def visit_UnaryOp(self, node):
""" Update range with given unary operation.
>>> import ast
>>> from pythran import passmanager, backend
>>> node = ast.parse('''
... def foo():
... a = 2
... c = -a
... d = ~a
... f = +a
... e = not a''')
>>> pm = passmanager.PassManager("test")
>>> res = pm.gather(RangeValues, node)
>>> res['f']
Range(low=2, high=2)
>>> res['c']
Range(low=-2, high=-2)
>>> res['d']
Range(low=-3, high=-3)
>>> res['e']
Range(low=0, high=1)
"""
res = self.visit(node.operand)
if isinstance(node.op, ast.Not):
return Range(0, 1)
elif (isinstance(node.op, ast.Invert) and isinstance(res.high, int)
and isinstance(res.low, int)):
return Range(~res.high, ~res.low)
elif isinstance(node.op, ast.UAdd):
return res
elif isinstance(node.op, ast.USub):
return Range(-res.high, -res.low)
else:
return UNKNOWN_RANGE
def visit_Compare(node):
""" Boolean are possible index.
>>> import ast
>>> from pythran import passmanager, backend
>>> node = ast.parse('''
... def foo():
... a = 2 or 3
... b = 4 or 5
... c = a < b''')
>>> pm = passmanager.PassManager("test")
>>> res = pm.gather(RangeValues, node)
>>> res['c']
Range(low=0, high=1)
"""
return Range(0, 1)
def visit_BoolOp(self, node):
""" Merge right and left operands ranges.
TODO : We could exclude some operand with this range information...
>>> import ast
>>> from pythran import passmanager, backend
>>> node = ast.parse('''
... def foo():
... a = 2
... c = 3
... d = a or c''')
>>> pm = passmanager.PassManager("test")
>>> res = pm.gather(RangeValues, node)
>>> res['d']
Range(low=2, high=3)
"""
res = zip(*map(self.visit, node.values))
return Range(min(res[0]), max(res[1]))
def visit_IfExp(self, node):
""" Use worst case for both possible values.
>>> import ast
>>> from pythran import passmanager, backend
>>> node = ast.parse('''
... def foo():
... a = 2 or 3
... b = 4 or 5
... c = a if a else b''')
>>> pm = passmanager.PassManager("test")
>>> res = pm.gather(RangeValues, node)
>>> res['c']
Range(low=2, high=5)
"""
self.visit(node.test)
body_res = self.visit(node.body)
orelse_res = self.visit(node.orelse)
return Range(min(orelse_res.low, body_res.low),
max(orelse_res.high, body_res.high))
def visit_Num(node):
""" Handle literals integers values. """
if isinstance(node.n, int):
return Range(node.n, node.n)
else:
return UNKNOWN_RANGE