> just as it is black magic for me now :D
The nice thing about this approach is the fact that it "just" piggybacks
the normal Smalltalk message sending. So you can step through it using
the Debugger - it's Smalltalk all the way down.
I still remember my first shock when (having no formal background on
parsing theory at that time) I saw the parsing tables generated by
T-Gen. Of course it was Smalltalk ... but understanding those tables was
a nightmare.
PetitParser is the gold standard here IMHO. It is able to parse
arbitrary input (compared to my block expressions only). And you can
still use the Debugger to step through the parsing process *and still
understand what's going on!*
CU,
Udo
On 23.09.14 09:54, kilon alios wrote:
just as it is black magic for me now :D
At least I get the general feeling. I am new to parsing too, so far I
have only played with regex parsing. Not the most smalltalkish way but
it works well so far.
On Tue, Sep 23, 2014 at 9:39 AM, Udo Schneider
<udo.schnei...@homeaddress.de
<mailto:udo.schnei...@homeaddress.de>> wrote:
Hi Estaban,
I think the first time I saw this pattern was in ReStore on Dolphin
Smalltalk. I didn't understand it's implementation back then. I
assume that it's similar to what I described though. But having a
Smalltalk block automagically creating the equivalent SQL SELECT
expression was like black magic at that time :-)
CU,
Udo
On 23.09.14 04:15, Esteban A. Maringolo wrote:
Excellent article.
I think GLORP uses a similar technique to setup its expressions, and
also have issues with #and:/#or: selectors due to inlining, so
it uses
AND:/#OR: instead.
Regards!
Esteban A. Maringolo
pd: Your blog and it's choosen topic made me remember
http://use-the-index-luke.com/
2014-09-22 20:48 GMT-03:00 Udo Schneider
<udo.schnei...@homeaddress.de
<mailto:udo.schnei...@homeaddress.de>>__:
All,
I just finished a blog entry. It shows how to use Smalltalk
blocks as parsers/translators. E.g. translating a Block
[:customer | (customer joinDate year is: Date
today year)]
into an SQL-like String
(YEAR(customers.joinDate) = 2014)
The SQL stuff is just an example - you can create nearly any
output.
Check out
http://readthesourceluke.__blogspot.de/2014/09/block-__translators-parsing-magic.html
<http://readthesourceluke.blogspot.de/2014/09/block-translators-parsing-magic.html>
Maybe that's old stuff for some of you - but I hope it's
interesting for some at least :-)
Comments and feedback appreciated.
CU,
Udo
