NEM 3Mar2005: Here's a very simple parser for the BibTeX bibliography database format. It's rather braindead at the moment, and is really not much more than a tokeniser. To use it, call bibtex::parse with the contents of a database, and you'll get back a list of entries. Each entry is itself a list of three elements: type (e.g. article, thesis, etc), key (whatever key it was given in the database), and a final list of key/value pairs (in dict form) representing the record. It doesn't handle BibTeXs (or TeXs) insane file format fully, and doesn't handle @string macros etc. There may well be further restrictions on what it can cope with. It suffices for what I need it for though -- a quick and dirty hack to dump a bibtex db to a website. Anyway, enjoy!
# bibtex.tcl --
#
# A basic parser for BibTeX bibliography databases.
#
# Copyright (c) 2005 Neil Madden.
# License: Tcl/BSD style.
package require Tcl 8.4
package provide bibtex 0.1
namespace eval bibtex {
proc parse {bibtex} {
set ret [list]
foreach block [lrange [split $bibtex @] 1 end] {
if {[regexp {([^\{]+)\{([^,]+),(.*)\}[^\}]*} $block -> type key rest]} {
lappend ret [list [Tidy $type] [string trim $key] [ParseBlock $rest]]
} else {
puts stderr "Skipping: $block"
}
}
return $ret
}
proc Tidy {str} {
string tolower [string trim $str]
}
proc ParseBlock {block} {
set ret [list]
set index 0
while {1} {
if {[regexp -start $index -indices -- {(\S+)[^=]*=(.*)} $block -> \
key rest]} {
foreach {ks ke} $key { break }
set k [Tidy [string range $block $ks $ke]]
foreach {rs re} $rest { break }
foreach {v index} \
[ParseBibString $rs [string range $block $rs $re]] \
{ break }
lappend ret $k $v
} else { break }
}
return $ret
}
proc ParseBibString {index str} {
set count 0
set retstr ""
set escape 0
foreach char [split $str ""] {
incr index
if {$escape} {
set escape 0
} else {
if {$char eq "\{"} {
incr count
continue
} elseif {$char eq "\}"} {
incr count -1
if {$count < 0} { incr index -1; break }
continue
} elseif {$char eq ","} {
if {$count == 0} { break }
} elseif {$char eq "\\"} {
set escape 1; continue
} elseif {$char eq "\""} { continue }
append retstr $char
}
}
regsub -all {\s+} $retstr { } retstr
return [list [string trim $retstr] $index]
}
}