#!/bin/perl
## Licensed under the terms of http://www.apache.org/licenses/LICENSE-2.0

# Convert javacc token format to BNF

$/ = undef ;
$_ = <> ;
s!//.*!!g ;
s!\r!!g ;
s/\n+/\n/g ;
s/^\n// ;

#@t = split(/\n(?=\<|\[)/, $tokens) ;
@t = split(/\n/) ;

## for $t (@t)
## {
##     ($tokenname,$tokenbody) = split(/::=/, $t) ;	
##     print $tokenname,"\n" ;
##     
## }

# Rewrite to XML BNF
##   #xN // [a-zA-Z], [#xN-#xN] // [abc], [#xN#xN#xN] //
##   [^a-z], [^#xN-#xN] // [^abc], [^#xN#xN#xN] 

# Rules
# 1 --  ~["X","Y"] => [^XY]
# 2 --  ["a"-"z","A"-"Z"] => [a-zA-Z]
# 3 --  ["!","&"] => [!&]
# 4 --  \uXXXX => #xXXXX

## Rule 1
s/~\[/\[^/g ;

## Rule 2
s/\["([^"]*)"-"([^"]*)"\]/\[$1-$2\]/g ;

## Rule 3
## s/\[.*"([^\],"]*)".*\]/\[$1\]/g ;

## Rule 4
s/\\u(....)/#x$1/g ;

print $_ ;