def convertNumericalComparison(name, gt, value, nbits=32):
"""Given a numerical comparison in base-10, this function will construct a
boolean formula representing the comparison in base-2.
Unless specified the default word size for integers will be 32.
@type name: str
@param name: The name of attribute being compared.
@type gt: bool
@param gt: True if greater than else False
@type value: int
@param value: The value being compared against the attribute.
@type nbits: int
@param nbits: The word size used to represent integers.
@rtype: str
@return: Returns a string containing the comparison in Base-2.
"""
# Find right most used bit
i = 0
while bool(1 << i & value) if gt else not bool(1 << i & value):
i += 1
p = leaf_policy(bitmarker(name, nbits, i, int(gt)))
# For each remaining used bit in string
for i in range(i+1, nbits):
if gt:
# if > then AND if bit is used else OR
node_type = 2 if bool(1 << i & value) else 1
else:
# if < then OR if bit is used else AND
node_type = 1 if bool(1 << i & value) else 2
p = kof2_policy(node_type, p,
leaf_policy(bitmarker(name, nbits, i, int(gt))))
return policyToString(p)
def convertNumericalComparison(name, gt, value, nbits=32):
"""Given a numerical comparison in base-10, this function will construct a
boolean formula representing the comparison in base-2.
Unless specified the default word size for integers will be 32.
@type name: str
@param name: The name of attribute being compared.
@type gt: bool
@param gt: True if greater than else False
@type value: int
@param value: The value being compared against the attribute.
@type nbits: int
@param nbits: The word size used to represent integers.
@rtype: str
@return: Returns a string containing the comparison in Base-2.
"""
# Find right most used bit
i = 0
while bool(1 << i & value) if gt else not bool(1 << i & value):
i += 1
p = leaf_policy(bitmarker(name, nbits, i, int(gt)))
# For each remaining used bit in string
for i in range(i + 1, nbits):
if gt:
# if > then AND if bit is used else OR
node_type = 2 if bool(1 << i & value) else 1
else:
# if < then OR if bit is used else AND
node_type = 1 if bool(1 << i & value) else 2
p = kof2_policy(node_type, p,
leaf_policy(bitmarker(name, nbits, i, int(gt))))
return policyToString(p)
def constructNumericalAttribute(name, value, nbits):
"""Transforms an attribute assignment into the base-2 bit masking
representation.
@type name: str
@param name: The name of the attribute.
@type value: int
@param value: The value being assigned to the attribute.
@type nbits: int
@param nbits: The word size used to represent integers.
@rtype: List[str]
@return: A list of bit markers representing the value of each bit
in the base-2 representaiton.
"""
attributes = [];
for i in range(0,nbits):
bit = int(bool(1 << i & value))
attributes.append(bitmarker(name,nbits,i,bit))
return attributes
def constructNumericalAttribute(name, value, nbits):
"""Transforms an attribute assignment into the base-2 bit masking
representation.
@type name: str
@param name: The name of the attribute.
@type value: int
@param value: The value being assigned to the attribute.
@type nbits: int
@param nbits: The word size used to represent integers.
@rtype: List[str]
@return: A list of bit markers representing the value of each bit
in the base-2 representaiton.
"""
attributes = []
for i in range(0, nbits):
bit = int(bool(1 << i & value))
attributes.append(bitmarker(name, nbits, i, bit))
return attributes
