[Push] Top Level Code or Exec?

[Rud Merriam]

Thanks, Lee & Maarten,

The confusion goes back to my original email last week. I was assuming that
CODE.DO and CODE.DO* executed the code on their stack directly since the
documentation did not say they should move the list to the EXEC stack. The
documentation for DO*RANGE & DO*TIMES said this explicitly so I assumed with
the others not saying it they didn't move the list. 

Got the 'float power' example in the documentation working tonight which I
think is complicated enough that the interpreter is working well. I did get
hung up a bit on the example until I realized it needed an ARG after the
FLOAT.DEFINE to put the starting value back on the stack. (I implemented
DEFINE to pop the value from the stack when it is being defined. Is that
wrong?)

Thought maybe you'd be interested to know that I setup unit tests using a
C++ framework called TUT. There is a unit test for each instruction that
I've implemented, plus list manipulation routines. The unit test checks the
key points like the values on the stacks and stack depths. Unit testing was
just coming into popularity as I was winding down my employment period (I am
now retired). After I got the example working I ran all the unit tests and
all but one worked and it just needed parens around the input list. 

Now onto genetic operators...

 
 - 73 - 
Rud Merriam K5RUD 
http://mysticlakesoftware.com/


> -----Original Message-----
> From: Lee Spector [mailto:lspector at hampshire.edu] 
> Sent: Monday, April 19, 2010 8:29 PM
> To: Maarten Keijzer
> Cc: push at lists.hampshire.edu; Rud Merriam
> Subject: Re: [Push] Top Level Code or Exec?
> 
> 
> 
> Same deal in the other implementations that I know about, 
> although not implemented with CODE.DO* (although that is 
> indeed elegant). 
> 
> It has to go on to the EXEC stack to be executed, and putting 
> it on the CODE stack is handy for programs that manipulate 
> their own code. In several implementations the push onto the 
> CODE stack (and the post-run popping of the CODE stack, which 
> in Maarten's implementation will also be accomplished by 
> CODE.DO*) can be turned on or off with a parameter.
> 
>  -Lee
> 
> On Apr 19, 2010, at 4:01 PM, Maarten Keijzer wrote:
> 
> > 
> > We wanted to have the program code on the code stack for 
> the program 
> > to
> > manipulate. Although code on the exec stack could in 
> principle copy itself on 
> > the code stack (with some trouble), we thought it would be 
> easiest to push the 
> > code to be executed both on the code stack AND on the exec stack.
> > 
> > So that's what we do. In the C++ version, this is called the push 
> > calling
> > convention, and it is implemented by pushing code on the 
> CODE stack, and 
> > pushing the CODE.DO* instruction on the exec stack.
> > 
> > hth,
> > 
> > -Maarten-
> > 
> > 
> > On Monday 19 April 2010 09:46:21 pm Rud Merriam wrote:
> >> The documentation on Push3 is a bit confusing as to where 
> to load a 
> >> program.
> >> 
> >> In discussing configuration and later in the Factorial example the 
> >> implication is that a program is read from a file and then pushed 
> >> onto the CODE stack.
> >> 
> >> But the description of the execution environment - where 
> the CODE and 
> >> EXEC execution is contrasted - seems to imply a program is pushed 
> >> onto the EXEC stack. This is in the Push Concepts section.
> >> 
> >> I'm guessing the pushing to CODE is the approach used, although it 
> >> seems inconsistent with the switch to EXEC in Push3.
> >> 
> >> 
> >> - 73 -
> >> Rud Merriam K5RUD 
> >> http://mysticlakesoftware.com/
> >> 
> >> 
> > _______________________________________________
> > Push mailing list
> > Push at lists.hampshire.edu 
> > https://lists.hampshire.edu/mailman/listinfo/push
> 
> --
> Lee Spector, Professor of Computer Science
> School of Cognitive Science, Hampshire College
> 893 West Street, Amherst, MA 01002-3359
> lspector at hampshire.edu, http://hampshire.edu/lspector/
> Phone: 413-559-5352, Fax: 413-559-5438
> 
> Check out Genetic Programming and Evolvable Machines: 
> http://www.springer.com/10710 - http://gpemjournal.blogspot.com/
> 
> _______________________________________________
> Push mailing list
> Push at lists.hampshire.edu 
> https://lists.hampshire.edu/mailman/listinfo/push
>