www.digitalmars.com         C & C++   DMDScript  

digitalmars.D - Compile time XML Parser?

reply Kaitlyn Emmons <katemmons0 gmail.com> writes:
Is there one in existence?

-Kaitlyn
Feb 04 2020
next sibling parent reply Adam D. Ruppe <destructionator gmail.com> writes:
On Wednesday, 5 February 2020 at 01:43:24 UTC, Kaitlyn Emmons 
wrote:

 Is there one in existence?


Most ordinary xml D parser can run at compile time.

I've tested my dom.d with it and it parses successfully, though 
several actual manipulations cause the compiler to crash [!].

import arsd.dom;

string translate(string xml) {
         auto document = new Document(xml, true, true);
         foreach(p; document.querySelectorAll("p"))
                 p.removeAllChildren(); // this worked at least
                 //p.innerText = "compile time"; // crashed!
                 //p.addClass("paragraph"); // crashed!
         return document.toString();
}

// with the `enum` keyword, it runs the function at compile-time
enum e = translate("<xml><p>cool</p></xml>");

void main() {
         pragma(msg, e); // and this prints the result as it 
compiles
}
Feb 04 2020
parent reply Kaitlyn Emmons <katemmons0 gmail.com> writes:
On Wednesday, 5 February 2020 at 01:51:07 UTC, Adam D. Ruppe 
wrote:

 On Wednesday, 5 February 2020 at 01:43:24 UTC, Kaitlyn Emmons 
 wrote:

 Is there one in existence?


 Most ordinary xml D parser can run at compile time.

 I've tested my dom.d with it and it parses successfully, though 
 several actual manipulations cause the compiler to crash [!].

 import arsd.dom;

 string translate(string xml) {
         auto document = new Document(xml, true, true);
         foreach(p; document.querySelectorAll("p"))
                 p.removeAllChildren(); // this worked at least
                 //p.innerText = "compile time"; // crashed!
                 //p.addClass("paragraph"); // crashed!
         return document.toString();
 }

 // with the `enum` keyword, it runs the function at compile-time
 enum e = translate("<xml><p>cool</p></xml>");

 void main() {
         pragma(msg, e); // and this prints the result as it 
 compiles
 }


It crash from manipulation but does it ever crash just parse and 
read? I dont need manipulation, just parse and read. Going to try 
parse and auto generate a VK binding from VKapi.xml that krhonos 
releases :) But it is big and complex xml so need stable parser.
Feb 04 2020
parent reply Adam D. Ruppe <destructionator gmail.com> writes:
On Wednesday, 5 February 2020 at 02:06:58 UTC, Kaitlyn Emmons 
wrote:

 It crash from manipulation but does it ever crash just parse 
 and read?


Not for me but I almost always just do it at runtime; the compile 
time isn't as well tested. (I've only done little things with it 
at CT)

But the same principle should apply to the other D xml parsers so 
maybe one of them will be better.


 to try parse and auto generate a VK binding from VKapi.xml that 
 krhonos releases :) But it is big and complex xml so need 
 stable parser.


You might be better off doing it at run time anyway - write a 
program to load the xml and generate it as a separate step in 
your build process.

With a CT binding, every single build is going to have to reparse 
all the xml and regenerate the binding and the compile time 
function executor in the compiler is kinda slow.
Feb 04 2020
parent reply Kaitlyn Emmons <katemmons0 gmail.com> writes:
On Wednesday, 5 February 2020 at 02:20:00 UTC, Adam D. Ruppe 
wrote:

 On Wednesday, 5 February 2020 at 02:06:58 UTC, Kaitlyn Emmons 
 wrote:

 It crash from manipulation but does it ever crash just parse 
 and read?


 Not for me but I almost always just do it at runtime; the 
 compile time isn't as well tested. (I've only done little 
 things with it at CT)

 But the same principle should apply to the other D xml parsers 
 so maybe one of them will be better.


 to try parse and auto generate a VK binding from VKapi.xml 
 that krhonos releases :) But it is big and complex xml so need 
 stable parser.


 You might be better off doing it at run time anyway - write a 
 program to load the xml and generate it as a separate step in 
 your build process.

 With a CT binding, every single build is going to have to 
 reparse all the xml and regenerate the binding and the compile 
 time function executor in the compiler is kinda slow.


simple build process > fast build process .. not gana fuck with 
two step build system who got time for that... not me lol... also 
if it is separate module and does not import other modules, 
shouldn't rdmd recognize it doesnt need recompilation if the xml 
and module dont change?
Feb 04 2020
parent Adam D. Ruppe <destructionator gmail.com> writes:
On Wednesday, 5 February 2020 at 04:37:34 UTC, Kaitlyn Emmons 
wrote:

 simple build process > fast build process


hah yeah i know how you feel. Though I want BOTH!

The good news is almost all your code would actually be the same 
thanks to CTFE calling ordinary functions. So if you change your 
mind, you can change like `mixin(generate())` to 
`file.write(generate())` and otherwise basically keep it the same.

So an easy decision to change your mind on if needs be in the 
future.


 modules, shouldn't rdmd recognize it doesnt need recompilation 
 if the xml and module dont change?


rdmd only caches the end result, not intermediaries. But other 
builds can do it... just at the cost of some of that simplicity.
Feb 05 2020
prev sibling parent Jonathan M Davis <newsgroup.d jmdavisprog.com> writes:
On Tuesday, February 4, 2020 6:43:24 PM MST Kaitlyn Emmons via Digitalmars-d 
wrote:

 Is there one in existence?


I believe that dxml works at compile-time, since IIRC, after I gave my talk
on it, someone created a PR to make the few changes necessary to make it
work at compile-time:

http://code.dlang.org/packages/dxml

I haven't ever used it at compile-time myself though.

- Jonathan M Davis
Feb 04 2020