World: r3wp
[!REBOL3]
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Henrik 20-Apr-2010 [2166x4] | And Pekr is using binaries, because they happen to sort of fit into binary operations in some cases, which makes them look incomplete. |
How about a base! datatype, which would be a number! ? #(10000000)2 == 127 Quick and probably bad example. An issue would be how to convert between different bases. | |
whoops, 128, it should read. | |
pardon my basic binary skills. :-) | |
Anton 20-Apr-2010 [2170] | I would prefer less syntax, if possible, maybe something like 2_10000000 (Remember we have 2#{10000000}, but it's a binary! of course.) |
Pekr 20-Apr-2010 [2171] | Anton - insane is just that ... insane :-) It is just word. I did not say Carl, BrianH or anyone else is insane, having some arguments. REBOL is not religion, as Brian says ... it is a tool. And I want the tool to work correct way, if possible. So - stop being stressed about someone claiming something is insane :-) The question to all above is - what is the correct behaviour. The qeustion even is - what is correct about correctness? I know from the past, that Carl really cares about simple things being simple. I can't remember the case, but I do remember I pointed out something will confuse ppl, and I was right - we could see the same kind of questions by novice again, and again, and again. I think that if you claim, that to-integer #{8000} allow many interpretations, how is that we have choosen the concrete one? (32768) Because it is what we would expect. You might think that I don't understand what BrianH or Max or You talk about. Whereas only Ladislav got the correct answer for me - if it would hurt to have reverse padded OR operation. |
BrianH 20-Apr-2010 [2172] | The behavior was what I expected, so clearly expectations vary :) |
Pekr 20-Apr-2010 [2173x2] | Steeve: I understand your example, no problem about it, but try to adapt it to my (non-existant yet :-) possible R3 cell phone implementation, which will use 32 bit integers (not sure if it would ever happen). Then, if you want your code being cross platform, your code complicates, no? >>(skip to-binary 1022 6) or #{8000} ==#{8324} |
Andreas - thanks for reminding me we have following form: >> l: 2#{11111110} == #{FE} >> print l #{FE} I just wanted to ask, if it would be possible for interpreter to "preserve" original written format for the output purposes? | |
BrianH 20-Apr-2010 [2175x2] | It might help to have an entry in system/catalog or something that says the length of integers in bytes. Or you could just make your own local constant using like this: >> int-size: length? to-binary 1 == 8 |
Then you can use the constant to make your code portable. | |
Pekr 20-Apr-2010 [2177x2] | BrianH: I know :-) It is just that for the simple purpose of OR, you have to do all those conversions and tests for the integer size. Then original "shortcut" format of #{8000} be better avoided in the code. |
is there possibility we would have 'pad function in REBOL, native, which in the case of binary would auto-padd it to the "full format"? :-) | |
BrianH 20-Apr-2010 [2179x2] | When I am adapring code from languages with C-like integer syntax I resolve the constants to regular integers ahead of time and then put the original syntax in comments. Works great, no conversion overhead at runtime. You should try it. |
A PAD function would be useful. | |
Pekr 20-Apr-2010 [2181] | I think we tried some 'pad efforts in the past, but that function gets easily complicated, as far as our expectations might go ... |
BrianH 20-Apr-2010 [2182x2] | But PAD would obviously not be for autopadding, it would be for explicit padding. Don't make the interpreter attempt to read your mind :) |
We made a MOVE function to resolve such discussions, we can do the same with PAD. | |
Pekr 20-Apr-2010 [2184] | Is there a reason, why 'shift (as opposed to R2), does not allow binary as an argument? |
