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</o:shapelayout></xml><![endif]--></head><body lang=EN-AU link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoPlainText>> <span lang=EN-US style='mso-fareast-language:EN-AU'>-----Original Message-----</span></p><p class=MsoPlainText>> <span lang=EN-US style='mso-fareast-language:EN-AU'>From: Oberon [mailto:oberon-bounces@lists.inf.ethz.ch] On Behalf Of</span></p><p class=MsoPlainText>> <span lang=EN-US style='mso-fareast-language:EN-AU'>Jörg Straube</span></p><p class=MsoPlainText>> <span lang=EN-US style='mso-fareast-language:EN-AU'>Sent: Sunday, 11 November 2018 6:35 PM</span></p><p class=MsoPlainText>> <span lang=EN-US style='mso-fareast-language:EN-AU'>To: ETH Oberon and related systems</span></p><p class=MsoPlainText>> <span lang=EN-US style='mso-fareast-language:EN-AU'>Subject: Re: [Oberon] SYSTEM Modules</span></p><p class=MsoPlainText>> </p><p class=MsoPlainText>> All</p><p class=MsoPlainText>> </p><p class=MsoPlainText>> If I understand your reasoning correctly, you say: I happen to be a</p><p class=MsoPlainText>> low level programmer and am confronted with the fact I have to write</p><p class=MsoPlainText>> a lot of SYSTEM qualifiers in my code. As I don t like that, lets</p><p class=MsoPlainText>> modify the language.</p><p class=MsoPlainText>> </p><p class=MsoPlainText>> Now imagine I happen to be a programmer of a GUI and my code is full</p><p class=MsoPlainText>> of Display qualifiers. I could for sure find a similar procedure as</p><p class=MsoPlainText>> your InitClocks with 30 SYSTEM calls where I use 30 calls to Display</p><p class=MsoPlainText>> procedures in a row.</p><p class=MsoPlainText>> As I don t like that, lets modify the language.</p><p class=MsoPlainText>> </p><p class=MsoPlainText>> In the first case I would propose IMPORT S:=SYSTEM, for the second</p><p class=MsoPlainText>> programmer I would propose IMPORT D := Display</p><p class=MsoPlainText>> </p><p class=MsoPlainText>> I like the Oberon idea of fully qualified names. The Modula syntax</p><p class=MsoPlainText>> where you dequalify your names during the IMPORT by a list of</p><p class=MsoPlainText>> procedures opens up a lot of confusion while maintaing different</p><p class=MsoPlainText>> sources, with different dequalifying IMPORT lists.</p><p class=MsoPlainText>> </p><p class=MsoPlainText>> Just my 2cents </p><p class=MsoPlainText>> J rg</p><p class=MsoPlainText>> </p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><span style='color:black'>Not exactly. I'm questioning why some global built-in procedures have to be qualified whereas others don't. How cumbersome would it be if we had to say GLOBAL.INC(i, 1) or ch := GLOBAL.CHR(i)? The definition of SYSTEM has diminished over time to the point where it is now almost redundant. <o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>Comparing SYSTEM calls to Display calls is like comparing apples to oranges.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>Global built-in / SYSTEM procedures are very different to procedures contained in library or application modules. You cannot necessarily apply the same rules to both. Built-in procedures have one or more of the following attributes:<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText style='margin-left:36.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='color:black'><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='color:black'>Variable number of parameters<o:p></o:p></span></p><p class=MsoPlainText style='margin-left:36.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='color:black'><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='color:black'>Implemented as inline code<o:p></o:p></span></p><p class=MsoPlainText style='margin-left:36.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='color:black'><span style='mso-list:Ignore'>3.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='color:black'>Bypass normal type-checking code<o:p></o:p></span></p><p class=MsoPlainText style='margin-left:36.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='color:black'><span style='mso-list:Ignore'>4.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='color:black'>Bypass normal range-checking code<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>And, above all:<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText style='margin-left:36.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='color:black'><span style='mso-list:Ignore'>5.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='color:black'>They can only be modified / added to by modifying the compiler<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>Whenever I have had a situation where there could be many calls to the same imported module (e.g. Texts, Display) etc, I wouldn’t use aliases just to save typing. <o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>e.g. if I see repetitive code like this<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'> Files.ReadInt(R, data); Out.String("fixP = "); Out.Int(data, 8); Out.Ln();<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'> Files.ReadInt(R, data); Out.String("fixD = "); Out.Int(data, 8); Out.Ln();<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'> Files.ReadInt(R, data); Out.String("fixT = "); Out.Int(data, 8); Out.Ln();<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'> Files.ReadInt(R, data); Out.String("entry = "); Out.Int(data, 8); Out.Ln();<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>I am likely to refactor it to something like this: <o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'> PROCEDURE ShowFixup(r: Files.Rider; label: ARRAY OF CHAR);<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'> VAR<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'> data: INTEGER;<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'> BEGIN<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'> Files.ReadInt(r, data); Out.String(label); Out.String(" = "); Out.Int(data, 8); Out.Ln();<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'> END ShowFixup;<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'> ShowFixup(R, "fixP");<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'> ShowFixup(R, "fixD");<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'> ShowFixup(R, "fixT");<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'> ShowFixup(R, "entry");<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>The dozen references to Out are reduced to four.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>Regards,<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'>Chris Burrows<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'>CFB Software<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><a href="http://www.astrobe.com">http://www.astrobe.com</a><o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p></div></body></html>