World: r3wp
[Core] Discuss core issues
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Maxim 12-Feb-2007 [7161x2] | It would be nice in R3 if we could remove things from an object when deriving with make... (we can , sort of, using the 'THIRD accessor on an object and editing it....) |
but when the object is being created by another controler (like in view) then we can't really... | |
PeterWood 12-Feb-2007 [7163] | So you'd really like Rebol to have the equivalent of JavaScript's Delete operator? |
Maxim 12-Feb-2007 [7164x2] | hum don't know about it... but if I could do obj: make/without ref-obj [] [select] We could already shrink our objects, when its needed. |
binding would then have to replace any object-local bindings of select to the global context and raise an error if it doesn't exist, as it would if you had tried to define a new object with select undefined in any place. | |
PeterWood 12-Feb-2007 [7166x2] | One think that I like in JavaScript is the flexibility to freely add and remove members from object instances and object prototypes . |
think -> thing | |
Maxim 12-Feb-2007 [7168x2] | it is usefull only when it is something which is not automatic like in python, where its nightmarish. |
if you inadvertently typo , then you create a new member! talk about hard to debug errors!! | |
Joe 13-Feb-2007 [7170] | how does the path native work ? I couldn't find it in the rebol dictionary |
BrianH 13-Feb-2007 [7171] | Joe, that native is an accidently exposed internal function. It has no use externally. |
Henrik 14-Feb-2007 [7172] | If I'm calling a function with many different refinements and the function has to work recursively and all refinements must be maintained throughout recursion, is there an easy way to get the function call with all refinements? I'm using: >> f: func [/a /b] [to-path remove-each p reduce ['f all [a 'a] all [b 'b]] [none? p]] >> f == f >> f/a == f/a >> f/b/a == f/a/b ; lose refinement order |
Anton 14-Feb-2007 [7173x4] | I'm not sure if this helps but I sometimes make a wrapper function which calls the actual recursive function. The wrapper could take the refinements and set some flags in a context shared by all calls to the inner recursion function. |
Oh hang on, your question indicates that your example code above is currently working, but you are looking for a better way. Is that correct ? | |
A "how was this function called ?" function. I don't think there is a way. (although in recent discussion on BIND?....) | |
ooh.. actually.... | |
Henrik 14-Feb-2007 [7177] | 1. it currently works but is clumsy, I think 2. "how was this function called ?" = yes |
Anton 14-Feb-2007 [7178] | How about this: >> f: func [/a /b][print mold second bind? 'a] >> f/a/b [true true] :) |
Henrik 14-Feb-2007 [7179x2] | there is something about that you don't know the actual function name inside the function? if only the refinements and their order could be managed. |
testing... | |
Anton 14-Feb-2007 [7181x2] | That's right, since several words can refer to the same function, it has no "one" word. |
(it also could be an anonymous function) | |
Henrik 14-Feb-2007 [7183] | well, that only brings up a block and the refinement order is still off, which would be a problem if your refinements have arguments |
Anton 14-Feb-2007 [7184x2] | I see. |
I think you must pass in the code which is used to launch the function as a function argument :) | |
Henrik 14-Feb-2007 [7186] | nasty! |
Anton 14-Feb-2007 [7187] | yep :) |
Henrik 14-Feb-2007 [7188x2] | I wonder how hard this would be to implement in a single function. Probably very hard if functions internally are unaware of refinement order |
very hard = impossible :-) | |
Anton 14-Feb-2007 [7190x3] | Well, given a function f: func [code /a /b][print mold second bind? 'a] do append/only copy code: [f/b] code ---> [[f/b] none true] |
Since I've passed in the code to call the function, it knows how it was called, and the order of refinements. The refinements are listed in spec order in the function context though. | |
What's the actual application for this recursive function, by the way ? | |
Henrik 14-Feb-2007 [7193] | it's a file packing function. refinements are used to determine which files should be skipped and which files should be processed with other external functions |
Anton 14-Feb-2007 [7194] | And why does it need to be recursive ? Recursing directories ? |
Henrik 14-Feb-2007 [7195x2] | I use it in many places for slightly different purposes |
yes | |
Anton 14-Feb-2007 [7197] | ok, so more an abstract general idea. |
Ladislav 14-Feb-2007 [7198x2] | I think you must pass in the code which is used to launch the function as a function argument :) no need, pass-args can handle everything |
, but a native APPLY handling refinements transparently would definitely help | |
Gabriele 14-Feb-2007 [7200x4] | Henrik: why is the refinement order important to you? (since there's no way to know it from inside a function) |
if you have control over the function, write a (recursive) function without refinements and a wrapper with refinements that calls it. (this is the best solution) | |
if you don't have control over the function, Ladislav's pass-args or similar techniques are the most general way to solve the problem. easier/faster solutions may be available in specific cases. | |
a native APPLY would solve all of this elegantly... hopefully we'll get one :) | |
CharlesS 15-Feb-2007 [7204] | aye, I look forward to apply too :) |
Robert 19-Feb-2007 [7205] | What does PATH do? |
Rebolek 19-Feb-2007 [7206] | in immortal words of Kurt Cobain "who knows? not me." and this probably won't help very much: >> ?? a a: make object! [ b: 1 ] >> path a 'b >> ?? a a: make object! [ b: end ] |
Oldes 19-Feb-2007 [7207] | this is thee end...this is thee end my friend... (but that's another song..) |
PeterWood 19-Feb-2007 [7208] | So what does end do? |
Rebolek 19-Feb-2007 [7209x2] | I don't know. let's continue with the example: >> type? a/b == unset! |
well, that's my fault, sorry | |
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