Added support for dates

git-svn-id: http://galileo.dmi.unict.it/svn/relational/trunk@35 014f5005-505e-4b48-8d0a-63407b615a7c

CHANGELOG

@@ -27,3 +27,4 @@
 
 0.5
 - Added support for float numbers
+- Added support for dates

relation.py

@@ -16,7 +16,7 @@
 # 
 # author Salvo "LtWorf" Tomaselli <tiposchi@tiscali.it>
 
-import rtypes
+from rtypes import *
 
 class relation (object):
 	'''This objects defines a relation (as a group of consistent tuples) and operations
@@ -78,8 +78,10 @@ class relation (object):
 			for j in range(len(self.header.attributes)):
 				if i[j].isdigit():
 					attributes[self.header.attributes[j]]=int(i[j])
-				elif rtypes.rstring(i[j]).isFloat():
+				elif rstring(i[j]).isFloat():
 					attributes[self.header.attributes[j]]=float(i[j])
+				elif isDate(i[j]):
+					attributes[self.header.attributes[j]]=rdate(i[j])
 				else:
 					attributes[self.header.attributes[j]]=i[j]
 				

rtypes.py

@@ -17,12 +17,83 @@
 # author Salvo "LtWorf" Tomaselli <tiposchi@tiscali.it>
 
 '''Custom types for relational algebra'''
+
+import datetime
+
 class rstring (str):
 	'''String subclass with some custom methods'''
 	def isFloat(self):
 		'''True if the string is a float number, false otherwise'''
-		lst=['0','1','2','3','4','5','6','7','8','9','.']
+		lst=('0','1','2','3','4','5','6','7','8','9','.')
 		for i in self:
 			if i not in lst:
 				return False;
 		return True;
+
+class rdate (object):
+	'''Represents a date'''
+	def __init__(self,date):
+		sep=('-','/','\\')
+		splitter=None
+		for i in sep:
+			if i in date:
+				splitter=i
+				break;
+		elems=date.split(splitter)
+		
+		year=int(elems[0])
+		month=int(elems[1])
+		day=int(elems[2])
+		
+		self.intdate=datetime.date(year,month,day)
+		self.day= self.intdate.day
+		self.month=self.intdate.month
+		self.weekday=self.intdate.weekday()
+		self.year=self.intdate.year
+		
+	def __str__(self):
+		return self.intdate.__str__()
+	def __add__(self,days):
+		res=self.intdate+datetime.timedelta(days)
+		return rdate(res.__str__())
+	
+	def __eq__(self,other):
+		return self.intdate==other.intdate
+	def __ge__(self,other):
+		return self.intdate>=other.intdate
+	def __gt__ (self,other):
+		return self.intdate>other.intdate
+	def __le__ (self,other):
+		return self.intdate<=other.intdate
+	def __lt__ (self,other):
+		return self.intdate<other.intdate
+	def __ne__(self,other):
+		return self.intdate!=other.intdate
+	def __sub__ (self,other):
+		return (self.intdate-other.intdate).days
+def isDate(date):
+	sep=('-','/','\\')
+	splitter=None
+	for i in sep:
+		if i in date:
+			splitter=i
+			break;
+	elems=date.split(splitter)
+	if len(elems)!=3:
+		return False #Wrong number of elements
+	year=elems[0]
+	month=elems[1]
+	day=elems[2]
+	if not (year.isdigit() and month.isdigit() and day.isdigit()):
+		return False
+	year=int(year)
+	month=int(month)
+	day=int(day)
+	
+	if year<datetime.MINYEAR or year>datetime.MAXYEAR:
+		return False
+	if month<1 or month>12:
+		return False
+	if day<1 or day >31:
+		return False
+	return True

samples/dates.tlb

@@ -0,0 +1,6 @@
+date
+2008-12-12
+2007-08-12
+1985-05-09
+1988-4-21
+1992-7-27

samples/people.tlb

@@ -1,5 +1,5 @@
 id name chief age
-0 jack 0 22.1
+0 jack 0 22
 1 carl 0 20
 2 john 1 30
 3 dean 1 33