def transform(self, x):
if isinstance(x, Node):
method = 'transform' + x.__class__.__name__
if hasattr(self, method):
return getattr(self, method)(x)
else:
return self._transform_children(x)
elif is_sequence(x) and not isinstance(x, basestring):
return x.__class__(map(self.transform, x))
else:
return deepcopy(x)
def walk(x, visitor, walker=None, verbose=None):
"Wrap compiler.walk to handle 'None' and sequences."
# (Nodes are iterable and strings cause infinite regress)
if x is None:
return visitor
elif isinstance(x, Node):
return compiler.walk(x, visitor, walker, verbose)
elif is_sequence(x) and not isinstance(x, basestring):
for n in x:
visitor = walk(n, visitor, walker, verbose)
return visitor
else:
raise ValueError(x)
def __init__(self, x=(), file=None, **kw):
super(Block, self).__init__(**kw)
self.on_trait_change(self._structure_changed, 'sub_blocks')
self.on_trait_change(self._structure_changed, 'sub_blocks_items')
self.on_trait_change(self._structure_changed, 'ast')
# Interpret arguments:
is_file_object = lambda o: hasattr(o, 'read') and hasattr(o, 'name')
# 'file' -> 'x'
if file is not None:
# Turn 'file' into a file object and move to 'x'
if isinstance(file, basestring):
file = open(file)
elif not is_file_object(file):
raise ValueError("Expected 'file' to be a file or string, "
"got %r" % f)
x = file
# 'x': file object -> string
saved_filename = None
if is_file_object(x):
self.filename = x.name
saved_filename = self.filename
x = x.read()
# 'x' -> 'self.ast' or 'self.sub_blocks'
if isinstance(x, basestring):
# (BlockTransformer handles things like 'import *')
self.ast = parse(x, mode='exec', transformer=BlockTransformer())
elif isinstance(x, Node):
self.ast = x
elif is_sequence(x):
self.sub_blocks = map(to_block, x)
else:
raise ValueError('Expecting string, Node, or sequence. Got %r' % x)
# We really want to keep the filename for "pristine" blocks, and
# _structure_changed nukes it most times
self.filename = saved_filename
def is_fork(x, leaves=()):
'Test whether a tree is a fork (instead of a leaf).'
return is_sequence(x) and not isinstance(x, leaves)
def is_fork(x, leaves=()):
'Test whether a tree is a fork (instead of a leaf).'
return is_sequence(x) and not isinstance(x, leaves)
