Insert an empty row table when tab.nextrow is called and there is

nothing in the current row yet. This allows using #t or ipairs to get
the number of rows that have been filled by the user. t.rows is the
index number of the next row that will be filled in, or the one that is
currently being filled in if something has already been entered.
t.rows == #t + 1 means that we've finished with the previous row, but we
don't want to count a new (blank) row until we've started filling
something in.

nselib/tab.lua

@@ -40,8 +40,6 @@ end
 -- @param c The column position at which to add the item.
 function add(t, c, v)
 	assert(t)
-	assert(v)
-	assert(t['rows'])
 	assert(type(v) == "string")
 
 	-- add a new row if one doesn't exist
@@ -73,6 +71,7 @@ end
 function nextrow(t)
 	assert(t)
 	assert(t['rows'])
+	t[t['rows']] = t[t['rows']] or {}
 	t['rows'] = t['rows'] + 1
 end
 
@@ -83,16 +82,13 @@ end
 -- @param t The table.
 function dump(t)
 	assert(t)
-	assert(t['rows'])
 
 	local column_width = {}	
 	local num_columns = 0
 	local buf = strbuf.new()
-	local len
 
 	-- find widest element in each column
-	for i = 1, t['rows'] do
-		local row = t[i]
+	for i, row in ipairs(t) do
 		for x, elem in pairs(row) do
 			local elem_width = string.len(elem)
 			if not column_width[x] or elem_width > column_width[x] then
@@ -105,10 +101,10 @@ function dump(t)
 	end
 
 	-- build buf with padding so all column elements line up
-	for i = 1, t['rows'] do
+	for i, row in ipairs(t) do
 		local text_row = {}
 		for x = 1, num_columns do
-			local elem = t[i][x] or ""
+			local elem = row[x] or ""
 			text_row[#text_row + 1] = elem .. string.rep(" ", column_width[x] - #elem)
 		end
 		buf = buf .. table.concat(text_row, "  ") .. "\n"