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Re: Problems with Victoria Day implementation of PCL
- To: Benoit HABERT <email@example.com>
- Subject: Re: Problems with Victoria Day implementation of PCL
- From: kanderso@DINO.BBN.COM
- Date: Wed, 20 Jun 90 10:55:36 -0400
- Cc: CommonLoops.PA@Xerox.COM
- In-reply-to: Your message of Tue, 19 Jun 90 07:46:58 +0200. <9006190546.AA25104@litp.ibp.fr>
- Redistributed: CommonLoops.PA
Date: Tue, 19 Jun 90 07:46:58 +0200
From: Benoit HABERT <firstname.lastname@example.org>
Subject: Problems with Victoria Day implementation of PCL
I am using the PCL implementation
Victoria Day to implement a parser (a chart parser, for
unification based grammars).
In the output files of the parser, I came accross items like:
Scanning Victoria-Day source files, I did not find the string
Furthermore, (make-instance 'unknown-object) triggers an error.
There is no class named "unknown-object"
While parsing the same text, with the same grammar and the same
dictionary, I noticed that the "unknown-objects" appeared
at slightly different places. For instance (I am using French
Trade-Unions manifestos to test my parser):
First parse of a text:
e<quilibre du secteur locatif #<unknown-object 130547b> entrai^\nant
As one can notice in these samples, these "unknown-objects" occur
"in bursts", then do not appear for a while, and occur again.
They replace seemingly punctuation marks which were represented
as strings so as not to interfere with Common Lisp macro-
characters. To test this hypothesis, I replaced in the test text
strings like ";" by symbols like |;| and "unknown-objects" did
not appear any more in the output files.
Another hint: I did not came accross this problem with
Have you any idea about the origin of this problem, and any solution
(apart from avoiding strings !)
Off hand, this doesn't seem like a PCL problem. Rather it seems like
a problem with your parser, or the LISP you are using, or perhaps some
interaction between them and PCL. Are these unknown-objects PCL
instance? What class are they?