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Thread: xmlHashScanner type ought to return a bool...
xmlHashScanner type ought to return a bool...
user name
 2007-01-25 14:52:10 

  


  

    I'd like to suggest that the various xmlHashScan functions be modified so
that the function pointer passed to them can return a bool indicating
whether the scan should continue or not.

I have a case where I have to basically reverse a hash scan - given
something about the data hashed, locate a string that maps to that data.

So what I might have is:

struct something

{
   int a;
   int b;
};

and a hash mapping a bunch of strings to different instances of something.
Now, I want to find a string which maps to a "something" with a .a value
of 12.

Now, unless I have some other entity besides the hash which lists all the
possible somethings, the only way to find a "something" with .a=12 would
be to create a hash scanner function that checks each item in the hash and
records the first item which has .a=12 - but then I am going to iterate
over the whole rest of the hash after having found my object.


If the hash scanner function could return TRUE = (continue scanning) or
FALSE = (stop scanning), then I could stop the search when I've found the
data.

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    Re:  xmlHashScanner	type ought to return
a bool...
  


  

     user name

     2007-01-26 08:18:37
  


  

    

  


  

    On Thu, Jan 25, 2007 at 02:52:10PM -0600, David Hagood wrote:
> I'd like to suggest that the various xmlHashScan functions be modified so
> that the function pointer passed to them can return a bool indicating
> whether the scan should continue or not.
> 
> I have a case where I have to basically reverse a hash scan - given
> something about the data hashed, locate a string that maps to that data.
> 
> So what I might have is:
> 
> struct something

> {
>    int a;
>    int b;
> };
> 
> and a hash mapping a bunch of strings to different instances of something.
> Now, I want to find a string which maps to a "something" with a .a value
> of 12.
> 
> Now, unless I have some other entity besides the hash which lists all the
> possible somethings, the only way to find a "something" with .a=12 would
> be to create a hash scanner function that checks each item in the hash and
> records the first item which has .a=12 - but then I am going to iterate
> over the whole rest of the hash after having found my object.
> 
> If the hash scanner function could return TRUE = (continue scanning) or
> FALSE = (stop scanning), then I could stop the search when I've found the
> data.

  That would be a good idea, except it break both API compatibility and
ABI compatibility with previous versions, so that's just impossible. And
I'm not sure it's worth adding a new API at this point. 

Daniel

-- 
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