🚀 go-pugleaf

Here is a good candidate for the silliest troff preprocessor of the year.
Tbl tells troff how to format tables.  Eqn tells troff how to format
equations.  The following is a preprocessor, written in awk, that tells
troff how to format... text!?!  It's very simple, just doing vanilla
filling and justification.  Works all right, although as it stands
it's just a silly and slow way of doing something troff does anyway.
A fancier version actually might be useful if you wanted to do something
radically unusual (e.g. fill/justify to non-rectangular boundaries).
Don't expect me to write it!

-----
BEGIN {
	print ".nf"
	print ".ds l \""	# partial output line
	print ".nr w 0"		# width of partial output line
	print ".nr n 0"		# number of words in partial output line
	print ".nr L 3i"	# line length
	print ".ds s \"\\\\h'\\\\ngu'"	# interword spacing sequence

	print ".de aw"		# add word to accumulating line
	print ".if \\\\nwu+\\\\w'\\\\$1'u+\\\\w'\\\\ 'u>\\\\nLu .ff f"
	print ".ie '\\\\*l'' \\{\\"
	print ".ds l \\\\$1"
	print ".nr w \\\\w'\\\\$1'u\\}"
	print ".el \\{\\"
	print ".as l \"\\\\\\\\*s\\\\$1"
	print ".nr w \\\\nwu+\\\\w'\\\\$1'u+\\\\w'\\ 'u\\}"
	print ".nr n +1"
	print ".."

	print ".de ff"		# flush accumulating line, arg is full or not
	print ".if !'\\\\*l'' \\{\\"
	print ".nr n -1"
	print ".ie '\\\\$1'f' .nr g \\\\nLu-\\\\nwu/\\\\nnu"
	print ".el .nr g 0"
	print ".nr g +\\\\w'\\\\ 'u"
	print "\\\\*l"
	print ".ds l \""
	print ".nr n 0"
	print ".nr w 0 \\}"
	print ".."
}
/^$/ {
	print ".ff p"
	print
}
/^\./ {
	# All formatting requests cause break and are then passed through.
	print ".ff p"
	print
}
/^[^.]/ {
	for (n = 1; n <= NF; n++)
		print ".aw " $n
}
END {
	print ".ff p"
}
-----
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry