def fold_mult_right(self, node):
if not isinstance(node.right, (ast.List, ast.Tuple)):
return False
if not isnum(node.left):
return False
# FIXME: remove that check once we have a proper type inference engine
if not isintegral(node.left):
raise PythranSyntaxError("Multiplying a sequence by a float", node)
return isinstance(node.op, ast.Mult)
def visit_Subscript(self, node):
"""
>>> import gast as ast
>>> from pythran import passmanager, backend
>>> pm = passmanager.PassManager("test")
>>> node = ast.parse("def foo(a): a[1:][3]")
>>> _, node = pm.apply(PartialConstantFolding, node)
>>> _, node = pm.apply(ConstantFolding, node)
>>> print(pm.dump(backend.Python, node))
def foo(a):
a[4]
>>> node = ast.parse("def foo(a): a[::2][3]")
>>> _, node = pm.apply(PartialConstantFolding, node)
>>> _, node = pm.apply(ConstantFolding, node)
>>> print(pm.dump(backend.Python, node))
def foo(a):
a[6]
>>> node = ast.parse("def foo(a): a[-4:][5]")
>>> _, node = pm.apply(PartialConstantFolding, node)
>>> _, node = pm.apply(ConstantFolding, node)
>>> print(pm.dump(backend.Python, node))
def foo(a):
a[1]
"""
self.generic_visit(node)
if not isinstance(node.value, ast.Subscript):
return node
if not isinstance(node.value.slice, ast.Slice):
return node
if not isintegral(node.slice):
return node
slice_ = node.value.slice
index = node.slice
node = node.value
lower = slice_.lower or ast.Constant(0, None)
step = slice_.step or ast.Constant(1, None)
node.slice = ast.BinOp(lower,
ast.Add(),
ast.BinOp(index,
ast.Mult(),
step))
self.update = True
return node