World: r3wp
[Core] Discuss core issues
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Steeve 23-Jul-2011 [1869x2] | you can redefine the word FORM as you wish, no ? |
Performances of rebol in general cases are the real subject here, I guess | |
Henrik 23-Jul-2011 [1871] | Steeve, btw, R3: >> form .00000000000000000000000000000000000000000000002 == "2.0e-47" |
Steeve 23-Jul-2011 [1872x2] | That's good |
The point is the lack of user types in rebol and also the lack of performances (GIT compilation needed) | |
Geomol 23-Jul-2011 [1874x5] | I maybe understand the reason to have things like #[none], #[true] and #[false] to specify those values, if someone choose to redefine none, true and false. I say "maybe", because I would be ok to let people to on their own, if they did such thing. But why have all the other #[] constructs? Is this making things simple or unnecessarily complex? |
*to let people on their own* | |
Or did I mean "to let people be on their own"? :) Probably. | |
When I see tickets like #941, I think "gees, so much energy wasted on such rubbish". Maybe I don't see the light, and then I'm sorry. | |
*geeze* (It's late here.) ;) | |
Oldes 23-Jul-2011 [1879x3] | true: not (false: true) |
btw... why we need the parens to get the expected result? >> mold/all true: not (false: true) == "#[true]" >> mold/all (true: not (false: true)) == "#[false]" | |
the above is in R3... in R2 it seems to be as I would expect: >> mold/all true: not (false: true) == "#[false]" | |
Ladislav 24-Jul-2011 [1882x5] | I maybe understand the reason to have things like #[none], #[true] and #[false] to specify those values, if someone choose to redefine none, true and false. - as far as I am concerned, you are missing the point, Geomol. My thoughts: 1) there is a Data exchange dialect in REBOL, which is the main REBOL dialect (considering the fact, other REBOL dialects are derived from it). A sidenote: the "Data exchange dialect" name may not be ideal. (this name is used in the http://en.wikipedia.org/wiki/REBOLarticle). Maybe, following the same "naming procedure" as for other dialects we could name it the "Load dialect"? 2) In the Data exchange dialect (or Load dialect, whichever you prefer), the none expression is a word, and you do not have any means how to express the #[none] value, except for this specially escaped format, the same holds for #[true], #[false], #[unset!], etc. |
Considering the fact, that any REBOL code is loaded first (in the computer, but your brain should follow a similar procedure when reading it), i.e. handled as the "Data exchange dialect"/"Load dialect" (pick the one you prefer) before being (eventually, but not necessarily) submitted to any other interpreting function (like DO, etc.), the specially escaped format is useful, since it increases the expressivity of the "Data exchange dialect"/"Load dialect" (pick your preferred one). | |
Oldes, regarding your example. It looks, that you messed up something. | |
I do not need any parens to write: >> true: #[true] false: #[false] mold/all true: not false: true == "#[false]" | |
BTW, at the Davis RebCon, Gregg asked which REBOL dialect is the one used most frequently, and he suggested the function specification dialect, IIRC. But, as you may have noticed, my favourite is the "Data exchange dialect"/the "Load dialect" (still did not pick the name you prefer?) | |
PeterWood 24-Jul-2011 [1887] | I think that Ladislav's point of view can be simply exemplified: >> type? first [none] == word! >> type? first [#[none] ] == none! and perhaps made clearer with an example using #[unset!]: >> type? unset! == datatype! >> type? first [unset! ] == word! >> type? first [#[unset!]] == unset! |
Ladislav 24-Jul-2011 [1888x2] | Any, if we define a DISPLAY-RESULT function as follows (in R3): display-result: func [value [any-type!]] [print ["==" mold/all :value newline]] , we obtain: >> display-result unset! == #[datatype! unset!] >> display-result quote unset! == unset! >> display-result quote #[unset!] == #[unset!] |
, which is (IMO) less confusing than >> unset! == unset! >> quote unset! == unset! >> quote #[unset!] >> | |
Geomol 24-Jul-2011 [1890] | The data exchange dialect is a good point to have constructs. Then my logic goes: REBOL values can be divided in two groups, 1. the ones with a non-ambigious lexical representation and 2. the ones without such lexical representation. Datatypes of values in the second group include: unset! none! logic! bitset! image! map! datatype! typeset! native! action! routine! op! function! object! library! error! port! event! and maybe a few more depending on what version of REBOL. The rest is in the first group. It would make sense to have constructs for the values in the 2nd group. Then I look at some examples of constructs: #[string! "abc"] #[email! "[abc-:-d]"] Those are not necessary. If it's because all values can be represented as constructs, then why doesn't this work? >> #[integer! 1] ** Syntax Error: Invalid construct -- #[ And how would values of type native!, action!, op!, etc. be represented as constructs? I'm not convinced. |
