New Construct

[Kermit Kiser]

George --

I did research converting class Rexx to use Hashmaps as we discussed earlier, but found that RexxNodes are required due to the way that values are assigned so there is no great advantage to using Hashmaps over Hashtables even though they accept null keys and values. Also, adding the "isIndexed" and "size" methods did not require a change, so CLDC should not be affected. I will keep in mind the requirement to have NetRexx runtime be small for use in limited devices and Android, etc.

-- Kermit


On 10/5/2011 7:56 AM, George Hovey wrote:

Hi Mike,
Re

"In general I tried to make the Rexx classes as standalone as possible, and split them in a way to try and minimise what would get pulled in."

and Kermit's inquiry about adding Rexx constructors.

I'm in the midst of an effort to port NetRexx to a device operating under Sun's Connected Limited Device Configuration (CLDC).  [http://shap.inf.tu-dresden.de/]  As you know, this is for severely memory-constrained devices and makes available only a handful of Java classes.

It has long been my dream to port NetRexx to a JVM operating in a Field Programmable Gate Array (FPGA), as this would have some important laboratory applications (and support the luxurious programming environment to which I've become accustomed!).  Before I saw the NetRexxR source I feared I would need to incorporate many Java classes which would in turn drag in more, until the whole thing ballooned out of control.

I was relieved to discover that NetRexxR uses Java very sparingly.  The collection classes needed -- Vector, Hashtable, etc -- are included in CLDC.  The I/O classes are not, but they have (pretty much) direct replacements in CLDC.  I still have some issues related to Ask but, I think, don't involve NetRexx.  The actual changes required are rather small (though the background reading was not 8-) ).

I hope our architects will keep in mind your "principle of parsimony" with respect to use of Java classes in the runtime, perhaps even keeping an eye on CLDC and Sun's Connected Device Configuration, (CDC).  Attention to these would ease upgrading efforts like mine to incorporated NetRexx's "latest and greatest" improvements as these evolve.

On Wed, Oct 5, 2011 at 3:02 AM, Mike Cowlishaw <[hidden email]> wrote:

> Is there any particular reason why there are no Rexx
> constructors for the wrapper classes (Byte, Integer, etc.)?
> Do you see any problem with adding them?

Not absolutely certain, but I don't think they existed originally.  But if they
did I suspect I would not have added them because then loading the Rexx class
would pull in the others.  That would slow down startup, even if they were on
the local machine.  If they were not in the JRE then that would mean hauling
them across the internet if used in an applet (and broadband was rare, then).

In general I tried to make the Rexx classes as standalone as possible, and split
them in a way to try and minimise what would get pulled in.

Mike

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[Mike Cowlishaw]

George, yes .. NetRexx was/is used on the Lego Mindstorms devices, for example.

 

Keeping the core requirement(s) small is always going to be a performance plus, regardless of the platform.

 

Mike

---

From: [hidden email] [mailto:[hidden email]] On Behalf Of George Hovey
Sent: 05 October 2011 15:57
To: IBM Netrexx
Subject: Re: [Ibm-netrexx] New Construct

Hi Mike,
Re

"In general I tried to make the Rexx classes as standalone as possible, and split them in a way to try and minimise what would get pulled in."

and Kermit's inquiry about adding Rexx constructors.

I'm in the midst of an effort to port NetRexx to a device operating under Sun's Connected Limited Device Configuration (CLDC).  [http://shap.inf.tu-dresden.de/]  As you know, this is for severely memory-constrained devices and makes available only a handful of Java classes.

It has long been my dream to port NetRexx to a JVM operating in a Field Programmable Gate Array (FPGA), as this would have some important laboratory applications (and support the luxurious programming environment to which I've become accustomed!).  Before I saw the NetRexxR source I feared I would need to incorporate many Java classes which would in turn drag in more, until the whole thing ballooned out of control.

I was relieved to discover that NetRexxR uses Java very sparingly.  The collection classes needed -- Vector, Hashtable, etc -- are included in CLDC.  The I/O classes are not, but they have (pretty much) direct replacements in CLDC.  I still have some issues related to Ask but, I think, don't involve NetRexx.  The actual changes required are rather small (though the background reading was not 8-) ).

I hope our architects will keep in mind your "principle of parsimony" with respect to use of Java classes in the runtime, perhaps even keeping an eye on CLDC and Sun's Connected Device Configuration, (CDC).  Attention to these would ease upgrading efforts like mine to incorporated NetRexx's "latest and greatest" improvements as these evolve.

On Wed, Oct 5, 2011 at 3:02 AM, Mike Cowlishaw <[hidden email]> wrote:

> Is there any particular reason why there are no Rexx
> constructors for the wrapper classes (Byte, Integer, etc.)?
> Do you see any problem with adding them?

Not absolutely certain, but I don't think they existed originally.  But if they
did I suspect I would not have added them because then loading the Rexx class
would pull in the others.  That would slow down startup, even if they were on
the local machine.  If they were not in the JRE then that would mean hauling
them across the internet if used in an applet (and broadband was rare, then).

In general I tried to make the Rexx classes as standalone as possible, and split
them in a way to try and minimise what would get pulled in.

Mike

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[Aviatrexx]

On 10/5/11 19:08 Mike Cowlishaw said:
> George, yes .. NetRexx was/is used on the Lego Mindstorms devices, for
> example.

Always wanted one of those.  Wonder if I can convince my CFO that it's
a legitimate business expense for R&D... ;-)

-Chip-

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