From: daurnimator <quae@daurnimator.com>
Date: Tue, 22 Oct 2013 19:02:39 +0000 (-0400)
Subject: Add a `parse` module
X-Git-Url: https://git.madduck.net/etc/awesome.git/commitdiff_plain/30d7af10d208006ea09f32bd006c2cb2556a36ac

Add a `parse` module
---

diff --git a/luatz-scm-0.rockspec b/luatz-scm-0.rockspec
index 96709c7..167745a 100644
--- 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 1f223d1..2ad2ae8 100644
--- 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
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
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 )