BrianH 20-Apr-2010 [2185] | SHIFT in R3 is a lower-level, much faster function. No other particlar reason though. |
Pekr 20-Apr-2010 [2186] | My question basicall was, if it would work with new binary represenation in R3. I think that there should be no reason to not to. We could add CC ticket for it, if not already there ... |
BrianH 20-Apr-2010 [2187x4] | Go ahead. It's not already there, afaik. |
SHIFT in R3 is a pure function though, non-modifying. You might be better off with a different function for binaries. | |
The changes to SHIFT are a good model for how to make PAD simple: Builder function, positive to pad left, negative to pad right, padding value required, maybe an /into option. Make it simple enough and it could be fast even as a mezzanine. | |
We might want to reverse that positive/negative thing though since SHIFTing left is really padding right with bits though. | |
Ladislav 20-Apr-2010 [2191] | Pekr: "if you want your code being cross platform, your code complicates" - certainly! In such cases, left-padding does not work reliably, in fact! |
Pekr 20-Apr-2010 [2192] | Hmm, because I can't do shift on binary, enbase/base is giving me following result (understandable, as to-binary creates 64 bit binary) >> enbase/base to-binary shift to-integer (copy l) -8 2 == {0000000000000000000000000000000000000000000000000000000010000011} whereas: >> enbase/base 2#{11110000} and 2#{10110000} 2 == "10110000" Correct too? So when using shift, I need to use different scenarios, if I want bits represenation (copy/part)? |
Ladislav 20-Apr-2010 [2193x2] | Example: >> to integer! #{FFFFFFFF} == 4294967295 |
(while you migth want to obtain -1) | |
BrianH 20-Apr-2010 [2195] | Preconversion is usually the best bet for this kind of thing. |
Pekr 20-Apr-2010 [2196] | Ladislav - interesting. So I better first check, what platform (integer-side wise) I am running on, and adjust accordingly? E.g. >> 8 * length? to-binary -1 == 64 |
Ladislav 20-Apr-2010 [2197] | Yes, e.g. your #{8000} may in fact be interpreted as -32768 |
BrianH 20-Apr-2010 [2198] | Yup. And remember that all of those TO-BINARY calls and binary constants have overhead, so you should precompute constants whenever you can. This makes yor code *much* faster. |
Ladislav 20-Apr-2010 [2199] | (as it was in 8-bit CPUs) |
BrianH 20-Apr-2010 [2200] | 16bit |
Pekr 20-Apr-2010 [2201] | We still use 8-bit CPUs, it is just I don't expect REBOL to run on them :-) |
Ladislav 20-Apr-2010 [2202] | They were called 8-bit, AFAIK, but worked with 16-bit integers |
BrianH 20-Apr-2010 [2203x2] | That's the 8088 and its like. Real 8bit CPUs worked in bytes. |
I worked on CPM and DOS 1, so I know the difference :) | |
Ladislav 20-Apr-2010 [2205] | I meant e.g. http://en.wikipedia.org/wiki/Intel_8080 |
BrianH 20-Apr-2010 [2206x2] | (worked on in this case not meaning developing the OSes, but developing *on* the OSes) |
The 8bit vs. 16bit thing as most understand it referred to address space, not integer size :) | |
Pekr 20-Apr-2010 [2208] | The same was with Amiga and Motorola, just reverse, no? MC68000 was 32bit CPU with 16bit bus, whereas adress space and registers were 32bit? |
Ladislav 20-Apr-2010 [2209] | Actually, I remember MC68000 being called 16-bit processor (which is analogical as for I8080, mentioning the bus size, not the address space, or the integer size) |
BrianH 20-Apr-2010 [2210] | Ah, the good old days :) |
Ladislav 20-Apr-2010 [2211] | :-D |
Henrik 20-Apr-2010 [2212] | Anton, that might be a good syntax. A "shame" that x is already taken for pairs. |
Pekr 20-Apr-2010 [2213] | Henrik - I just wanted to say the same (re "x") ... I thought about "*", but not sure ... |
BrianH 20-Apr-2010 [2214] | I prefer to think that "shame" was put in quotes sarcastically :) |
amacleod 20-Apr-2010 [2215] | From R3 twitter: The first R3 embedded extension function evaluated! I think many of you are going to like this capability. |
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