---------------------------------------------------------------------------
-- @author Julien Danjou <julien@danjou.info>
-- @copyright 2009 Julien Danjou
-- @release @AWESOME_VERSION@
---------------------------------------------------------------------------

-- Grab environment we need
local setmetatable = setmetatable
local ipairs = ipairs
local unpack = unpack
local capi = { key = key }
local util = require("awful.util")

--- Key helper for awful
module("awful.key")

--- Modifiers to ignore
ignore_modifiers = { "Lock", "Mod2" }

--- Create a new key to use as binding.
-- This function is useful to create several keys from one, because it will use
-- the ignore_modifier variable to create more key with or without the ignored
-- modifiers activated.
-- For example if you want to ignore CapsLock in your keybinding (which is
-- ignored by default by this function), creatina key binding with this function
-- will return 2 key objects: one with CapsLock on, and the other one with
-- CapsLock off.
-- @see C api key() function for parameters.
-- @return A table with one or several key objects.
function new(mod, ...)
    local ret = {}
    local subsets = util.subsets(ignore_modifiers)
    for _, set in ipairs(subsets) do
        ret[#ret + 1] = capi.key(util.table.join(mod, set), unpack(arg))
    end
    return ret
end

--- Compare a key object with modifiers and key.
-- @param key The key object.
-- @param pressed_mod The modifiers to compare with.
-- @param pressed_key The key to compare with.
function match(key, pressed_mod, pressed_key)
    -- First, compare key.
    if pressed_key ~= key.key then return false end
    -- Then, compare mod
    local mod = key.modifiers
    -- For each modifier of the key object, check that the modifier has been
    -- pressed.
    for _, m in ipairs(mod) do
        -- Has it been pressed?
        if not util.table.hasitem(pressed_mod, m) then
            -- No, so this is failure!
            return false
        end
    end
    -- If the number of pressed modifier is ~=, it is probably >, so this is not
    -- the same, return false.
    if #pressed_mod ~= #mod then
        return false
    end
    return true
end

setmetatable(_M, { __call = function(_, ...) return new(unpack(arg)) end })

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