luatz/timetable: Add __sub metamethod to allow subtraction of timetables. Reintroduce...

[etc/awesome.git] / luatz / timetable.lua

diff --git a/luatz/timetable.lua b/luatz/timetable.lua
index 3bb768911b627c9974f15f53b8d46c8b02080b4a..10af17018f90a9f14f5ef0c2ce72af9f9e367616 100644 (file)
--- a/luatz/timetable.lua
+++ b/luatz/timetable.lua
@@ -1,3 +1,4 @@
+local strftime = require "luatz.strftime".strftime
 local strformat = string.format
 local floor = math.floor
 local function idiv ( n , d )
@@ -143,7 +144,20 @@ function timetable_methods:rfc_3339 ( )
        return strformat ( "%04u-%02u-%02uT%02u:%02u:%06.3f" , self:unpack ( ) )
 end
 
-local timetable_mt = {
+function timetable_methods:strftime ( format_string )
+       return strftime ( format_string , self )
+end
+
+local timetable_mt
+
+local function coerce_arg ( t )
+       if getmetatable ( t ) == timetable_mt then
+               return t:timestamp ( )
+       end
+       return t
+end
+
+timetable_mt = {
        __index    = timetable_methods ;
        __tostring = timetable_methods.rfc_3339 ;
        __eq = function ( a , b )
@@ -152,6 +166,9 @@ local timetable_mt = {
        __lt = function ( a , b )
                return a:timestamp ( ) < b:timestamp ( )
        end ;
+       __sub = function ( a , b )
+               return coerce_arg ( a ) - coerce_arg ( b )
+       end ;
 }
 
 local function cast_timetable ( tm )