World: r4wp
[#Red] Red language group
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Kaj 17-Jun-2013 [8480] | It's confusing, yes, but it's typical C code. And it's by the holy Knuth, so you can't question it ;-) |
Arnold 17-Jun-2013 [8481] | Time for the Red rebolution to improve the readability of software. I have been playing with the Mersenne Twister code, from C to Red/System. There is no unsigned integer in Red/System? |
Kaj 17-Jun-2013 [8482x2] | No, just integer! |
If you use it as unsigned, you have to check very carefully what you're doing with the highest bit | |
Arnold 17-Jun-2013 [8484] | Unsined integers is on the wish-list for Red/System v2 https://github.com/dockimbel/Red/wiki/Red-System-v2-Wish-List point 29 |
DocKimbel 17-Jun-2013 [8485x3] | You can always have an unsigned integer using a simple pointer. |
Also, "unsigned" is just a convention, the data is same as the signed version. | |
As Kaj said, you can achieve the same calculation with signed integers, you just need to be careful. | |
Maxim 17-Jun-2013 [8488x2] | one question for Red/System. can it already, ( or is it planned ) to export static libs for use within (C/C++, other?) compiler/linkers? |
this would be an nice way for users to try red and progressively replace their binary code base, one source file at a time... instead of a whole project at once. | |
Kaj 17-Jun-2013 [8490] | Yes, not yet, but it's in the roadmap. Currently, you can replace a project one shared library at a time, or one 0MQ service at a time |
DocKimbel 18-Jun-2013 [8491x3] | I have a new test pre-release version for Android, could some of you test it on different devices? http://static.red-lang.org/hello2.apk |
It should display an input field and a "Do" button, allowing you to evaluate arbitrary Red code. The result of evaluation scrolls up, below the button. | |
On Nexus4, it doesn't run. I would like to see how it reacts on other 4.x devices and also older ones. It runs fine on my HTC 2.3.5. | |
Bo 18-Jun-2013 [8494] | On my Motorola XT881 running 4.1.2, Red opens and then immediately closes again. |
DocKimbel 18-Jun-2013 [8495] | Thanks Bo. Anyone with a 4.0.x device? |
XieQ 18-Jun-2013 [8496x2] | It runs fine on my Motorola ME525+ 2.3.6, but can't use PRINT, is that OK? |
And on my ONDA Pad 4.1.1, it's opens and then immediately closes again. | |
DocKimbel 18-Jun-2013 [8498x3] | The printing is redirected to the logcat. To see it, you need a logcat viewer like eLogcat from PlayStore. |
I just remembered that I bought a few months ago a cheap Android 4.1 USB stick, I will look at the 4.x issues tomorrow. | |
When we'll have a true Red console emulation for Android, we'll be able to redirect the printing functions back to the console. | |
AdrianS 18-Jun-2013 [8501] | The .apk wouldn't install on my Galaxy Nexus with 4.2.2. |
GrahamC 18-Jun-2013 [8502] | Curious it installed on my N7 |
Pekr 18-Jun-2013 [8503x2] | runs on my htc sensation 4.0.1 |
the only strange thing - the evaluator, when I mistakenly put: 1 + t = 1 | |
DocKimbel 19-Jun-2013 [8505] | Ah, so it's HTC-friendly it seems. :-) |
Arnold 19-Jun-2013 [8506] | t=0 |
Pekr 19-Jun-2013 [8507] | I did not define 't, expected error being raised ... |
Arnold 19-Jun-2013 [8508] | so, it solved the equation! Pretty smart thing. |
DocKimbel 19-Jun-2013 [8509] | Actually, you got an error message sent to your logcat. :-) Once things will be stabilized for 4.x support, I'll redirect printing to the GUI. |
Endo 19-Jun-2013 [8510] | It works on Samsung S3 Galaxy, Android 2.3.6 |
DocKimbel 19-Jun-2013 [8511] | I've reproduced the 4.x issue on my Rikomagic USB stick. |
Arnold 19-Jun-2013 [8512] | Login on SO requires a OpenID account. Don't want to link all my info on the web. SO is over for me. |
Pekr 19-Jun-2013 [8513] | I don't have OpenID, yet I am using SO, is it really a necessity? |
Maxim 19-Jun-2013 [8514] | AFAIK you can create an account just for SO |
Arnold 19-Jun-2013 [8515x2] | I have an account on Wordpress.com lying around, even can login to Wpress, but SO says "You don't own that identity" :( |
creating a separate account | |
