reddit-grab/table_show.lua
2015-07-05 11:43:31 +02:00

106 lines
3.2 KiB
Lua

--[[
Author: Julio Manuel Fernandez-Diaz
Date: January 12, 2007
(For Lua 5.1)
Modified slightly by RiciLake to avoid the unnecessary table traversal in tablecount()
Formats tables with cycles recursively to any depth.
The output is returned as a string.
References to other tables are shown as values.
Self references are indicated.
The string returned is "Lua code", which can be procesed
(in the case in which indent is composed by spaces or "--").
Userdata and function keys and values are shown as strings,
which logically are exactly not equivalent to the original code.
This routine can serve for pretty formating tables with
proper indentations, apart from printing them:
print(table.show(t, "t")) -- a typical use
Heavily based on "Saving tables with cycles", PIL2, p. 113.
Arguments:
t is the table.
name is the name of the table (optional)
indent is a first indentation (optional).
--]]
function table.show(t, name, indent)
local cart -- a container
local autoref -- for self references
--[[ counts the number of elements in a table
local function tablecount(t)
local n = 0
for _, _ in pairs(t) do n = n+1 end
return n
end
]]
-- (RiciLake) returns true if the table is empty
local function isemptytable(t) return next(t) == nil end
local function basicSerialize (o)
local so = tostring(o)
if type(o) == "function" then
local info = debug.getinfo(o, "S")
-- info.name is nil because o is not a calling level
if info.what == "C" then
return string.format("%q", so .. ", C function")
else
-- the information is defined through lines
return string.format("%q", so .. ", defined in (" ..
info.linedefined .. "-" .. info.lastlinedefined ..
")" .. info.source)
end
elseif type(o) == "number" or type(o) == "boolean" then
return so
else
return string.format("%q", so)
end
end
local function addtocart (value, name, indent, saved, field)
indent = indent or ""
saved = saved or {}
field = field or name
cart = cart .. indent .. field
if type(value) ~= "table" then
cart = cart .. " = " .. basicSerialize(value) .. ";\n"
else
if saved[value] then
cart = cart .. " = {}; -- " .. saved[value]
.. " (self reference)\n"
autoref = autoref .. name .. " = " .. saved[value] .. ";\n"
else
saved[value] = name
--if tablecount(value) == 0 then
if isemptytable(value) then
cart = cart .. " = {};\n"
else
cart = cart .. " = {\n"
for k, v in pairs(value) do
k = basicSerialize(k)
local fname = string.format("%s[%s]", name, k)
field = string.format("[%s]", k)
-- three spaces between levels
addtocart(v, fname, indent .. " ", saved, field)
end
cart = cart .. indent .. "};\n"
end
end
end
end
name = name or "__unnamed__"
if type(t) ~= "table" then
return name .. " = " .. basicSerialize(t)
end
cart, autoref = "", ""
addtocart(t, name, indent)
return cart .. autoref
end