World: r4wp
[Rebol School] REBOL School
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DocKimbel 22-Mar-2013 [1802] | I agree that the name "closure" is not user-friendly. Also, I wonder if it shouldn't be the default function constructor (also thinking loud for Red). I'm still unsure about that though. |
Gregg 22-Mar-2013 [1803] | Certainly the series copy trap is the one beginners will fall into most. Higher order functions won't be in their code, probably until they are comfortable with 'closure. |
Ladislav 22-Mar-2013 [1804] | ...but the GUI example should be in the repertoire of beginners, don't you think? (and it even "caught" Cyphre, so he asked me how to do it properly using function, so I had to tell him: "don't") |
Gregg 22-Mar-2013 [1805x2] | Agreed with both of you on naming. Now is the time to consider what to change in R3 and what to use in Red. 'Closure has meaning beyond Ladislav's current examples. Do we name things for new users and novices, or experts? For me, name things clearly, and supplement with docs if the names don't match expectation. |
On the GUI, yes, perhaps. | |
DocKimbel 22-Mar-2013 [1807] | The "series copy trap" is what makes me hesitate about making closures the default function constructor. I think it should not be a "trap" in the first place, it is just undocumented, while it should IMHO be very clearly explained in the series chapter. Understanding how literal series behave is an important step in understanding Rebol. |
Gregg 22-Mar-2013 [1808] | Doc +1 |
Ladislav 22-Mar-2013 [1809] | In this case "function" obviously does not match expectation, while "closure" matches expectation for "function", otherwise looking too "scary" to provoke some of its own. |
Gregg 22-Mar-2013 [1810x2] | Yes. The question for me is why function doesn't work, since I haven't done any R3 GUIs yet. |
That is, do we address it in the implementation or naming (e.g. alias closure as async-func), or in docs that explain why it doesn't work. | |
Ladislav 22-Mar-2013 [1812] | The question for me is why function doesn't work - actually, function in R3 works better than in R2! However, that still is far behind closure. |
Endo 22-Mar-2013 [1813] | Ladislav: "** Script error: a word is not bound to a context. -That is actually better than what you get in R2" Why is that? |
Ladislav 22-Mar-2013 [1814x2] | This is what you get in R2: f: func [a [number!]] [func [b [number!]] [a + b]] g: f 1 h: f 2 >> g 1 == 3 , this is much worse than error! |
(1 + 1) surely isn't 3 | |
Maxim 22-Mar-2013 [1816x2] | I don't agree, because 'H is defined within context of 'G and uses 'H binding. its both consistent and logical... because Rebol binding is supposed to be static. in the above example, I'd say the construct itself does what it should, but the real question is should one usually do this... no. I understand its a trap, but its not a trap for which the language is responsible, the user is simply leveraging the language. |
you have two functions which share a parent context. | |
Ladislav 22-Mar-2013 [1818] | I do not need explanation, I can give it as well. The problem is not explanation, the problem is expectation. |
Maxim 22-Mar-2013 [1819] | ah... but expectation has nothing to do with implementation or logic. expectation is *SOLELY* related to prior knowledge. so this is not a question of what *it* should do but of what *you* expect it should do. :-) |
Ladislav 22-Mar-2013 [1820x3] | Wrong addressee. I do not expect anything at all as I proved. What Pekr, Cyphre or other users expect is "real" to me, though. |
Closure is my "child" in a sense. I wrote it because I found it is what people want to have. | |
(instead of "explanations") | |
Maxim 22-Mar-2013 [1823] | have you tested how much overhead it causes on evaluation? |
Ladislav 22-Mar-2013 [1824x3] | As I said, it depends on the implementation, which may need more optimizations... |
(I wrote only a mezzanine "template", and suggested some tricks, but Carl wrote the actual implementation using my hints) | |
Did you test it? | |
Maxim 22-Mar-2013 [1827] | cause in my tests, binding is the single most demanding (low-level) operation for the interpreter. I am not trying to debunk your efforts for closure, which *should* be used more, I am just curious as to the impact it causes in real life. |
Ladislav 22-Mar-2013 [1828x4] | OK, any test results? |
As I mentioned, I already gave Carl an advice how to speed up binding in R3 substantially when compared to R2 | |
...and I know he used my advice obtaining a noticeable improvement | |
OTOH, there is still one trick that can be used to speed up rebinding in closure case. | |
Maxim 22-Mar-2013 [1832] | testing of binding itself on class vs prototype based oop for Rebol was several orders of magnitude when dealing with large objects. both in speed and RAM. I admit my tests are more on the extreme side of things, with the object in question taking up 80kb of RAM for every new instance. but when grouping up the functions of the object into a "sub" object, like face/feel, instead of letting them live within the face itself, speedup was exponential. at 1000 objects it was probably about 10 times faster, at 10000 objects it was about 25 times faster and I couldn't even allocate 100000 prototype objects and it crashed after a full 76 minutes of crunching at 100% CPU. a 1'000'000 object test with "classes" took 4 minutes and 400MB... so you can see that binding is a very significant part of the processing of Rebol, when it is required often. obviously, some peeking into the C sources will allow us to optimize all of this, (especially if it can be memcopied directly) but by default, as in R2, closures would theoretically be quite a hit in performance. |
