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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;mso-fareast-language:EN-US'>LOOP: R.I.P<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;mso-fareast-language:EN-US'><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;mso-fareast-language:EN-US'>Even the main Oberon loop (you know, the one that never ends :-) is programmed with<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;mso-fareast-language:EN-US'>REPEAT<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;mso-fareast-language:EN-US'> …<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;mso-fareast-language:EN-US'>UNTIL FALSE<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;mso-fareast-language:EN-US'><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;mso-fareast-language:EN-US'>Jörg<o:p></o:p></span></font></p><p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN-US style='font-size:12.0pt;mso-fareast-language:EN-US'><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;font-family:"Calibri",sans-serif;font-weight:bold'>From:</span></font></b><font size=2 face=Calibri><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'> Oberon [mailto:oberon-bounces@lists.inf.ethz.ch] <b><span style='font-weight:bold'>On Behalf Of </span></b>Bob Walkden<br><b><span style='font-weight:bold'>Sent:</span></b> Montag, 14. November 2016 20:35<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> Re: [Oberon] Tidyness of iteration.<o:p></o:p></span></font></p></div></div><p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><o:p> </o:p></span></font></p><div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal><font size=3 color=black face="Times New Roman"><span style='font-size:12.0pt;color:black'>(One must wonder about discarding REPEAT and WHILE and retaining LOOP with<br><br></span></font><o:p></o:p></p></blockquote><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal><font size=3 color=black face="Times New Roman"><span style='font-size:12.0pt;color:black'>strictly one EXIT.)</span></font><o:p></o:p></p></blockquote></blockquote><p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><o:p> </o:p></span></font></p></div><div><p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>Er, definitely not. The read-ahead technique is very valuable in structuring the software to match the structure of the input stream. It's a key technique in Jackson Structured Programming, for example. It makes code a lot easier both to write and, perhaps more importantly, to read and understand. I can't tell you the number of programs over the years that I've had to deal with where the programmer didn't understand this and consequently ended up with a buggy, difficult-to-maintain mess.<o:p></o:p></span></font></p></div><div><p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><o:p> </o:p></span></font></p></div><div><p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>The programming language RPGIII, at least when I used it in the 90s, had by default an automatic outer loop structure and you determined your position in the structure by means of bit-flags. It led to some really messy code, which although quick to write (partly because of in-built DB2) was difficult to support. Especially at 3:30 on a Sunday morning over a telephone dial-up.<o:p></o:p></span></font></p></div><div><p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><o:p> </o:p></span></font></p></div><div><p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>If any of those are to be discarded, let it be LOOP, which encourages badly-structured code.<o:p></o:p></span></font></p></div><div><p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><o:p> </o:p></span></font></p></div><div><p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>B <o:p></o:p></span></font></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt'><font size=3 face="Times New Roman"><span style='font-size:12.0pt'><o:p> </o:p></span></font></p></div></div></body></html>