def visit_For(self, node):
"""restricted, for now, to range as iterator with long-type args"""
if isinstance(node, ast.For) and \
isinstance(node.iter, ast.Call) and \
isinstance(node.iter.func, ast.Name) and \
node.iter.func.id == 'range':
Range = node.iter
nArgs = len(Range.args)
if nArgs == 1:
stop = self.visit(Range.args[0])
start, step = Constant(0), Constant(1)
elif nArgs == 2:
start, stop = map(self.visit, Range.args)
step = Constant(1)
elif nArgs == 3:
start, stop, step = map(self.visit, Range.args)
else:
raise Exception("Cannot convert a for...range with %d args." % nArgs)
# TODO allow any expressions castable to Long type
assert isinstance(stop.get_type(), c_long), "Can only convert range's with stop values of Long type."
assert isinstance(start.get_type(), c_long), "Can only convert range's with start values of Long type."
assert isinstance(step.get_type(), c_long), "Can only convert range's with step values of Long type."
target = SymbolRef(node.target.id, c_long())
for_loop = For(
Assign(target, start),
Lt(target.copy(), stop),
AddAssign(target.copy(), step),
[self.visit(stmt) for stmt in node.body],
)
return for_loop
node.body = list(map(self.visit, node.body))
return node
def visit_AugAssign(self, node):
op = type(node.op)
target = self.visit(node.target)
value = self.visit(node.value)
if op is ast.Add:
return AddAssign(target, value)
elif op is ast.Sub:
return SubAssign(target, value)
elif op is ast.Mult:
return MulAssign(target, value)
elif op is ast.Div:
return DivAssign(target, value)
# TODO: Error?
return node
def visit_For(self, node):
"""restricted, for now, to range as iterator with long-type args"""
if isinstance(node, ast.For) and \
isinstance(node.iter, ast.Call) and \
isinstance(node.iter.func, ast.Name) and \
node.iter.func.id in ('range', 'xrange'):
Range = node.iter
nArgs = len(Range.args)
if nArgs == 1:
stop = self.visit(Range.args[0])
start, step = Constant(0), Constant(1)
elif nArgs == 2:
start, stop = map(self.visit, Range.args)
step = Constant(1)
elif nArgs == 3:
start, stop, step = map(self.visit, Range.args)
else:
raise Exception("Cannot convert a for...range with %d args." %
nArgs)
# check no-op conditions.
if all(isinstance(item, Constant) for item in (start, stop, step)):
if step.value == 0:
raise ValueError("range() step argument must not be zero")
elif start.value == stop.value or \
(start.value < stop.value and step.value < 0) or \
(start.value > stop.value and step.value > 0):
return None
if not all(
isinstance(item, CtreeNode)
for item in (start, stop, step)):
node.body = list(map(self.visit, node.body))
return node
# TODO allow any expressions castable to Long type
target_types = [c_long]
for el in (stop, start, step):
# typed item to try and guess type off of. Imperfect right now.
if hasattr(el, 'get_type'):
# TODO take the proper class instead of the last; if start,
# end are doubles, but step is long, target is double
t = el.get_type()
assert any(
isinstance(t, klass)
for klass in [c_byte, c_int, c_long, c_short]
), "Can only convert ranges with integer/long \
start/stop/step values"
target_types.append(type(t))
target_type = get_common_ctype(target_types)()
target = SymbolRef(node.target.id, target_type)
op = Lt
if hasattr(start, 'value') and hasattr(stop, 'value') and \
start.value > stop.value:
op = Gt
for_loop = For(
Assign(target, start),
op(target.copy(), stop),
AddAssign(target.copy(), step),
[self.visit(stmt) for stmt in node.body],
)
return for_loop
node.body = list(map(self.visit, node.body))
return node