Izkata 24-Jul-2011 [1891] | Example of necessity for string! and other series! types: >> X: #[string! {abc} 2] == "bc" >> head X == "abc" |
Geomol 24-Jul-2011 [1892] | Ah, now I got it. Thanks! Is it complete, so natives, operators and functions can be made as constructs too? |
Ladislav 25-Jul-2011 [1893x3] | REBOL values can be divided in two groups, 1. the ones with a non-ambigious lexical representation and 2. the ones without such lexical representation. - Well, this is rather confusing for me, since e.g. #[none] is (for me) a "non-ambiguous lexical representation" of the value. But, your classification would be OK with me, if we just added a note like ("when the specially escaped representations are disregarded"). |
The Data exchange dialect (or the Load dialect) is incoplete in the following sense: - natives etc. do have specially escaped representations (MOLD/ALL creates them), but such representations are not loadable - MOLD/ALL creates loadable representations of REBOL objects and functions, but they are not guaranteed to preserve the properties of the orignal values | |
The "incomplete" above means "incomplete when compared with the DO dialect". | |
Geomol 25-Jul-2011 [1896x4] | natives etc. do have specially escaped representations (MOLD/ALL creates them) >> native? :until == true >> mold/all [until [true]] == "[until [true]]" How do I see the escaped representation? |
>> mold/all :until == "native" Hm, how is this useful? | |
Why not do this instead of having constructs? >> make logic! 0 == false >> make logic! 1 == true >> make none! 0 == none ... etc. | |
Sorry I answer myself, but it's probably because it gives a different kind of value when loaded: >> load {make logic! 0} == [make logic! 0 ] >> load {#[false]} == false | |
Ladislav 25-Jul-2011 [1900x6] | How do I see the escaped representation? - interesting, you seem quite seriously confused |
the [until [true]] block contains only words | |
>> mold/all :until == {#[native! [[ "Evaluates a block until it is TRUE. " block [block!] ]]]} | |
It is from R3, but, as said above, it is not loadable | |
Why not do this instead of having constructs? >> make logic! 0 == false , because it is confusing. I prefer this: >> display-result make logic! 0 == #[false] | |
(see the DISPLAY-RESULT function above) | |
Geomol 25-Jul-2011 [1906] | I guess, much of my confusion here comes from the fact, that I never had the need for constructs. If we follow the thought, that the none value should be shown as #[none] in the console, when it's a result, then the following should be shown as well: >> next "abc" == #[string! "abc" 2] I think, most people wouldn't want that. It's not very readable. I still ask myself, if all those constructs are really necessary taking the amount of work and time used into account. |
Henrik 25-Jul-2011 [1907] | I see them as necessary, otherwise you would not be able to serialize (or specially escape) any rebol code or data properly using a fixed method. This is very important for dialects. |
Geomol 25-Jul-2011 [1908] | Henrik, can you give a simple example, where the serialized format is needed? |
Henrik 25-Jul-2011 [1909] | every time I save REBOL data to disk? I use this hundreds of times every day. |
Geomol 25-Jul-2011 [1910] | What's wrong with using a simple SAVE? |
Henrik 25-Jul-2011 [1911] | you will lose every datatype that will be seen as words. |
Geomol 25-Jul-2011 [1912] | Not, if you LOAD the data back into a context, where those words have meaning. |
Henrik 25-Jul-2011 [1913x2] | no, some types may be *confused* as words. that's different. |
Basic example: >> save %file.txt none >> load %file.txt == none ; is it none? >> type? load %file.txt == word! ; nope >> save/all %file.txt none >> type? load %file.txt == none! ; yes, only with proper serialization | |
Geomol 25-Jul-2011 [1915x2] | It's kinda interesting, how complexity sneak into a language like REBOL. I have never used constructs. I save REBOL data and code to disk all the time. I even created a file system/database, that is all about saving and loading data and code. I get along using a combination of simple REBOL functions like SAVE, LOAD, REDUCE and DO. |
I understand, it can be argued, it's more simple to just use save/all .... load ... than something like save ... do load ... or maybe ... reduce load ... but trying to make this simple result in a much more complex language. (as I see it) | |
Henrik 25-Jul-2011 [1917] | I'm not sure that's a complexity. It's a basic need, when transfering REBOL data somewhere else, using strings or binaries. There is simply a loss of information, if the data is transferred in an unserialized fashion. |
Geomol 25-Jul-2011 [1918] | As code is also data in REBOL, and because natives can't be loaded and there are bugs like in making function constructs, then I see this as half-hearted. It kinda work, but not really. |
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