World: r3wp
[XML] xml related conversations
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BrianH 23-Jun-2009 [650x2] | XML *is* case-sensitive. Your paths can't access multiple subelements of the same type, or embedded text. |
I wrote a simple xpath compiler too (but don't know where it is now). | |
Maxim 23-Jun-2009 [652] | I wanted direct access to all elements within rebol. |
Graham 23-Jun-2009 [653] | Looks like we need an article on best practices here ... |
Maxim 23-Jun-2009 [654] | a later version, using schema validation, understands multiple subelements and automatically converts them to blocks IIRC. so you do document/element/3/subelement/#attribute. |
BrianH 23-Jun-2009 [655] | Your paths can't access multiple subelements of the same type, or embedded text. It might have worked for that customer but not the general case. No namespace support either. |
Maxim 23-Jun-2009 [656] | my paths.. namespace works... for sure. did you know you can have colon in word names in R2 ! but i didn;t use that, I just used tags directly. more obvious than strings, and the exact same effort and speed. |
BrianH 23-Jun-2009 [657] | I was parsing xhtml and other XML of the like. Subelements of mixed types in order with text between them than mattered. |
Maxim 23-Jun-2009 [658x3] | my engine does support embedded types, but ignored it by default... it was also byte reversible... a loaded xml block loaded through the engine was saved back exactly, byte for byte, checksum proofed. |
oops.. embedded text I mean. | |
but all of that is not open source. | |
BrianH 23-Jun-2009 [661] | And mine is lost :( |
Maxim 23-Jun-2009 [662x2] | my newer version doesn't have the schema validation process.... that is a very complex engine to build. schemas and Parse traversal do not follow the same algorythm... so its a bitch to implement. |
anyhow... the xml tools I currently have are not yet tested enough to be release ready. | |
Graham 23-Jun-2009 [664] | Ok, so we have established that everyone does it their own way :) |
Maxim 23-Jun-2009 [665] | but the rebxml tools (on rebol.org) as-is are very usefull, so some utf-8 support and are less buggy than rebelXML in my previous tests. |
Graham 23-Jun-2009 [666x4] | rebelxml gets confused if there is more than one path with the same name |
it accepts the first one it finds | |
even if the full path is specified. | |
I suspect the author is no longer reboling | |
Maxim 23-Jun-2009 [670] | I remeber it also tripping on some of the XML files I gave it... don't remember the problems... but its error handling /recovery was very shaky IIRC. |
Graham 23-Jun-2009 [671x2] | You should add a comment to the discussion page if you remember. |
as should i. | |
Maxim 23-Jun-2009 [673] | read above, I don't ;-) |
Graham 23-Jun-2009 [674x3] | at this time .. it may come back to you |
that's why I said "if" ... | |
Using objects means i can store the functions that initialize it inside the object. | |
BrianH 23-Jun-2009 [677] | Not a good idea for data objects, which could number in the thousands, each with their own bound copy of the functions. |
Maxim 23-Jun-2009 [678] | yes, the best method is to have some form of dtd or schema, and use class-based objects. |
BrianH 23-Jun-2009 [679] | Class-based objects are emulated in REBOL. |
Maxim 23-Jun-2009 [680x2] | the init is a context with one function, to which you supply the outer (instance) which holds the data: my-tag: context [ data: "tototo" attribute-1: "red" class: context [ init: func [instance][ instance/data: copy "" instance/attribute-1: copy "blue" ] ] ] to init the an instance of my-tag: new-tag: make my-tag [class/init self] |
class is shared amongst all my-tag instances, and is never bound to any of them, so its both very fast and very RAM efficient.. exponentially so with large classes. | |
Graham 24-Jun-2009 [682x2] | That's what i was going to do initially, but I thought it would be easier to maintain if I kept the init methods inside the objects |
Perhaps I'm not clear on this .... If I create a pharmacy object like this pharmacy: make object! [ name: none init: func [ n ][ self/name: n ] ] is the init function shared by all the subsequent pharmacy instances? | |
Maxim 24-Jun-2009 [684] | it is bound each time, so if you have 2000 instances, you actually have 2000 times that function in ram, it adds up quickly for larger objects... for such a simple object, it might not be all that bad... |
Graham 24-Jun-2009 [685] | what's the diff between yours and mine? |
Maxim 24-Jun-2009 [686x2] | my example above, will share the init function amongst all the 2000 objects... and its going to be faster since no binding occurs... well only the CLASS word is bound but its content is the same in all instances. |
with liquid the difference is staggering when over 10000 objects. | |
Graham 24-Jun-2009 [688x2] | well, I doubt that I would have more than a few hundred objects... but ... |
unclear as to why yours is shared and mine isn't | |
Maxim 24-Jun-2009 [690x2] | but its a large object. still using the class system, I can allocate 1000000 nodes using about 400MB. with instances, 10000 obects take much more than that. |
R2 shares objects within objects. the class is not re-created at each make []. | |
Graham 24-Jun-2009 [692x2] | Oh .... |
is it objects within objects within objects? | |
BrianH 24-Jun-2009 [694] | But then the class functions are accessed through obj/class/method obj, insstead of obj/method. |
Graham 24-Jun-2009 [695] | so if I have pharmacy: make object! [ address: make addressobj [ ] ] and the address object has objects in it ... they will be shared?? |
BrianH 24-Jun-2009 [696] | Yeah. |
Graham 24-Jun-2009 [697x3] | Ouch |
So, how does one create nested unique objects? | |
Create them using the init function ?? | |
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