lain/helpers.lua

225 lines
5.1 KiB
Lua

--[[
Licensed under GNU General Public License v2
* (c) 2013, Luca CPZ
--]]
local spawn = require("awful.spawn")
local timer = require("gears.timer")
local gdebug = require("gears.debug")
local debug = require("debug")
local io = { lines = io.lines,
open = io.open }
local pairs = pairs
local rawget = rawget
local tsort = table.sort
local unpack = unpack or table.unpack -- lua 5.1 retro-compatibility
local lgi = require("lgi")
-- Lain helper functions for internal use
-- lain.helpers
local helpers = {}
helpers.lain_dir = debug.getinfo(1, 'S').source:match[[^@(.*/).*$]]
helpers.icons_dir = helpers.lain_dir .. 'icons/'
helpers.scripts_dir = helpers.lain_dir .. 'scripts/'
-- {{{ Modules loader
function helpers.wrequire(t, k)
return rawget(t, k) or require(t._NAME .. '.' .. k)
end
-- }}}
-- {{{ File operations
-- check if the file exists and is readable
function helpers.file_exists(path)
local file = io.open(path, "rb")
if file then file:close() end
return file ~= nil
end
-- get a table with all lines from a file
function helpers.lines_from(path)
local lines = {}
for line in io.lines(path) do
lines[#lines + 1] = line
end
return lines
end
-- get a table with all lines from a file matching regexp
function helpers.lines_match(regexp, path)
local lines = {}
for line in io.lines(path) do
if string.match(line, regexp) then
lines[#lines + 1] = line
end
end
return lines
end
-- get first line of a file
function helpers.first_line(path)
local file, first = io.open(path, "rb"), nil
if file then
first = file:read("*l")
file:close()
end
return first
end
-- get first non empty line from a file
function helpers.first_nonempty_line(path)
for line in io.lines(path) do
if #line then return line end
end
return nil
end
-- }}}
-- {{{ Timer maker
helpers.timer_table = {}
function helpers.newtimer(name, timeout, fun, nostart, stoppable)
if not name or #name == 0 then return end
name = (stoppable and name) or timeout
if not helpers.timer_table[name] then
helpers.timer_table[name] = timer({ timeout = timeout })
helpers.timer_table[name]:start()
end
helpers.timer_table[name]:connect_signal("timeout", fun)
if not nostart then
helpers.timer_table[name]:emit_signal("timeout")
end
return stoppable and helpers.timer_table[name]
end
-- }}}
-- {{{ Pipe operations
-- run a command and execute a function on its output (asynchronous pipe)
-- @param cmd the input command
-- @param callback function to execute on cmd output
-- @return cmd PID
function helpers.async(cmd, callback)
return spawn.easy_async(cmd,
function (stdout, _, _, exit_code)
callback(stdout, exit_code)
end)
end
-- like above, but call spawn.easy_async with a shell
function helpers.async_with_shell(cmd, callback)
return spawn.easy_async_with_shell(cmd,
function (stdout, _, _, exit_code)
callback(stdout, exit_code)
end)
end
-- run a command and execute a function on its output line by line
function helpers.line_callback(cmd, callback)
return spawn.with_line_callback(cmd, {
stdout = function (line)
callback(line)
end,
})
end
-- }}}
-- {{{ Network functions
-- fetch a http uri using lgi.Soup
function helpers.uri(uri, callback, error_handler)
error_handler = error_handler or gdebug.print_error
local ss = lgi.Soup.Session()
local msg = lgi.Soup.Message.new('GET', uri)
ss:send_and_read_async(msg, lgi.GLib.PRIORITY_DEFAULT, nil, function(_, resp, _)
local buf, err = ss:send_and_read_finish(resp)
if err then
error_handler(err)
elseif buf then
callback(buf:get_data())
end
end)
end
-- }}}
-- {{{ A map utility
helpers.map_table = {}
function helpers.set_map(element, value)
helpers.map_table[element] = value
end
function helpers.get_map(element)
return helpers.map_table[element]
end
-- }}}
-- {{{ Misc
-- check if an element exist on a table
function helpers.element_in_table(element, tbl)
for _, i in pairs(tbl) do
if i == element then
return true
end
end
return false
end
-- iterate over table of records sorted by keys
function helpers.spairs(t)
-- collect the keys
local keys = {}
for k in pairs(t) do keys[#keys+1] = k end
tsort(keys)
-- return the iterator function
local i = 0
return function()
i = i + 1
if keys[i] then
return keys[i], t[keys[i]]
end
end
end
-- create the partition of singletons of a given set
-- example: the trivial partition set of {a, b, c}, is {{a}, {b}, {c}}
function helpers.trivial_partition_set(set)
local ss = {}
for _,e in pairs(set) do
ss[#ss+1] = {e}
end
return ss
end
-- create the powerset of a given set
function helpers.powerset(s)
if not s then return {} end
local t = {{}}
for i = 1, #s do
for j = 1, #t do
t[#t+1] = {s[i],unpack(t[j])}
end
end
return t
end
-- }}}
return helpers