AlignColumns := proc( txt, align :: { "left", "right", "centre" } := "centre" )
	uses StringTools;

	# Get a list of lists of fields
	local A := map( Split, Split( txt ), "$" );

	# Calculate the column width
	local width := 1 + max( map( L -> max( map( length, L ) ), A ) );

	# Add spacing according to the requested type of alignment
	if align = "left" then
		local J := map( line -> map( PadRight, line, width ), A )
	elif align = "right" then
		J := map( line -> map( PadLeft, line, width ), A )
	else
		J := map( line -> map( Center, line, width ), A )
	end if;

	# Join up the fields in each line.
	J := map( cat@op, J );

	# Re-assemble the lines into a single string.
	Join( J, "\n" )
end proc: