Re: HTTP GET Shakespeare

[Andreas Rottmann]

address@hidden writes:

> Hello list, I need some help.
>
> I'm following a Computer Science course material in Python and then
> try to implement the examples and exercises in Guile Scheme.
>
> Currently I'm working on a small program to get a text document from
> the Web and do some string operations with the content, but my
> implementation in Guile takes about 5-7 minutes to finish, while the
> Python version takes 6-8 seconds. Also, the printed results are
> different, but I'm more concerned about the time issue right now.
>
> Could you point me to possible mistakes I'm making here?
>
> Guile Scheme program:
> https://gist.github.com/umanomata/99f103ed686acd523d9e
>
> Python program:
> https://gist.github.com/umanomata/1dbb3beb2ce19f09fcee
>
There's a difference in algorithmic complexity here: in Scheme, you use
SRFI-1's "delete-duplicates", which is noted to be O(n^2) complexity in
the SRFI-1 specification[0]. In Python, you use set(), which is probably
implemented using a hash table, yielding roughly O(1) complexity. Since
your input set is large, it would be better to feed the read words into
a hash table, instead of using a list and SRFI-1 "delete-duplicates".

[0] http://srfi.schemers.org/srfi-1/srfi-1.html#delete-duplicates

Regards, Rotty
-- 
Andreas Rottmann -- <http://rotty.xx.vu/>