.inf.ethz.ch><br><b><span style='font-weight:bold'>Subject:</span></b> [Oberon] A CASE quiz<o:p></o:p></span></p></div></div><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-US style='font-size:11.0pt'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt'>I have attached two copies of a CASE statement which implements part of the Soundex algorithm. Assume that both compile OK but both have at least one identical logical error which you may not have noticed if I hadn’t warned you. Which version do you think would be more effective in flushing out the error if the programmer was not aware of his mistake?<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt'>I put my money on the one without the ELSE …<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt;mso-fareast-language:EN-AU'>Regards,<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt;mso-fareast-language:EN-AU'>Chris Burrows<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt;mso-fareast-language:EN-AU'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt;mso-fareast-language:EN-AU'>CFB Software<o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt;mso-fareast-language:EN-AU'><a href="http://www.astrobe.com/RISC5">http://www.astrobe.com/RISC5</a><o:p></o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt;mso-fareast-language:EN-AU'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt'><o:p> </o:p></span></font></p><p class=MsoNormal><font size=2 face=Calibri><span lang=EN-AU style='font-size:11.0pt'><o:p> </o:p></span></font></p></div></body></html>