awesome/lib/gears/protected_call.lua

58 lines
1.8 KiB
Lua

---------------------------------------------------------------------------
-- @author Uli Schlachter
-- @copyright 2016 Uli Schlachter
-- @utillib gears.protected_call
---------------------------------------------------------------------------
local gdebug = require("gears.debug")
local tostring = tostring
local traceback = debug.traceback
local unpack = unpack or table.unpack -- luacheck: globals unpack (compatibility with Lua 5.1)
local xpcall = xpcall
local protected_call = {}
local function error_handler(err)
gdebug.print_error(traceback("Error during a protected call: " .. tostring(err), 2))
end
local function handle_result(success, ...)
if success then
return ...
end
end
local do_pcall
if not select(2, xpcall(function(a) return a end, error, true)) then
-- Lua 5.1 doesn't support arguments in xpcall :-(
do_pcall = function(func, ...)
local args = { ... }
return handle_result(xpcall(function()
return func(unpack(args))
end, error_handler))
end
else
do_pcall = function(func, ...)
return handle_result(xpcall(func, error_handler, ...))
end
end
--- Call a function in protected mode and handle error-reporting.
-- If the function call succeeds, all results of the function are returned.
-- Otherwise, an error message is printed and nothing is returned.
-- @tparam function func The function to call
-- @param ... Arguments to the function
-- @return The result of the given function, or nothing if an error occurred.
function protected_call.call(func, ...)
return do_pcall(func, ...)
end
local pcall_mt = {}
function pcall_mt:__call(...)
return do_pcall(...)
end
return setmetatable(protected_call, pcall_mt)
-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80