Implemented tabular style, for appropriate tables. Turned out to be more robust than I anticipated.

pretty.lua

@@ -283,7 +283,7 @@ local function align_into_columns (l, start_i, stop_i)
     local start_i, stop_i = start_i or 1, stop_i or #l
 
 	assert(type(start_i)	== 'number')
-    assert(type(start_i) == 'number')
+	assert(type(stop_i)	== 'number')
 
     -- Find columns
     local columns = nil
@@ -328,6 +328,46 @@ local function align_into_columns (l, start_i, stop_i)
 	end
 end
 
+local function align_into_tabular_style (l, start_i, stop_i)
+	-- Adds alignment after seperators, to create nicely aligned tabular-format.
+
+    -- Argument fixing and Error Checking
+	local start_i, stop_i = start_i or 1, stop_i or #l
+
+	assert(type(l)	== 'table')
+	assert(type(start_i)	== 'number')
+	assert(type(stop_i)	== 'number')
+	assert(type(l[start_i])	== 'table' and l[start_i][1]	== 'indent')
+	assert(type(l[stop_i])	== 'table' and l[stop_i][1]	== 'unindent')
+
+	-- Calculate where to insert new alignment.
+	local indent, key_nr, index_of_last_meta, insert_later  =  0, 0, 1, {}
+	for i = start_i + 1, stop_i - 1 do
+		if type(l[i]) ~= 'table' then
+			-- Do nothing
+		elseif l[i][1] == 'indent' then
+			indent =  indent + 1
+			if indent == 1 then  key_nr = 1  end
+			index_of_last_meta = i
+		elseif l[i][1] == 'unindent' then
+			insert_later[#insert_later+1] = {'align', 'end_subtable_'..key_nr, width_of_strings_in_l(l, index_of_last_meta+1, i), i}
+			index_of_last_meta, key_nr  =  i, key_nr + 1
+			indent =  indent - 1
+		elseif l[i][1] == 'seperator' and indent ~= 0 then
+			insert_later[#insert_later+1] = {'align', 'key_'..key_nr, width_of_strings_in_l(l, index_of_last_meta+1, i), i+1}
+			index_of_last_meta, key_nr  =  i, key_nr + 1
+		end
+    end
+	-- Insert new alignment.
+	for i = #insert_later, 1, -1 do
+		local dat = insert_later[i]
+		table.insert(l, dat[#dat], dat)
+		dat[#dat] = nil
+	end
+	-- Fix that alignemnt
+	return fix_alignment(l, start_i)
+end
+
 local function fix_seperator_info (l, indent_char, max_depth)
 
     -- Error Checking
@@ -440,7 +480,7 @@ local function format_table (t, depth, l)
     -- Decide for short or long table formatting.
     local table_width  =  width_of_strings_in_l(l, start_of_table_i)
     if table_width <= MAX_WIDTH_FOR_SINGLE_LINE_TABLE then
-        -- Is short table: Ignore the "width of key"-shit
+        -- Is short table: Ignore "width of key".
         l[start_of_table_i][3] = 'inline'
         ignore_alignment_info(l, start_of_table_i)
     elseif table_info.is_leaf_node then
@@ -448,14 +488,15 @@ local function format_table (t, depth, l)
         -- NOTE: Currently we only allow leaf-nodes to format into columns, due
         -- to issues with table alignment.
         align_into_columns(l, start_of_table_i)
+	elseif table_info.is_tabular then
+		align_into_tabular_style(l, start_of_table_i, #l)
     else
         -- Is long table: Fix whitespace alignment
         fix_alignment(l, start_of_table_i)
     end
 end
 
--- Formatting Strings
+-- Formatting coroutine
-
 
 local function format_coroutine (value, depth, l)
     -- Formats a coroutine. Unfortunantly we cannot gather a lot of information
@@ -471,6 +512,8 @@ local function format_coroutine (value, depth, l)
     l[#l+1] = tostring(value):sub(9)
 end
 
+-- Formatting primitive
+
 local function format_primitive (value, depth, l)
     -- Error check
     assert(type(depth) == 'number' and type(l) == 'table')

test/test_pretty.lua

@@ -227,12 +227,6 @@ format_test {
     expect = '{ [1] = 1, [\'whatever\'] = false }',
 }
 
