[pypy-dev] __builtin__ module

[Bengt Richter]

At 18:15 2003-01-22 +0100, Thomas Heller wrote:
>Boyd Roberts <boyd at strakt.com> writes:
>
>> Thomas Heller wrote:
>> 
>> >I don't think so. For me, this is a fine implementation of chr():
>> >
>> >def chr(i):
>> >    return "\x00\x01\x02x03...\xFF"[i]
>> >
>> 
>> That's dreadful.
>> 
>>     def chr(i):
>>         return'%c' % i
>> 
>
>Maybe, but you probably got my point...

I see four issues in the above that might be worth some guiding
words from the leaders[a]: 1) premature optimization, 2)appropriate
level of Python code for coding PyPython, 3) appropriate definition
semantics, 4) dependencies in definitions.

1) Standard advice, presumably

2) What kinds of constructs will be best for Psyco to deal with? When
    coding the definition of something, should one ask:
    2a) Is the thing being coded part of core minimal PyPython, so
        coding should be limited to a Python subset, or
    2b) Is the thing being coded at the next level, so that the full
        language can be presumed to be available?
    2c) How does one know whether a thing belongs to 2a or 2b, or
        is this distinction really necessary in the current thinking?

3) When is it good to define primitively, like Thomas's definition,
   and when is it good to define in terms of a composition implicitly
   delegating to existing function(s), like Boyd's? And should one be
   careful as to whether the functions one is depending on belong to 2a or 2b?

4) Should a dependency tree be documented as we go, e.g., to avoid hidden
   circular dependencies in delegated functionality, but also to make
   clear levels of primitiveness? (BTW, ISTM this would help in any future
   attempt to factor out the implementation of a primitive core functionality).

   The two definitions of chr() above are examples of primitive vs
   composite/delegating definitions, which is what brought this to mind
   (which is not to say that the "primitive" definition doesn't depend
   on anything, but it's composing with lower level primitives).

Regards,
Bengt

[a] Should I have cc'd Armin, Chris, and Holger?
I.e., would that have been courtesy or redundant annoyance?