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Forum Index : Microcontroller and PC projects : CMM2: Frustration with arrays....
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| mkopack73 Senior Member  Joined: 03/07/2020 Location: United StatesPosts: 261 |
Ok, I'm once again going to voice my frustration with the way arrays are created in this version of BASIC.... I'm trying to come up with a way to make reusable library code that will work regardless of which way the main (calling) program sets OPTION MODE. Yes I can use the BOUND command to understand the upper and lower array indexes of the array - that's not the problem. The problem is in defining the arrays themselves... In OPTION MODE 0 if I want an array to hold 10 elements I have to do: dim integer myarray(9) = (1,2,3,4,5,6,7,8,9,10) (WHY THE HELL IS IT 9?!?!? I'm putting 10 items into the array!!!! MAKES NO SENSE AT ALL) In OPTION MODE 1 if I want the array to hold 10 elements I have to do: dim integer myarray(10)= (1,2,3,4,5,6,7,8,9,10) Shouldn't the dim integer myarray() take the SIZE, not the MAX INDEX count???? Also, since there's no way to know which way the OPTION MODE is set before I create the array, I have no way to know which version I should use... Can we either: 1) standardize the value that goes in the array dimension to be the SIZE of the array (# of elements, regardless of the indexing scheme - so for my example above they BOTH would get set to 10) or 2) get an MM.INFO(MODE) that will return either a 0 or 1 so we can ask which way the MODE is set??? Was the whole dimension taking the last index a hold over from MS's later versions of BASIC that switched to 0 indexing? Because I've never seen a single version of BASIC that did it based on last index rather than the size of the array... |
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| matherp Guru  Joined: 11/12/2012 Location: United KingdomPosts: 10310 |
The handling of arrays is exactly the same as all other versions of MMBasic. It ain't going to change. |
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| mkopack73 Senior Member Joined: 03/07/2020 Location: United StatesPosts: 261 |
Still seems weird to me... If that's the case, can we at least get an MM.INFO(MODE) function that would give us what the current mode is set to so we can at least know what way the mode is set so we can create the array properly based on the mode? Otherwise, reusable / portable code involving arrays is pretty much dead on arrival... |
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thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4311 |
Umm, not in front of my CMM2, but ... Function array_mode() Local a(2) array_mode = Bound(a, 0) End Function MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4311 |
... though I would agree that it would be comforting if all OPTIONs were queryable in a uniform manner. MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| mkopack73 Senior Member Joined: 03/07/2020 Location: United StatesPosts: 261 |
Edit: just looked at what you did more closely - yes I could do something like that but that's an ugly hack workaround.. If I do OPTION MODE 0 And then try to create my array with values in it (let's say I want to store 10) dim myarray(9) = (1,2,3,4,5,6,7,8,9,10) If OPTION MODE 1 is set and I use the same line of code I'll get a dimension size error (because it's only allocating 9 cells in the array but trying to put 10 in). If I do it the other way around: dim myarray(10) = (1,2,3,4,5,6,7,8,9,10) This will work fine for OPTION MODE 1, but in OPTION MODE 0 I'll likewise get a dimension size error because it's expecting 11 items to be specified. (which seems dumb to me, but whatever, fine it's not going to get changed...) There's currently no way to know which way OPTION MODE is set to, so no way for my library code to know which value to set the array size to to make it work in both cases... I have no way to know which way the calling program has it defined. At least if there was an MM.INFO(MODE) type function then I could at least do something like: dim size% if (MM.INFO(MODE)=0) then size% = 9 else size% = 10 endif dim myarray(size%) = (1,2,3,4,5,6,7,8,9,10) Which would work in both OPTION MODE settings... Edited 2020-09-12 00:58 by mkopack73 |
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| matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 10310 |
Thwill's function does exactly what want. Just include a call at the top of your code and then you know how the option base is set |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4311 |
You may also be able to do this: Dim myarray(num_elements%(10)) = (1,2,3,4,5,6,7,8,9,10) Function num_elements%(i%) num_elements% = i% If array_mode%() = 0 Then num_elements% = num_elements% - 1 End Function Function array_mode%() Local a%(2) array_mode% = Bound(a%, 0) End Function Though I would probably cache the result of calling array_mode%() in a global variable. Happy hacking, Tom Edited 2020-09-12 01:22 by thwill MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| mkopack73 Senior Member Joined: 03/07/2020 Location: United StatesPosts: 261 |
Tom, any objections to me putting that code in my "reusable code" guide ? |
