forgetting state

[Dale Strickland-Clark]

"logistix" <logstx at bellatlantic.net> wrote:

>It's a feature, not a bug ;)
>
>One of the big bullet items for python is that it operates in a dynamic
>environment.  The programmer can modify the environment at runtime.  In a
>dynamic environment, you don't want to trust the system to decide what
>existing objects should be killed (other than gc) or what existing objects
>do or don't need to be fixed.  It's up to the programmer to explicitly do
>this if he/she wants to.  An even more unforgivable sin than not having the
>system "fix" broken objects/dependencies/etc is to allow the system to break
>currently functioning and running objects.  It's very difficult (probably
>impossible) to write a general-purpose, "if-it-ain't-broke-don't-fix-it"
>algorithm.   Given this, it makes sense that the only way to ensure that
>you've returned to the initial state of the environment is to kill it and
>create a new one.
>
>Now I'm not saying you need to agree with this (you obviously don't), but it
>is a genuine philosophical decision on how things should operate, as opposed
>to an oversight or bug needing to be corrected.  There are probably lisp or
>smalltalk programmers at the other end of the spectrum who think that an
>image of the enviroment should be saved automatically when you shut down the
>interpreter.  Then when you open it up again you're NOT in any sort of
>'initial state', but right where you left off, bugs and all.
>
>There are also people who get very upset that 1) there is no mechanism for
>static typing in Python, 2) there are no plans to add it, and 3) (even worst
>of all!) noone cares.  This is another philosophical decision and not an
>oversight.
>
>And, of course, with all philosophical decisions, it's really hard to prove
>who's right and who's wrong. [Except mob rule, and it looks like the mob has
>spoken.]
>

This, somewhat verbosely, completely misses the point.

If you're debugging a program and execution stops at some point, for
any reason, you don't want to have to completely leave your
development environment and restart it just so you can run from the
beginning again.

All the twaddle about dynamic environment and existing objects is
utterly irrelevant. If my program has failed, I don't want them any
more. I want a nice shiney new environment with a fresh set of
objects.

There really should be a "throw it all away and let me start again"
button.

--
Dale Strickland-Clark
Riverhall Systems Ltd