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- Can parse expressions with division operator

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git-svn-id: http://galileo.dmi.unict.it/svn/relational/trunk@239 014f5005-505e-4b48-8d0a-63407b615a7c
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LtWorf 2010-07-02 13:58:16 +00:00
parent 215386350d
commit 814594e825
1 changed files with 6 additions and 3 deletions
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9
relational/parser.py
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@ -22,10 +22,10 @@
RELATION=0 RELATION=0
UNARY=1 UNARY=1
BINARY=2 BINARY=2
b_operators=('*','-','ᑌ','ᑎ','ᐅᐊ','ᐅLEFTᐊ','ᐅRIGHTᐊ','ᐅFULLᐊ') b_operators=('*','-','ᑌ','ᑎ','÷','ᐅᐊ','ᐅLEFTᐊ','ᐅRIGHTᐊ','ᐅFULLᐊ')
u_operators=('π','σ','ρ') u_operators=('π','σ','ρ')
op_functions={'*':'product','-':'difference','ᑌ':'union','ᑎ':'intersection','ᐅᐊ':'join','ᐅLEFTᐊ':'outer_left','ᐅRIGHTᐊ':'outer_right','ᐅFULLᐊ':'outer','π':'projection','σ':'selection','ρ':'rename'} op_functions={'*':'product','-':'difference','ᑌ':'union','ᑎ':'intersection','÷':'division','ᐅᐊ':'join','ᐅLEFTᐊ':'outer_left','ᐅRIGHTᐊ':'outer_right','ᐅFULLᐊ':'outer','π':'projection','σ':'selection','ρ':'rename'}
class node (object): class node (object):
'''This class is a node of a relational expression. Leaves are relations and internal nodes are operations. '''This class is a node of a relational expression. Leaves are relations and internal nodes are operations.
@ -257,7 +257,10 @@ def tokenize(expression):
elif expression.startswith("ᑎ") or expression.startswith("ᑌ"): #Binary short 3 bytes elif expression.startswith("ᑎ") or expression.startswith("ᑌ"): #Binary short 3 bytes
items.append(expression[0:3]) #Adding operator in the top of the list items.append(expression[0:3]) #Adding operator in the top of the list
expression=expression[3:].strip() #Removing operator from the expression expression=expression[3:].strip() #Removing operator from the expression
state=4
elif expression.startswith("÷"): #Binary short 2 bytes
items.append(expression[0:2]) #Adding operator in the top of the list
expression=expression[2:].strip() #Removing operator from the expression
state=4 state=4
elif expression.startswith("ᐅ"): #Binary long elif expression.startswith("ᐅ"): #Binary long
i=expression.find("ᐊ") i=expression.find("ᐊ")