Tim: Great info - many thanks for the explanation.
"I just checked wikipedia and it says the Mac SE/30 with 4MB or RAM and 80MB hard drive was $6,569! I don’t remember them being that expensive. Makes the machines today look dirt cheap!" The SE/30 was a great little machine. The PDS card had expansions slots. I don't think I used an accelerator card but I know I had an ethernet card and a video card for my 19" (black and white) CRT monitor. The $6k figure sounds like current dollars but, yes, the Mac was an expensive computer to purchase though the lifecycle cost made it a no brainer purchase. In the past few days, we've seen postings from folks who are using laptops that are 7+ years old that are still being used to write software. -- Douglas von Roeder 949-336-2902 On Thu, Apr 6, 2017 at 3:09 PM, Tim Nevels via 4D_Tech <4d_tech@lists.4d.com > wrote: > On Apr 6, 2017, at 4:43 PM, Douglas von Roeder wrote: > > > A couple of thoughts on this… > > > > I couldn't find this documented but 4D's compiler does three "passes" > > through the source code (when you're not typing all of your variables). > > IIRC, the compiler displays what it's doing for each pass but newer > > versions of 4D + modern hardware are so fast that I haven't seen the > > "label" appear in the compiler window. > > > > For the sake of argument, lets' say that the three passes are something > > like syntax, declarations, and then parameter type matching. There must > be > > no errors in one phase before the compiler will move on to the next. > > Perhaps what you're seeing is that as you resolve errors during the > syntax > > phase, those changes engender issues within that same phase. > > > > Once the issues in the syntax phase are resolved, the compiler will run > the > > declarations phase and will report those errors. > > > > Rinse, lather, repeat for the next phase. > > > > > > Second issue is that 4D's compiler used to scan methods sequentially, > based > > on ID, and would check parameters based on the parameter list that exists > > for the first instance of a method. > > > > This was my observation of the early versions of the compiler so it could > > be observer error/bias and 4D could have completely revamped how the > > compiler functions. Also, in the 25 years or so since I made this > > observation, I've never gone back and checked. :-) > > > > Having just done a 2004 to 15 conversion, I saw the same behavior you're > > experiencing and it was *not* a pleasant feeling. Most of the time I > > compile it really is just a "spell check", so it was unnerving to > compile - > > error fix - compile and get more errors - error fix - compile and get > > different errors. No fun at all but an inherent part of the process of > > "getting to done". > > If you are letting 4D do the variable typing then the first phase is to > scan every method and create a list of all variables and their types. If > you are typing all variables then it first looks at the “Compiler…” methods > for variable typing. > > It also has to type all parameters for methods. So if you let 4D do all > the typing it has to scan all methods looking for $1, $2, etc and types > them. If you are doing the typing then it gets this info from “Compiler…” > methods. > > Then you have local variables to deal with. Could be it builds this typing > list when it is scanning all the methods. Could be during all this typing > scanning it does some syntax checking along the way instead of waiting > until the last step. > > I think the 4D Compiler is very optimized. As it is processing as soon as > an uncertain situation occurs it bails. No need to scan the whole structure > every time if an uncertain situation could have cascading effects. So > that’s why when you fix some errors and compile again you can get a whole > new set of errors you didn’t get the first time. And this explains why > sometimes the number of errors increase with each compile instead of go > down. > > I’m sure it would be extremely difficult to have the compiler show every > possible error when it compiles each time. I think it is doing the best > that it can do and as they say “it is what it is”. > > I wonder whatever happened to the original 4D Compiler writer David Hemmo? > > When he wrote 4D Compiler back in 1990 I thought he was a programming god > to be able to build all that machine code and hook it all together to make > something that actually worked. And then to update 4D Compiler to support > 68K machine code, PPC machine code, Intel machine code, and variances > between Mac OS and Windows OS. To me that is some serious programming skill > and ability. > > I remember the first time I ran 4D Compiler 1.0 on a structure. It had > over 4,000 errors! I worked all day to get that number down to the > hundreds. A lot of code had to be rewritten due to variable retyping > issues. I probably tried to compile 20 times that day. But by the second > day I had a compiled structure that ran on my Mac SE/30. > > I just checked wikipedia and it says the Mac SE/30 with 4MB or RAM and > 80MB hard drive was $6,569! I don’t remember them being that expensive. > Makes the machines today look dirt cheap! > > Tim > > ******************************************** > Tim Nevels > Innovative Solutions > 785-749-3444 > timnev...@mac.com > ******************************************** > > ********************************************************************** > 4D Internet Users Group (4D iNUG) > FAQ: http://lists.4d.com/faqnug.html > Archive: http://lists.4d.com/archives.html > Options: http://lists.4d.com/mailman/options/4d_tech > Unsub: mailto:4d_tech-unsubscr...@lists.4d.com > ********************************************************************** > ********************************************************************** 4D Internet Users Group (4D iNUG) FAQ: http://lists.4d.com/faqnug.html Archive: http://lists.4d.com/archives.html Options: http://lists.4d.com/mailman/options/4d_tech Unsub: mailto:4d_tech-unsubscr...@lists.4d.com **********************************************************************
