---------------------------------------------------------------------------
-- @author Uli Schlachter
-- @copyright 2010 Uli Schlachter
-- @release @AWESOME_VERSION@
-- @module gears.debug
---------------------------------------------------------------------------

local error = error
local tostring = tostring
local traceback = debug.traceback
local print = print
local type = type
local pairs = pairs

local debug = {}

--- Check that the given condition holds true, else throw an error
--
-- @param cond If this is false, throw a lua error with a backtrace.
-- @param[opt] message Message to print in the error (optional).
function debug.assert(cond, message)
    local message = message or cond
    if not cond then
        error(traceback("Assertion failed: '" .. tostring(message) .. "'"))
    end
end

--- Given a table (or any other data) return a string that contains its
-- tag, value and type. If data is a table then recursively call d_raw
-- on each of its values.
-- @param data Value to inspect.
-- @param shift Spaces to indent lines with.
-- @param tag The name of the value.
-- @return a string which contains tag, value, value type and table key/value
-- pairs if data is a table.
local function dump_raw(data, shift, tag)
    local result = ""

    if tag then
        result = result .. tostring(tag) .. " : "
    end

    if type(data) ~= "table" then
        return result .. tostring(data) .. " (" .. type(data) .. ")"
    end

    shift = (shift or "") .. "  "
    for k, v in pairs(data) do
        result = result .. "\n" .. shift .. dump_raw(v, shift, k)
    end

    return result
end

--- Inspect the value in data.
-- @param data Value to inspect.
-- @param tag The name of the value.
-- @return a string that contains the expanded value of data.
function debug.dump_return(data, tag)
    return dump_raw(data, nil, tag)
end

--- Print the table (or any other value) to the console.
-- @param data Table to print.
-- @param tag The name of the table.
function debug.dump(data, tag)
    print(debug.dump_return(data, tag))
end

return debug

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