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CircuitGizmos Guru Joined: 08/09/2011 Location: United StatesPosts: 1427 |
 Micromites and Maximites! - Beginning Maximite |
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| mkopack73 Senior Member Joined: 03/07/2020 Location: United StatesPosts: 261 |
BTW, I also did a little test to see if it was significantly slower to ask the array for it's bounds (like during a for loop) vs getting the bounds once and storing them in variables and then using the variables for setting the for loop index bounds... It turns out they're so close in time (I did this over an array of size 100,000) that I wouldn't even bother worrying about it. Just put the bounds requests right in the for loop lower + upper index bounds... I did this test because I was concerned that it would perform the bound() call on every iteration through the loop to see if the current index value was > than the upper bound (like it would if we were in C++ or Java) but looks like in MMBASIC it only grabs the values for the lower and upper for loop values once when declaring the loop. |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4311 |
No objections from me. Best wishes, Tom MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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TassyJim Guru Joined: 07/08/2011 Location: AustraliaPosts: 6283 |
I prefer to not assume either BASE 0 or BASE 1. By filling the array after declaring, you can usually just ignore element zero. Sometimes the old fashioned way is best. If I am trying to code for both eventualities, I would prefer 'element 7' to be the same for both. There are some functions where the BASE is significant, but not many and they may require the BASE to be fixed. OPTION BASE 0 ' mysub FOR n = 1 TO 10 PRINT testarray(n) NEXT n END SUB mysub DIM testarray(10) RESTORE mysubdata FOR n = 1 TO 10 READ testarray(n) NEXT n mysubdata: DATA 1,2,3,4,5,6,7,8,9,10 END SUB works the same with OPTION BASE 1 Jim VK7JH MMedit |
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| mkopack73 Senior Member Joined: 03/07/2020 Location: United StatesPosts: 261 |
Sure, but now you're both 1) wasting a cell 2) leaving the potential for unintended consequences because you might not use it but somebody else using your code might use it not realizing that you intended it to stay empty... |
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CaptainBoing Guru Joined: 07/09/2016 Location: United KingdomPosts: 2170 |
No you don't. if you want elements numbered 1 to 10, DIMimg x(10) just do it. It will work in any OPTION BASE. Just ignore (0). You are over thinking this. Do not fall into the trap of "wasting". you have half a meg to play with. If you are worried about a few bytes unused, you had batter stop using . in your comments, spaces before or after ' etc. p.s. this is the same in every basic I have ever used Edited 2020-09-13 03:13 by CaptainBoing |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4311 |
But whatever you do, do not SORT the array or that zero value hiding in element 0 will bite you in the arse. Kind regards, Tom MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4311 |
True of most MMBasics, but I do not believe it applies to the CMM2 which tokenises the BASIC before loading it onto the flash (or equivalent if using OPTION RAM). Tom MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| mkopack73 Senior Member Joined: 03/07/2020 Location: United StatesPosts: 261 |
Coming to realize that there are 2 very different groups here... Those who do professional development and those who don't.... Edit: Or rather I should say, those who have formal software engineering computer science educations and those who don't... Edited 2020-09-13 06:04 by mkopack73 |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4311 |
Those are fighting words partner  I'm sure there are several different groups here, but the primary split is probably between the long term residents with a background in electronics, microcontroller programming and firmware vs. the upstarts  with a background in application programming.I'm sure we can all get along and learn from each other. Also worth remembering that it is the first group that generates the toys that the second group can then use to show-off. YMMV, Tom Edited 2020-09-13 06:09 by thwill MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| lizby Guru Joined: 17/05/2016 Location: United StatesPosts: 3378 |
Indeed. Or those who have no computer science education but a software applications developer / systems analyst / tech writer background starting in 1970 and hardware tinkering since 1977. Writing code in C since before a good many on here were born, but for hobby electronics, preferring BASIC. There are many quite experienced hardware and software people on this site, including some who started when formal training was pretty skimpy. Besides, as Dogberry says, "Comparisons are odorous". If working in BASIC, "formal software engineering computer science education" purists are pretty much self-excluding. ~ Edited 2020-09-13 06:58 by lizby PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed |
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