renamed the API methods, updated the README

src/ezic.erl

@@ -1,7 +1,8 @@
 -module(ezic).
 -include("include/ezic.hrl").
 
--export([localtime/1, time2time/3]).
+-export([localtime/1, utc_to_local/2, utc_from_local/2, zone_convert/3]).
+
 -export([load/1, dev_start/0, test/0]).
 
 
@@ -10,36 +11,37 @@
 
 
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% API
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+
 localtime(TzName) ->
-    time(erlang:universaltime(), TzName).
+    utc_to_local(erlang:universaltime(), TzName).
 
 
-time(Datetime, TzName) ->
+utc_to_local(Datetime, TzName) ->
+    {ok, Zone, Rule}= current(Datetime, TzName),
+    SecDiff= offset(Zone, Rule),
+    date_add(Datetime, SecDiff).
+
     
-    Zones= ezic_db:zones(TzName),
-%    ?debug("All Zones: ~p", [Zones]),
-    CZone= ezic_zone:current(Datetime, Zones),
-%    ?debug("Current Zone: ~p", [CZone]),
-
-    RuleName= CZone#zone.rule,
-    Rules= ezic_db:rules(RuleName),
-%    ?debug("All Rules: ~p", [Rules]),
-    CRule= ezic_rule:current(Datetime, Rules),
-%    ?debug("Current Rule: ~p", [CRule]),
-
-    OffsetSec= ezic_zone:offset_sec(CZone),
-    DSTSec= ezic_rule:dst_sec(CRule),
-    
-    SecDiff= OffsetSec + DSTSec,
-    ?gs2dt(?dt2gs(Datetime) + SecDiff).
+utc_from_local(Datetime, TzName) ->
+    {ok, Zone, Rule}= current(Datetime, TzName),
+    SecDiff= offset(Zone, Rule),
+    date_subtract(Datetime, SecDiff).
     
 
-
-time2time(_DateTime, _FromTimeZone, _ToTimeZone) ->
-    void.
+zone_convert(Datetime, FromTimeZone, ToTimeZone) ->
+    UTC= utc_from_local(Datetime, FromTimeZone),
+    utc_to_local(UTC, ToTimeZone).
 
 
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% DEV API
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 
 
@@ -57,3 +59,40 @@ test() ->
 	      io:format("~s: ~p~n", [TZ, localtime(TZ)])
       end,
       ["Asia/Tokyo", "America/New_York", "America/Los_Angeles", "America/Jamaica", "Australia/Adelaide"]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% PRIVATE
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+current(Datetime, TzName) ->
+    Zones= ezic_db:zones(TzName),
+%    ?debug("All Zones: ~p", [Zones]),
+    CZone= ezic_zone:current(Datetime, Zones),
+%    ?debug("Current Zone: ~p", [CZone]),
+
+    RuleName= CZone#zone.rule,
+    Rules= ezic_db:rules(RuleName),
+%    ?debug("All Rules: ~p", [Rules]),
+    CRule= ezic_rule:current(Datetime, Rules),
+%    ?debug("Current Rule: ~p", [CRule]),
+    {ok, CZone, CRule}.
+    
+
+
+
+offset(Zone, Rule) ->
+    OffsetSec= ezic_zone:offset_sec(Zone),
+    DSTSec= ezic_rule:dst_sec(Rule),
+    OffsetSec + DSTSec.
+    
+
+
+date_add(Datetime, SecDiff) ->
+    ?gs2dt(?dt2gs(Datetime) + SecDiff).    
+
+date_subtract(Datetime, SecDiff) ->
+    ?gs2dt(?dt2gs(Datetime) - SecDiff).
+