Arnold 20-Jun-2013 [8517] | The deobfuscating Knuth's random program project is progressing into its final stage. It turned out that with getting the results of the program the same only the first part of the puzzle got solved. To use it in real programs you use the provided ran_arr_next function. This involved some pointer aritmetic that is not 100% supported by Red/System. I finally got the function to produce the same results as the C version. The downside is it is now quite a mess with pointer indeces and other variables, so a lot of cleaning up to do and/or rework only using the index on the array approach. |
DocKimbel 20-Jun-2013 [8518] | This involved some pointer aritmetic that is not 100% supported by Red/System. What is it lacking precisely? |
Arnold 20-Jun-2013 [8519] | It is just slightly different. The possibility to go back to the first element of the array or store that address. :(ran_arr_buf/1) would make it a lot easier. I already had a lot of help from Peter on this (thumbs up!) and I made good progress by now. I get the pointer of the array and I can go up and down using + and -, this works great, and the pointer is going along with it then and I suspect that if I do ptr: ran_arr_buf and I progress ran_arr_buf by 1 that I progress ptr too. I now kinda solved it by using an additional variable. When I reach a 100, I subtract 100 from the array ran_array_buf to go back. Tonight and tomorrow I have some time to clean up my code and I can experiment some more. It is proven it can be done, but keeping the extra variable is surely slowing down compared to C's pure pointer solution. |
DocKimbel 20-Jun-2013 [8520] | I suspect that if I do ptr: ran_arr_buf and I progress ran_arr_buf by 1 that I progress ptr too. That's a wrong assumption. Those two variables are distincts, so each one has its own memory slot. If you change one, that has no effect on the other. What is shared there is the pointed memory region. So, if you change ran_arr_buf/value, that will affect ptr/value (they both point to the same memory location). |
Arnold 20-Jun-2013 [8521x3] | my trouble seems to arise from the different roles the array and the pointer play in the C code vs the Red/System code. In C the pointer is used as indicator for initialisation and signals when a kind of reshuffle is required and it points to the next generated value. In Red/System the array points to the current/next value and a pointer is not needed, and you can no longer use it as before to signal the status. This complicates things in this case. |
Oh nice effect. array1: 1 2 3 4 5 m: 2 ;;print array/m ;; 2 array1: array1 + 2 ;;print array/m ;; 5 it is tricky to move the array pointer around, beware of the dog ;) | |
sorry 5 has to be 4 in that example. | |
DocKimbel 20-Jun-2013 [8524x2] | You seem quite confused about pointers in Red/System. 1) There's no "array" as distinct entity in Red/System, but you have indexed access, so you can "simulate" arrays to some extent. 2) "In C the pointer is used as indicator for initialisation and signals when a kind of reshuffle is required and it points to the next generated value." I don't understand this sentence, you should stick to C terminology (terms like "signals", "reshuffle" and "generated value" are alien to me in a C language context). 3) "In Red/System the array points to the current/next value and a pointer is not needed, and you can no longer use it as before to signal the status." I don't understand this one either... There's no array, only pointers. "to signal the status" has no meaning to me...sorry. |
I think you have a complicated mental representation of what pointers and arrays are in C and Red/System. It's simpler and more straightforward than your descriptions. Basically, Red/System pointers act the same way as C ones (including "array" support). The only difference is the base for indexed accesses (1 vs 0). | |
Kaj 20-Jun-2013 [8526x4] | Arnold, what you call :(ran_arr_buf/1) is possible and is just |
:ran_arr_buf | |
Sorry, even simpler: | |
ran_arr_buf | |
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