#!/bin/sh

#fptags - Create an emacs tags file for functional programs

#Please send me a copy of any modifications you make.
#Denis Howe <dbh@doc.ic.ac.uk>
#0.00 20-Sep-1991 created
#0.01 09-Apr-1992 don't count ==, <=, >= as definition
#0.02 09-Feb-1994 fix bug in fix 0.01.  Add /=.

# partain: got it from wombat.doc.ic.ac.uk:pub

#The algorithm for spotting identifiers is crude to the point of
#vulgarity.  Any line containing an = is assumed to define an
#identifier.  If there are no non-white characters before the = then
#the definition is assumed to start on the previous line.  White
#characters are space, tab and > (for literate programs).  The =s in
#the relations ==, <=, >= and /= are temporarily transformed while
#searching for =s.

#The tags file is not in the format produced by ctags but rather,
#that produced by etags and used by GNU-Emacs's find-tag command.

#Does not tag constructors in sum data types.

#The tags file, TAGS, is created in the current directory.  It
#contains an entry for each argument file.  The entry begins with a
#line containing just ^L.  The next line contains the filename, a
#comma and the number of following bytes before the next ^L or EOF.
#Subsequent lines should give the location within the argument file of
#identifier definitions.  Each line contains a prefix of a line from
#the argument file, a ^?, the line number within the argument file, a
#comma and the position of the start of that line in the argument file
#(first character = 1).

[ -z "$1" ] && echo usage: $0 files && exit 1
exec > TAGS
tf=/tmp/fp$$
for f
do	echo ""
	sed 's/==//g
	s/>=/>/g
	s/<=/</g
	s|/=|/|g' $f | awk '
	/^[> 	]*=/{ print prevline "" NR-1 "," prevpos; }
	/[^> 	].*=/{ print $0 "" NR "," pos; }
	{ prevline = $0; prevpos = pos; pos += length($0)+1; }
	' pos=1 | sed 's/[	 )]*=.*//
	s//=/g' > $tf
	echo -n $f,; echo `wc -c < $tf`	#lose spaces
	cat $tf
done
rm -f $tf