Merge pull request #416 from BarbUk/fix/tp_smapi

[etc/awesome.git] / helpers.lua

diff --git a/helpers.lua b/helpers.lua
index 4ece329a6dc886f4e106ceb2711d1589a0a99334..4d75f7b6067f7eb9d5430eeac9e5cedbd785e06c 100644 (file)
--- a/helpers.lua
+++ b/helpers.lua
@@ -1,19 +1,18 @@
-
 --[[
-                                                  
-     Licensed under GNU General Public License v2 
-      * (c) 2013, Luke Bonham                     
-                                                  
---]]
 
-local debug  = require("debug")
+     Licensed under GNU General Public License v2
+      * (c) 2013, Luca CPZ
+
+--]]
 
-local capi   = { timer = timer }
-local io     = { open  = io.open,
-                 lines = io.lines,
-                 popen = io.popen }
-local rawget = rawget
-local table  = { sort   = table.sort }
+local spawn      = require("awful.spawn")
+local timer      = require("gears.timer")
+local debug      = require("debug")
+local io         = { lines = io.lines,
+                     open  = io.open }
+local pairs      = pairs
+local rawget     = rawget
+local table      = { sort  = table.sort }
 
 -- Lain helper functions for internal use
 -- lain.helpers
@@ -34,41 +33,49 @@ end
 
 -- {{{ 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
+-- 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 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
-  lines = {}
-  for line in io.lines(file) do
-    lines[#lines + 1] = line
-  end
-  return lines
+-- 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 first line of a file, return nil if
--- the file does not exist
-function helpers.first_line(file)
-    return helpers.lines_from(file)[1]
+-- 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 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
+-- 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
 
 -- }}}
@@ -77,25 +84,50 @@ end
 
 helpers.timer_table = {}
 
-function helpers.newtimer(name, timeout, fun, nostart)
-    helpers.timer_table[name] = capi.timer({ timeout = timeout })
+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)
-    helpers.timer_table[name]:start()
     if not nostart then
         helpers.timer_table[name]:emit_signal("timeout")
     end
+    return stoppable and helpers.timer_table[name]
 end
 
 -- }}}
 
 -- {{{ Pipe operations
 
--- read the full output of a pipe (command)
-function helpers.read_pipe(cmd)
-   local f = assert(io.popen(cmd))
-   local output = f:read("*all")
-   f:close()
-   return output
+-- 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, stderr, reason, 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, 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
 
 -- }}}
@@ -114,7 +146,19 @@ end
 
 -- }}}
 
---{{{ Iterate over table of records sorted by keys
+-- {{{ 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 = {}
@@ -131,6 +175,29 @@ function helpers.spairs(t)
         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
+
+-- 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
+
+-- }}}
 
 return helpers