def visit_ListComp(self, node):
def makeattr(*args):
r = ast.Attribute(value=ast.Name(id='builtins',
ctx=ast.Load(),
annotation=None,
type_comment=None),
attr='map',
ctx=ast.Load())
r = ast.Call(r, list(args), [])
r = ast.Call(
ast.Attribute(ast.Name('builtins', ast.Load(), None, None),
'list', ast.Load()), [r], [])
return r
if isinstance(node.elt, ast.Constant) and len(node.generators) == 1:
gen = node.generators[0]
if not gen.ifs and isinstance(gen.iter, ast.Call):
try:
path = attr_to_path(gen.iter.func)[1]
range_path = 'pythonic', 'builtins', 'functor', 'range'
if path == range_path and len(gen.iter.args) == 1:
self.update = True
return ast.BinOp(
ast.List([node.elt], ast.Load()), ast.Mult(),
ast.Call(path_to_attr(('builtins', 'len')),
[gen.iter], []))
except TypeError:
pass
return self.visitComp(node, makeattr)
class SqrPattern(Pattern):
# X * X => X ** 2
pattern = ast.BinOp(left=Placeholder(0),
op=ast.Mult(),
right=Placeholder(0))
@staticmethod
def sub():
return ast.BinOp(left=Placeholder(0), op=ast.Pow(),
right=ast.Constant(2, None))
def expand_pow(self, node, n):
if n == 0:
return ast.Num(1)
elif n == 1:
return node
else:
node_square = self.replace(node)
node_pow = self.expand_pow(node_square, n >> 1)
if n & 1:
return ast.BinOp(node_pow, ast.Mult(), copy.deepcopy(node))
else:
return node_pow
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 isinstance(node.slice, ast.Index):
return node
if not isnum(node.slice.value):
return node
slice_ = node.value.slice
index = node.slice
node = node.value
node.slice = index
lower = slice_.lower or ast.Constant(0, None)
step = slice_.step or ast.Constant(1, None)
node.slice.value = ast.BinOp(lower,
ast.Add(),
ast.BinOp(index.value,
ast.Mult(),
step))
self.update = True
return node
keywords=[]),
lambda: ast.Call(func=ast.Attribute(value=ast.Name(
id='__builtin__', ctx=ast.Load(), annotation=None),
attr="xrange",
ctx=ast.Load()),
args=[
ast.BinOp(left=Placeholder(0),
op=ast.Sub(),
right=ast.Num(n=1)),
ast.Num(n=-1),
ast.Num(n=-1)
],
keywords=[])),
# X * X => X ** 2
(ast.BinOp(left=Placeholder(0), op=ast.Mult(), right=Placeholder(0)),
lambda: ast.BinOp(left=Placeholder(0), op=ast.Pow(), right=ast.Num(n=2))),
# a + "..." + b => "...".join((a, b))
(ast.BinOp(left=ast.BinOp(left=Placeholder(0),
op=ast.Add(),
right=ast.Str(Placeholder(1))),
op=ast.Add(),
right=Placeholder(2)),
lambda: ast.Call(func=ast.Attribute(
ast.Attribute(ast.Name('__builtin__', ast.Load(), None), 'str',
ast.Load()), 'join', ast.Load()),
args=[
ast.Str(Placeholder(1)),
ast.Tuple([Placeholder(0),
Placeholder(2)], ast.Load())
