Add a `parse` module

diff --git a/luatz-scm-0.rockspec b/luatz-scm-0.rockspec
index 96709c75f5844f13729710b8a77ad1b69eb357a6..167745ac44a6cadf04878a4f3ea31d7044dca612 100644 (file)
--- a/luatz-scm-0.rockspec
+++ b/luatz-scm-0.rockspec
@@ -24,6 +24,7 @@ build = {
        modules = {
                ["luatz.init"]      = "luatz/init.lua" ;
                ["luatz.gettime"]   = "luatz/gettime.lua" ;
+               ["luatz.parse"]     = "luatz/parse.lua" ;
                ["luatz.timetable"] = "luatz/timetable.lua" ;
                ["luatz.tzcache"]   = "luatz/tzcache.lua" ;
                ["luatz.tzfile"]    = "luatz/tzfile.lua" ;

diff --git a/luatz/init.lua b/luatz/init.lua
index 1f223d10c9022916ebcc4d059c8a049de848f8af..2ad2ae8ecab2d49313a77f71e513b2374656fed5 100644 (file)
--- a/luatz/init.lua
+++ b/luatz/init.lua
@@ -8,5 +8,6 @@ return {
        get_tz    = get_tz ;
        gettime   = require "luatz.gettime".gettime ;
        gettimein = gettimein ;
+       parse     = require "luatz.parse" ;
        timetable = require "luatz.timetable" ;
 }

diff --git a/luatz/parse.lua b/luatz/parse.lua
new file mode 100644 (file)
index 0000000..2c5f8d3
--- /dev/null
+++ b/luatz/parse.lua
@@ -0,0 +1,40 @@
+local new_timetable = require "luatz.timetable".new
+
+--- Parse an RFC 3339 datetime at the given position
+-- Returns a time table and the `tz_offset`
+-- Return value is not normalised (this preserves a leap second)
+-- If the timestamp is only partial (i.e. missing "Z" or time offset) then `tz_offset` will be nil
+-- TODO: Validate components are within their boundarys (e.g. 1 <= month <= 12)
+local function rfc_3339 ( str , init )
+       local year , month , day , hour , min , sec , patt_end = str:match ( "^(%d%d%d%d)%-(%d%d)%-(%d%d)[Tt](%d%d%.?%d*):(%d%d):(%d%d)()" , init )
+       if not year then
+               error ( "Invalid RFC 3339 timestamp" )
+       end
+       year  = tonumber ( year )
+       month = tonumber ( month )
+       day   = tonumber ( day )
+       hour  = tonumber ( hour )
+       min   = tonumber ( min )
+       sec   = tonumber ( sec )
+
+       local tt = new_timetable ( year , month , day , hour , min , sec )
+
+       local tz_offset
+       if str:match ("^[Zz]" , patt_end ) then
+               tz_offset = 0
+       else
+               local hour_offset , min_offset = str:match ( "^([+-]%d%d):(%d%d)" , patt_end )
+               if hour_offset then
+                       tz_offset = tonumber ( hour_offset )*60 + tonumber ( min_offset )
+               else
+                       -- Invalid RFC 3339 timestamp offset (should be Z or (+/-)hour:min
+                       -- tz_offset will be nil
+               end
+       end
+
+       return tt , tz_offset
+end
+
+return {
+       rfc_3339 = rfc_3339 ;
+}

diff --git a/spec/parse_spec.lua b/spec/parse_spec.lua
new file mode 100644 (file)
index 0000000..f66015a
--- /dev/null
+++ b/spec/parse_spec.lua
@@ -0,0 +1,14 @@
+describe ( "Time parsing library" , function ( )
+       local timetable = require "luatz.timetable"
+       local parse = require "luatz.parse"
+
+       it ( "RFC 3339 Parsing" , function ( )
+               assert.same ( timetable.new(2013,10,22,14,17,02) , (parse.rfc_3339 "2013-10-22T14:17:02Z") )
+
+               -- Numeric offsets accepted
+               assert.same ( { timetable.new(2013,10,22,14,17,02) , 10*60 } , { parse.rfc_3339 "2013-10-22T14:17:02+10:00" } )
+
+               -- Missing offsets parse
+               assert.same ( timetable.new(2013,10,22,14,17,02) , (parse.rfc_3339 "2013-10-22T14:17:02") )
+       end )
+end )