-format_test {
-    -- Table view, with indent.
-    input  = { { a = 'hello', b = 'hi' }, { a = 'hi', b = 'hello' } },
-    expect = '{\n    { a = \'hello\', b = \'hi\'    },\n    { a = \'hi\',    b = \'hello\' }\n}',
-}
-
 format_test {
     name = 'Proper alignment when using unicode characters as keys',
     input  = {
@@ -243,8 +237,11 @@ format_test {
     expect = '{\n    djævle = \'dyr?\',\n    europa = \'måne\',\n    øå     = \'en å på en ø?\'\n}',
 }
 
+--------------------------------------------------------------------------------
+-- Pattern specific table display.
+
 format_test {
-    name = 'Format table into columns, if leaf node',
+    name = 'Column style',
     input = {
 		'hello',	'world',	'how',
 		'is',	'it',	'going?',
@@ -255,6 +252,72 @@ format_test {
     expect = '{\n    \'hello\', \'world\',       \'how\',\n    \'is\',    \'it\',          \'going?\',\n    \'Im\',    \'doing great\', \'thanks\',\n    \'that\',  \'was\',         \'what\',\n    \'I\',     \'were\',        \'expecting\'\n}',
 }
 
+format_test {
+    name = 'Column style with trailing last row',
+    input = {
+		'hello',	'world',	'how',
+		'is',	'it',	'going?',
+		'Im',	'doing great',	'thanks',
+		'that',	'was',	'what',
+		'I'
+    },
+    expect = '{\n    \'hello\', \'world\',       \'how\',\n    \'is\',    \'it\',          \'going?\',\n    \'Im\',    \'doing great\', \'thanks\',\n    \'that\',  \'was\',         \'what\',\n    \'I\'\n}',
+}
+
+format_test {
+	name = 'Tabular style with strings left aligned',
+    input  = {
+		{ a = 'hello',	b = 'hi'	},
+		{ a = 'hi',	b = 'hello'	}
+	},
+    expect = '{\n    { a = \'hello\', b = \'hi\'    },\n    { a = \'hi\',    b = \'hello\' }\n}',
+}
+
+format_test {
+	name = 'Tabular style with subtables in keys',
+    input  = {
+		[false]	= { a = 'hi',	b = 'hello'	},
+		[true]	= { a = 'hello',	b = 'hi'	}
+	},
+    expect = '{\n    [false] = { a = \'hi\',    b = \'hello\' },\n    [true]  = { a = \'hello\', b = \'hi\'    }\n}',
+}
+
+format_test {
+	name = 'Tabular style also works with strange keys',
+    input  = {
+		{ [false] = 'hi',	[true] = 'hello',	},
+		{ [false] = 'hello',	[true] = 'hi',	}
+	},
+    expect = '{\n    { [false] = \'hi\',    [true] = \'hello\' },\n    { [false] = \'hello\', [true] = \'hi\'    }\n}',
+}
+
+format_test {
+	name = 'Tabular style also works with lists',
+    input  = {
+		{ 'hello',	'world', 	'how is things?'	},
+		{ 'hi',	'planetdroid',	'sup?'	}
+	},
+    expect = '{\n    { \'hello\', \'world\',       \'how is things?\' },\n    { \'hi\',    \'planetdroid\', \'sup?\'           }\n}',
+}
+
+format_test {
+	name = 'Tabular style with numbers right aligned',
+    input  = {
+		{ x =	 140,	y =	 72,	z =	 31	},
+		{ x =	 5010,	y =	 1,	z =	 314	}
+	},
+    expect = '{\n    { x =  140, y = 72, z =  31 },\n    { x = 5010, y =  1, z = 314 }\n}',
+}
+
+format_test {
+	name = 'Tabular style with small subtables',
+    input  = {
+		{ a = 'hel',	x = {b = 'abc',	c = 'yo'	}	},
+		{ a = 'hi',	x = {b = 'yo',	c = 'abc'	}	}
+	},
+    expect = '{\n    { a = \'hel\', x = { b = \'abc\', c = \'yo\'  } },\n    { a = \'hi\',  x = { b = \'yo\',  c = \'abc\' } }\n}',
+}
+
 --------------------------------------------------------------------------------
 -- Table recursion