Hendrik van Rooyen wrote:
"Terry Reedy" <[EMAIL PROTECTED]> wrote:
Hendrik van Rooyen wrote:
I am using the term in the restricted sense of Python writing Python source.
Given that, can anybody think of an example that you could not do with
a class? (excepting the "stored procedure" aspect)
I am not sure I understand your question.
def iterize(recursive_function_text):
<code to parse input and fill a template>
return equivalent_iterative_function_text
where input and output are both Python code. If one were to implement
this by compiling the input to AST form and then walking the tree, the
AST node classes would be involved, but I would scarely say the
translation was done by the classes, as opposed to functions which might
or might not be attacked to a class as methods.
I am not sure I understand the answer - if the input and output are both
bits of python source, then the output must be stored and evaluated or
imported to get it executed, right?
Yes. I would couple the above with
def iterfunc(rtext):
itext = iterize(rtext)
<code to exec itext to make function object>
return ifunc
The text transform is the hard part and should be separate for testing
and possible output for optimization or reuse elsewhere.
The scenario I have in mind is
1. write program with recursive function and test
2. triple-quote function text and wrap with function call; retest.
Yes, Steven's tail recursion example is example of above.
Now if this is the case, my question has to do with whether it is always
possible to put the equivalent code in a class, and instantiating it so that
it is either immediately executed or ready for immediate execution. My
gut feel tells me that it should always be possible, but I have often had
wrong hunches.
Not sure if this makes it any clearer.
I am not sure what you mean by 'do with a class'. A class is an active
namespace in that it creates and initializes instances and does a bit
extra with method calls, but it is otherwise a passive namespace container.
Any code can be put into class methods, but I do not see any reason to
do so for this example.
Terry Jan Reedy
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