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/* $Id: bib.pl,v 1.1.1.1 1994/06/27 13:17:20 jan Exp $
Part of XPCE
Designed and implemented by Anjo Anjewierden and Jan Wielemaker
E-mail: jan@swi.psy.uva.nl
Copyright (C) 1994 University of Amsterdam. All rights reserved.
*/
:- module(pce_bibtex, []).
:- use_module(library(pce)).
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
This library file defines a parser for BibTeX database files. It is
intended as an example for using XPCE's text-manipulation and data
representation techniques and may be used as a starting point for
implementing a BibTeX database manager program.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
/*******************************
* DATABASE *
*******************************/
:- pce_begin_class(bibtex_db, hash_table, "BibTeX DataBase").
variable(strings, sheet, get, "Table of strings").
variable(file, file*, get, "File it was loaded from").
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
A BibTeX database is represented by a hash_table mapping keys onto
bibtex_entry objects. A bibtex_entry is subclass of class sheet.
The database as a whole also stores a sheet for the defined
string-constants as well as a reference to the file it was loaded from
(if any).
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
initialise(DB, File:[file]*) :->
"Create BibTeX database from file"::
send(DB, send_super, initialise),
send(DB, slot, strings, new(sheet)),
( File \== @default
-> send(DB, slot, file, File),
send(DB, load, File)
).
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
The database is parsed using a text_buffer. This allows us to easily
exploit the regular-expression capabilities of XPCE implemented by class
regex.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
load(DB, File:file) :->
"Load entries from file"::
new(TB, text_buffer),
send(TB, insert_file, 0, File),
send(DB, parse, TB),
free(TB).
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Toplevel loop to parse a BibTeX file. First of all, the syntax-table of
the text_buffer is modified to treat the newline as white_space,
allowing the '\s ' operator in regular expressions to include newlines.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
parse(DB, TB:text_buffer) :->
"Parse all entries from given text-buffer"::
new(Here, number(0)),
get(TB, size, Size),
send(TB, syntax, new(S, syntax_table)),
send(S, add_syntax, '\n', white_space),
repeat,
send(DB, parse_entry, TB, Here),
get(Here, value, Size), !.
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Regular expression constants for the various fields of a BibTeX file.
Note that GNU-regular expression define `syntax categories': '\s ' means
`any white character (as defined by the syntax table)', '\w' means `any
word character'. '\S ' and '\W' are negations. See class regex for a
full description.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
:- pce_global(@bibtex_head_regex,
new(regex('@\(\w+\){'))).
:- pce_global(@bibtex_key_regex,
new(regex('\s *\(\S +\)\s *,'))).
:- pce_global(@bibtex_att_regex,
new(regex('\s *\(\w+\)\s *=\s *\("\(\\"\|[^"]\)*"\|\w+\|[^,]+\)\s *,?'))).
:- pce_global(@bibtex_end_attr_regex,
new(regex('\s *}\s *'))).
parse_entry(DB, TB:text_buffer, Here:number) :->
"Parse 1 entry"::
send(@bibtex_head_regex, search, TB, Here), !,
get(@bibtex_head_regex, register_value, TB, 1, name, T0),
send(Here, value, @bibtex_head_regex?register_end),
get(T0, downcase, Type),
( Type == string
-> ( send(@bibtex_att_regex, match, TB, Here)
-> get(@bibtex_att_regex, register_value, TB, 1, name, SName),
get(@bibtex_att_regex, register_value, TB, 2, SValue),
send(DB?strings, value, SName, SValue),
send(Here, value, @bibtex_att_regex?register_end)
; send(TB, report, error, 'Illegal string at %d', Here),
fail
)
; send(@bibtex_key_regex, match, TB, Here),
get(@bibtex_key_regex, register_value, TB, 1, name, Key),
send(DB, append, Key, new(E, bibtex_entry(Type, Key))),
send(Here, value, @bibtex_key_regex?register_end),
repeat,
( send(E, parse_attribute, TB, Here)
-> ( send(@bibtex_end_attr_regex, match, TB, Here)
-> !,
send(Here, value, @bibtex_end_attr_regex?register_end)
; fail
)
; !,
send(TB, report, error, 'Cannot parse attribute at %d', Here),
fail
)
).
:- pce_end_class.
/*******************************
* ENTRY *
*******************************/
:- pce_begin_class(bibtex_entry, sheet).
initialise(E, Type:name, Key:name) :->
send(E, send_super, initialise),
send(E, value, type, Type),
send(E, value, key, Key).
parse_attribute(E, TB:text_buffer, Here:number) :->
"Parse attribute-value pair"::
send(@bibtex_att_regex, match, TB, Here),
get(@bibtex_att_regex, register_value, TB, 1, name, AName),
get(@bibtex_att_regex, register_value, TB, 2, AValue),
send(E, value, AName, AValue),
send(Here, value, @bibtex_att_regex?register_end).
:- pce_end_class.
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