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())