mathlib-develop

[Mathlib-develop] Change to MathLibObject/VariableList implementation

[mark <msp...@ya...>]

Hi,

Both the MathLibObject and the VariableList classes implement lists of na=
med=20
variables. They are both implemented using ArrayLists.

This is ineficient since when finding a variable by name it is necessary =
to=20
iterate through the list until we find the correct variable.

I think that it would be better to implement these classes using a HashMa=
p=20
since it would speed up variable access and is a better fit to the proble=
m.

The only downside I can see is that the code needed to iterate through a=20
hashes key/value pairs is, to put it politely, suboptimal.

What I will most likely do is work on this in a local copy of the code an=
d=20
only commit it if there aren't any problems.

Any comments?
=20
Best Regards

Mark Sparshatt

Re: [Mathlib-develop] Change to MathLibObject/VariableList implementation

[Stefan M. <st...@he...>]

HI Mark,
I aggree. Please go ahead.
Stefan.

mark wrote:
> Hi,
> 
> Both the MathLibObject and the VariableList classes implement lists of named 
> variables. They are both implemented using ArrayLists.
> 
> This is ineficient since when finding a variable by name it is necessary to 
> iterate through the list until we find the correct variable.
> 
> I think that it would be better to implement these classes using a HashMap 
> since it would speed up variable access and is a better fit to the problem.
> 
> The only downside I can see is that the code needed to iterate through a 
> hashes key/value pairs is, to put it politely, suboptimal.
> 
> What I will most likely do is work on this in a local copy of the code and 
> only commit it if there aren't any problems.
> 
> Any comments?
>  
> Best Regards
> 
> Mark Sparshatt
> 
> 
> 
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-- 
------------------------------------
Dr.-Ing. Stefan Mueller
email: St...@he...
------------------------------------

Re: [Mathlib-develop] Change to MathLibObject/VariableList implementation

[mark <msp...@ya...>]

On Wednesday 23 Jul 2003 7:46 pm, Stefan Mueller wrote:
> HI Mark,
> I aggree. Please go ahead.
> Stefan.
>
> mark wrote:
> > Hi,
> >
> > Both the MathLibObject and the VariableList classes implement lists o=
f
> > named variables. They are both implemented using ArrayLists.
> >
> > This is ineficient since when finding a variable by name it is necess=
ary
> > to iterate through the list until we find the correct variable.
> >
> > I think that it would be better to implement these classes using a
> > HashMap since it would speed up variable access and is a better fit t=
o
> > the problem.
> >
> > The only downside I can see is that the code needed to iterate throug=
h a
> > hashes key/value pairs is, to put it politely, suboptimal.
> >
> > What I will most likely do is work on this in a local copy of the cod=
e
> > and only commit it if there aren't any problems.
> >
> > Any comments?
> >

Okay I've changed the MathLibObject and VariableList to use a hash and=20
committed them. You'll probably need to do an ant clean  before rebuildin=
g.

Best regards

Mark Sparshatt
=20