merits of Lisp vs Python

[Ken Tilton]

Kay Schluehr wrote:
> Ken Tilton schrieb:
> 
> 
>>Looks promising. How does a generic engine that sees only a solution (a
>>list of mathematical expressions and for each the transformations,
>>results, and opnds logged by individual TF functions) build up this
>>environment such that it has named attributes such as signed-value?
> 
> 
> Most likely it doesn't since there is no such engine. Instead local
> rules and combinators are encoded in classes. Hence there is nothing
> but an object tree and actions are threaded through recursive method
> calls.

Most likely that is the engine of which I was speaking. :) Why does the 
engine consisting of "internal" methods make it not an engine? I think 
you saw the word "engine" and assumed I did not understand OO design. I 
feel a Naggum coming on...

kt

ps. This won't make sense unless you know about my Cells project, but 
the solution to a /problem/ which has attributes expr and instructions, 
is a declarative attribute of a problem. But that attribute is coded 
essentially like this:

(defclass problem ()
    ....
    (solution :accessor solution
              :initform (c-formula ()
                            (solve (expr self) (instructions self)))))

k

> 
> This implies that the generic reverse function is just the dual of a
> method call:
> 
> def reverse(expr):
>      return expr.reverse()
> 
> What expr does depends on the internal representation encoded in the
> class of expr. This also implies that not only the form of the
> expression is significant but also its ( dynamic ) type.
> 

-- 
Algebra: http://www.tilton-technology.com/LispNycAlgebra1.htm

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