-
--[[
-
- Licensed under GNU General Public License v2
- * (c) 2013, Luke Bonham
-
---]]
+ Licensed under GNU General Public License v2
+ * (c) 2013, Luca CPZ
+--]]
+
+local spawn = require("awful.spawn")
+local timer = require("gears.timer")
local debug = require("debug")
local io = { lines = io.lines,
- open = io.open,
- popen = io.popen }
+ open = io.open }
+local pairs = pairs
local rawget = rawget
local table = { sort = table.sort }
-local easy_async = require("awful.spawn").easy_async
-local timer = require("gears.timer")
-local wibox = require("wibox")
-
-- Lain helper functions for internal use
-- lain.helpers
local helpers = {}
-- {{{ File operations
--- see if the file exists and is readable
-function helpers.file_exists(file)
- local f = io.open(file)
- if f then
- local s = f:read()
- f:close()
- f = s
- end
- return f ~= nil
-end
-
--- get all lines from a file, returns an empty
--- list/table if the file does not exist
-function helpers.lines_from(file)
- if not helpers.file_exists(file) then return {} end
- local lines = {}
- for line in io.lines(file) do
- lines[#lines + 1] = line
- end
- return lines
-end
-
--- match all lines from a file, returns an empty
--- list/table if the file or match does not exist
-function helpers.lines_match(regexp, file)
- local lines = {}
- for index,line in pairs(helpers.lines_from(file)) do
- if string.match(line, regexp) then
- lines[index] = line
- end
- end
- return lines
-end
-
--- get first line of a file, return nil if
--- the file does not exist
-function helpers.first_line(file)
- return helpers.lines_from(file)[1]
-end
-
--- get first non empty line from a file,
--- returns nil otherwise
-function helpers.first_nonempty_line(file)
- for k,v in pairs(helpers.lines_from(file)) do
- if #v then return v end
- end
- return nil
+-- 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
-- }}}
-- {{{ Pipe operations
--- return the full output of an input command (synchronous pipe)
--- @param cmd the input command
--- @return command output (string)
-function helpers.read_pipe(cmd)
- local f = io.popen(cmd)
- local output = f:read("*all")
- f:close()
- return output
-end
-
-- 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 easy_async(cmd,
+ return spawn.easy_async(cmd,
function (stdout, stderr, reason, exit_code)
- callback(stdout)
+ 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, stderr, reason, 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
+
-- }}}
-- {{{ A map utility
end
end
--- create a lain textbox
-function helpers.make_widget_textbox()
- local w = { widget = wibox.widget.textbox() }
- return setmetatable(w, { __index = w.widget })
+-- 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
+
+-- creates 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
-- }}}