I just cannot understand how to solve XML related problems by using this
library.
Perhaps there is lack of examples, and no description of functions purpose.
And from bare description I am failing to imagine practical use.
For example, why (source) struct exists? And how I can use it?
Why there functions (read-xml/document [in]) and (read-xml/element [in])
And how i can use them?
As I mentioned earlier, my guess was that I can process XML sequentially by
using them in tandem, but it seems this guess was wrong.
What is the pattern for navigating inside (element) structure? For example
getting to ROOT->tagA->tagB ?
And I cannot go from tagB to tagA, rigth?
Lets assume such XML:
<ROOT>
<A>
<B1>test</B1>
<B2>"test qoute"</B2>
</A>
<A>
<B1>test2</B1>
<B2>"test "qoute2""</B2>
</A>
</ROOT>
I want to transform this into list of struct (data b1 b2)
And perhaps do this in sequential manner if i need to parse 10 millions of
A tags.
I tried to use (se-path*/list), like this:
(define rawmxl "<ROOT><A><B1>test</B1><B2>"test
qoute"</B2></A><A><B1>test2</B1><B2>"test
"qoute2""</B2></A></ROOT>")
(define xexpr (string->xexpr rawmxl))
(se-path*/list '(A) xexpr)
But this gives me plain list:
'((B1 () "test") (B2 () "\"" "test qoute" "\"") (B1 () "test2") (B2 () "\""
"test " "\"" "qoute2" "\"" "\""))
Without distinction of what A tag content is where.
So i cannot reason about it.
And (se-path*/list '(A B2) xexpr) gives me:
'("\"" "test qoute" "\"" "\"" "test " "\"" "qoute2" "\"" "\"")
so this is even worse.
And it will be great if a can get 1 list from the beginning, because I have
20 millions of this records.
So now I am moved to (match) solution.
For example:
(match xexpr
[(list 'ROOT '()
(list 'A '()
(list 'B1 '() b1)
(list 'B2 '() b2 __1)) __1) (list b1 b2)]
[_ 'empty])
Now I am getting somewhere, but I get 2 separate lists again, and I am not
sure about memory effectiveness of match (I am assume it is effective).
Can I get one list of structs in this scenario? (without manually looping
over A tags) and how about nested (match) effectiveness?
And now I begin to feel that parsing raw XML "by hand" won't be much harder
then solution I am getting now. Perhaps this is due to intrinsic nature of
XML itself?
пятница, 22 ноября 2019 г., 17:10:19 UTC+2 пользователь Sage Gerard написал:
>
> I'm interested in this quote:
>
> [...] creating a huge problems with even simple XML parsing. (I am
> basically battling XML lib all day already to do most simple tasks)
>
>
> I think that when you asked about why the xml collection behaves the way
> it does, the conversation turned away from your experience.
>
> Could you elaborate on the specifics of what you are trying to do in one
> of your projects so that we can see your pain points in context?
>
> *~slg*
>
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