#!/bin/sh
# t -- tag jumping in ed(1)
#
# core concept:
#    we simulate a "tag stack" by recursing within ed(1). When you're done
#    at this tag, just `q` out of there!
#
#    NOTE: unfortunately, we can't get ed(1) to jump to the location within
#    the file (without maybe some crazy hacks like using a fifo for stdin..
#    but even that's likely to fail). The best we can do is output the cmd
#    to search!
die() {
	echo "$*" 1>&2
	exit 1
}

[ -z "$1" ] && die "usage: t TAG"
[ ! -e "tags" ] && die "no ./tags file"

TLINE=$(grep "^$1	" tags | head -n 1)
[ -z "$TLINE" ] && die "tag not found"

file=$(echo "$TLINE" | cut -f2)
regex=$(echo "$TLINE" | cut -f3)

# trim the universal ctags regex bits
# also convert it to a real regex by escaping any special chars!
regex=$(echo "$regex" | sed \
    -e 's/;"$//' \
    -e 's/\\/\\\\/g' \
    -e 's/\*/\\*/g' \
    -e 's/\[/\\[/g' \
    -e 's/\]/\\]/g' \
    -e 's/\./\\./g')

echo "jumping to $file, search the following:"
echo "$regex"
exec e "$file"