gocurcon: Google Currency Converter Scrapper

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conan
Posts: 52
Joined: Sat Oct 22, 2011 12:14 pm

gocurcon: Google Currency Converter Scrapper

Post by conan »

Hi all,

I wanted to share a tiny script which allows me to query google/finance/converter from the CLI.

It's not much of a scrapper really, but I couldn't come up with a better word to describe it. It does scrap! Really! :P

Check it here:
https://github.com/conan-lugmen/newlisp-webscraps

I have two questions regarding my code:

1. Why unify requires uppercase tokens to be able to create symbols with bind? Or maybe my question is this one: Am I correctly using bind/unify? Is that the intended use?

2. I put a check to consider a get-url not giving back a proper answer. However on some runs I've noticed I get nil results like if my check was passed by. What am I doing wrong there?

Lutz
Posts: 5279
Joined: Thu Sep 26, 2002 4:45 pm
Location: Pasadena, California
Contact:

Re: gocurcon: Google Currency Converter Scrapper

Post by Lutz »

Using uppercase letters for variables in unification, is a convention introduced from logic programming with the Prolog language.

See also here: http://en.wikipedia.org/wiki/Unificatio ... rder_terms

You are using bind with unify correctly, although instead of:

Code: Select all

(bind (unify '(From To Ammount) myArgs))
you could also use:

Code: Select all

(map set '(From To Ammount) myArgs))
and in the last case your variables don't need to be in uppercase.

hilti
Posts: 140
Joined: Sun Apr 19, 2009 10:09 pm
Location: Hannover, Germany
Contact:

Re: gocurcon: Google Currency Converter Scrapper

Post by hilti »

Thanks for this useful and small scraper.

Best wishes
Marc
--()o Dragonfly web framework for newLISP
http://dragonfly.apptruck.de

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