World: r3wp
[!REBOL3-OLD1]
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Maxim 3-Jun-2009 [15078] | but I would like a way to get invalid tokens loaded as invalid values... that way I'd use block parsing . so far, I've been using string parsing about 90% of the time. its a shame, since I'm loading stuff much more slowly than rebol could let me do it using its native loading. |
Steeve 3-Jun-2009 [15079] | but behaving like regular variables |
Maxim 3-Jun-2009 [15080x2] | we are talking about representing the lexical form of unit-like values here steeve, not the custom datatypes. |
all OOP with accessors do exactly what you want. | |
Steeve 3-Jun-2009 [15082x2] | i'ts the same thing, you just need a specific method (ie. dispalyed-as) for the computed vars |
yes i can do it with OOP, but i don't want to have to code stupid things like my-var/set, my-var/get | |
BrianH 3-Jun-2009 [15084] | But Carl don't like the idea - as I recall, changes in object semantics have been put off until later, not permanently. |
Maxim 3-Jun-2009 [15085x3] | those variables would be sort of objects with methods that is exactly WHAT an accessor-enabled variable IS , also known as a datatype ;-) |
the accessors are just events... you have to know WHEN and WHAT to do with a variable... It would be fun if generic objects allowed us to set accessors per instance, just like python allows it, but alas, Carl doesn't realise just how often this could be used to simply a vast array of code. | |
simply = simplify | |
BrianH 3-Jun-2009 [15088] | (repeating myself) As I recall, changes in object semantics have been put off until later, not permanently. |
Steeve 3-Jun-2009 [15089] | i don't ask a new semantic for objects (with obvious drawbacks) i ask for a new datatype, let the objects like they are |
BrianH 3-Jun-2009 [15090] | All bound words are object fields or function context fields, so that is exactly what you are asking for. |
Steeve 3-Jun-2009 [15091] | yep so do it now :-) |
BrianH 3-Jun-2009 [15092] | put off until later, not permanently |
Sunanda 3-Jun-2009 [15093] | Petr < has anyone problem, if money! datatype would be renamed to unit!> Agreed ---- It seems likely that if money! had not existed in R2, none of us would be expecting R3's BCD datatye to be called money! Given that so much of R3 is a break from R2, Let's make the small change [deliberate currency pun] and give it a better name. We could keep money as a subtype of that. |
BrianH 3-Jun-2009 [15094] | Since objects are the basis of all datatypes where words can be bound, we are focusing on the design of those other datatypes first so we get a better idea of the requirements for objects. Other datatypes like modules and tasks, for example. |
Steeve 3-Jun-2009 [15095] | as-is! (which mean nothing or all) |
BrianH 3-Jun-2009 [15096] | ? |
Steeve 3-Jun-2009 [15097x2] | I was answering to Sunanda, a new name to replace money! |
exact! | |
BrianH 3-Jun-2009 [15099x4] | Maxim's suggestion might work syntactically, but we would lose the money! syntax, which is the ISO standard syntax for currency. If we added a unit! type with Maxim's syntax we could use the same implementation internally for both money! and unit!. |
They would just differ in syntax. | |
However, remember that there are limits to the number of possible distinct units loaded at once. The value doesn't have more than 1 byte available to refer to a unit, which means 255 possible units in use when you subtract the unspecified unit. | |
Carl had a blog about this related to money! ... | |
Steeve 3-Jun-2009 [15103] | well, in some time, the dollar wil disappear, so we'll got one more unit free |
BrianH 3-Jun-2009 [15104x2] | I'm just using money! and unit! as placeholder names for the two datatypes though. Final names should be decided. The money! name is a good one for the current money! syntax because the syntax matches the international currency syntax standard. |
The $ is part of the ISO standard, as is the limit of 3 alphabetic characters preceeding it. | |
Maxim 3-Jun-2009 [15106] | quoting brian " the syntax matches the international currency syntax standard" well... to me that's resoved then .... lets call it currency! :-) |
BrianH 3-Jun-2009 [15107] | money! means the same thing and is shorter :) |
Maxim 3-Jun-2009 [15108x2] | I've just looked up the terms in the dictionnary ... and money actually encompasses currency, so it actually is the more precise term here... funny, I had the two words inversed in my head. |
funny no one noticed the big lexical change proposed in my example unit-conversion example ... or no one spotted it ;-) | |
BrianH 3-Jun-2009 [15110] | I just translated the function to a more efficient method in my head. What is the lexical change you mention, aside from the unit syntax? |
Maxim 3-Jun-2009 [15111x2] | I meant to say: "no one argued about the .... " |
note how inches are represented lexically... ;-) | |
BrianH 3-Jun-2009 [15113] | Oh, the unit syntax. There would be limits to what you could do, but the principle is sound. You probably wouldn't be able to do 1". |
Maxim 3-Jun-2009 [15114] | hehe actually we could, but I understand that it woul make the lexical analyser that much more complex than it is already with the "" vs {} handling inside/outside of each other... adding the " to word would really make it complex. so I don't expect or specifically "want" it, just was wondering if some of you would react to it ;-) |
BrianH 3-Jun-2009 [15115] | The lexical analyzer has syntax priorities - some characters are delimiters, " being one of those. |
Maarten 3-Jun-2009 [15116x2] | You need first-class functions to have continuations. |
But, if you want them to have reasonable speed... some native support helps... | |
BrianH 3-Jun-2009 [15118x2] | If you want continuations supported well you need to build on a continuation-passing-style runtime. As far as I know, the only practical one with good performance is Parrot. |
That is, unless you switch to a compiled language. | |
Janko 3-Jun-2009 [15120] | brian, you seem to really know what's happening at various languages scene.. cool .. I was just looking a talk (video) about parrot VM where it presented these things few weeks back where a woman was presenting these features (and I consider myself a language nutcase ;) ) |
BrianH 3-Jun-2009 [15121x3] | I haven't really followed Parrot for a couple years - lost interest. Suppose I should take another look. |
I'm not sure what model Stackless Python uses - in theory if could use CPS, but I haven't checked yet. | |
Strangely enough, the intermediate codes of many compiled dynamic languages are switching to SSE, which is procedural CPS. | |
Janko 3-Jun-2009 [15124] | CPS is cont. passing system... what is SSE ? :) |
BrianH 3-Jun-2009 [15125x2] | Static Single Assignment. |
CPS = Continuation-Passing Style. | |
Janko 3-Jun-2009 [15127] | aha.. like in functional languages? |
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