Ladislav 22-Mar-2013 [1833] | So, obviously, totally unrelated tests. |
Maxim 22-Mar-2013 [1834] | related, tests which show that run-time rebinding must be avoided at all costs. if closures are forced to rebind, there will be a hit. my question was initially to know if you had done tests with closure itself... cause I am curious how well it compares to the default case of doing it all on the interpreter side. |
Ladislav 22-Mar-2013 [1835] | I see no point in: - testing in R2 where the native implementation of closure does not exist - testing in R2 where the binding algorithm is substantially slower - using test R2 results for faces to infer about R3 implementation of closures |
Andreas 22-Mar-2013 [1836x4] | R3 A111 / Linux-x86: >> f: func [x y] [x + y] >> dt [loop 1'000'000 [f 10 20]] == 0:00:00.18006 >> q >> c: closure [x y] [x + y] >> dt [loop 1'000'000 [c 10 20]] == 0:00:00.882204 |
R3 master, current rebolsource.net build for Linux-x86: >> f: func [x y] [x + y] >> dt [loop 1'000'000 [f 10 20]] == 0:00:00.158908 >> c: closure [x y] [x + y] >> dt [loop 1'000'000 [c 10 20]] == 0:00:00.279227 | |
Well, stupid measurements, sorry. The A111 measurement is an outlier. Need to do more statistically sound measurements. | |
f: func [x y] [x + y] c: closure [x y] [x + y] loop 30 [ print [ dt [loop 1'000'000 [f 10 20]] dt [loop 1'000'000 [c 10 20]] ] ] R3 A111 Linux-x86: function: 0.16014277 avg closure: 0.29911023 avg 86.7% +/- 1.6% difference at 99.5% confidence (t-test) | |
AdrianS 22-Mar-2013 [1840] | It would be interesting to see how that difference varies as the complexity of the body increases. |
Ladislav 22-Mar-2013 [1841] | Here is an example with a complex body: f: func [n x y] [ loop n [ loop n [ loop n [ x + y ] ] ] ] c: closure [n x y] [ loop n [ loop n [ loop n [ x + y ] ] ] ] >> time-block [f 10 10 20] 0,05 == 0.00017675781250000002 >> time-block [c 10 10 20] 0,05 == 0.000158203125 |
AdrianS 22-Mar-2013 [1842] | the closure is more efficient? |
Ladislav 22-Mar-2013 [1843] | Yes |
Ladislav 23-Mar-2013 [1844] | See also http://issue.cc/r3/1946 to note that there is almost no limit how much more inefficient can R3 functions be compared to closures. This is unacceptable taking into account that R3 functions purportedly are a "compromise solution" sacrificing correctness, reliability, comfort for speed. |
GiuseppeC 23-Mar-2013 [1845] | Is the "Bindology" article still valid for R3 ? |
Ladislav 23-Mar-2013 [1846] | Well, changes exist. It is useful to read it even when trying to understand how it is supposed to work in R3. It would be better to update it for R3, though. |
SWhite 4-Apr-2013 [1847] | OK, now I know the answer and it is time to confess it. I have complained a number of times about how obscure REBOL is (to me) and how I sometimes can look at ONE LINE of code and not understand it. I wonder, is it REBOL, or is it me. Well, I am learning python for work, and I want to replce the html lt and gt symbols with their character entities or whatever they are called, I found a sample on the internet, wrote up a test program, copied the sample, and it worked. So here I am looking at ONE LINE of python code and I don't understand how it works. So, the answer to, is it REBOL or is it me, is, IT'S ME. I think I'm in the wrong line of work. |
Gregg 4-Apr-2013 [1848] | It all depends on the line of code Steven. :-) Still, if there's something you enjoy more, that makes you feel like it clicks in your head, do that. |
Arnold 4-Apr-2013 [1849x3] | In most languages it is possible to do things in one line. Very often the result is that it is hard to understand what happens in that line. In the light of maintainable code I have the attitude that I rather deal with less comlicated code that is possibly a little slower. If that is not an option (most of the time performance stays way within limits even if it is readable) then I leave a big comment what the code is about. For sure the next guy/girl will appreciate this when it is their turn. There have been many occasions that I myself was the assigned the next adaptations and only a few months later these comments really were helpful. |
Some guys are wizzards, but they do not take into account the maintainability of their code by others. Real wizzards make good clear readable code. | |
And leaving complicated code without comments because you understand it (at the moment of creating the code) is also bad practice. As a professional coder I comment a lot, maybe because sometimes it is not appealing to come back later for more headaches from bad coding practice from colleagues ;) | |
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