doc/index.md: Fix internal link

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

diff --git a/luatz/tzinfo.lua b/luatz/tzinfo.lua
index 11248adb34b11711372076447e2cfceaff49b4df..e37483f81a562828e28b392735b7c9f9c18339b4 100644 (file)
--- a/luatz/tzinfo.lua
+++ b/luatz/tzinfo.lua
@@ -1,35 +1,51 @@
 local gettime = require "luatz.gettime".gettime
+local timetable_mt = require "luatz.timetable".timetable_mt
+
+local function to_timestamp(o)
+       if type(o) == "number" then
+               return o
+       elseif getmetatable(o) == timetable_mt then
+               return o:timestamp()
+       end
+end
 
 local tz_info_methods = { }
 local tz_info_mt = {
-       __index = tz_info_methods ;
+       __name = "luatz.tz_info";
+       __index = tz_info_methods;
+}
+local tt_info_mt = {
+       __name = "luatz.tt_info";
+       __tostring = function(self)
+               return string.format("tt_info:%s=%d", self.abbr, self.gmtoff)
+       end;
 }
 
 -- Binary search
-local function _find_current ( tzinfo , target , i , j )
+local function find_current(tzinfo, target, i, j)
        if i >= j then return j end
 
-       local half = math.ceil ( (j+i) / 2 )
+       local half = math.ceil((j+i) / 2)
 
-       if target >= tzinfo [ half ].transition_time then
-               return _find_current ( tzinfo , target , half , j )
+       if target >= tzinfo[half].transition_time then
+               return find_current(tzinfo, target, half, j)
        else
-               return _find_current ( tzinfo , target , i , half-1 )
+               return find_current(tzinfo, target, i, half-1)
        end
 end
 
-local function find_current_local ( tzinfo , ts_local )
+local function find_current_local(tzinfo, ts_local)
        -- Find two best possibilities by searching back and forward a day (assumes transition is never by more than 24 hours)
-       local tz_first = _find_current ( tzinfo , ts_local-86400 , 0 , #tzinfo )
-       local tz_last  = _find_current ( tzinfo , ts_local+86400 , 0 , #tzinfo )
+       local tz_first = find_current(tzinfo, ts_local-86400, 0, #tzinfo)
+       local tz_last  = find_current(tzinfo, ts_local+86400, 0, #tzinfo)
 
        local n_candidates = tz_last - tz_first + 1
 
        if n_candidates == 1 then
                return tz_first
        elseif n_candidates == 2 then
-               local tz_first_ob = tzinfo [ tz_first ]
-               local tz_last_ob  = tzinfo [ tz_last ]
+               local tz_first_ob = tzinfo[tz_first]
+               local tz_last_ob  = tzinfo[tz_last]
 
                local first_gmtoffset = tz_first_ob.info.gmtoff
                local last_gmtoffset  = tz_last_ob .info.gmtoff
@@ -45,34 +61,37 @@ local function find_current_local ( tzinfo , ts_local )
                end
 
                -- If we get this far, the local time is ambiguous
-               return tz_first , tz_last
+               return tz_first, tz_last
        else
-               error ( "Too many transitions in a 2 day period" )
+               error("Too many transitions in a 2 day period")
        end
 end
 
-function tz_info_methods:find_current ( current )
-       return self [ _find_current ( self , current , 0 , #self ) ].info
+function tz_info_methods:find_current(current)
+       current = assert(to_timestamp(current), "invalid timestamp to :find_current")
+       return self[find_current(self, current, 0, #self)].info
 end
 
-function tz_info_methods:localise ( utc_ts )
-       utc_ts = utc_ts or gettime ( )
-       return utc_ts + self:find_current ( utc_ts ).gmtoff
+function tz_info_methods:localise(utc_ts)
+       utc_ts = utc_ts or gettime()
+       return utc_ts + self:find_current(utc_ts).gmtoff
 end
 tz_info_methods.localize = tz_info_methods.localise
 
-function tz_info_methods:utctime ( ts_local )
-       local tz1 , tz2 = find_current_local ( self , ts_local )
-       tz1 = self [ tz1 ].info
+function tz_info_methods:utctime(ts_local)
+       ts_local = assert(to_timestamp(ts_local), "invalid timestamp to :utctime")
+       local tz1, tz2 = find_current_local(self, ts_local)
+       tz1 = self[tz1].info
        if tz2 == nil then
                return ts_local - tz1.gmtoff
        else -- Local time is ambiguous
-               tz2 = self [ tz2 ].info
+               tz2 = self[tz2].info
 
-               return ts_local - tz2.gmtoff , ts_local - tz2.gmtoff
+               return ts_local - tz2.gmtoff, ts_local - tz2.gmtoff
        end
 end
 
 return {
-       tz_info_mt = tz_info_mt ;
+       tz_info_mt = tz_info_mt;
+       tt_info_mt = tt_info_mt;
 }