cpython/Lib/test/test_peg_generator/ast_dump.py

63 lines
2.6 KiB
Python

"""
Copy-parse of ast.dump, removing the `isinstance` checks. This is needed,
because testing pegen requires generating a C extension module, which contains
a copy of the symbols defined in Python-ast.c. Thus, the isinstance check would
always fail. We rely on string comparison of the base classes instead.
TODO: Remove the above-described hack.
"""
def ast_dump(node, annotate_fields=True, include_attributes=False, *, indent=None):
def _format(node, level=0):
if indent is not None:
level += 1
prefix = '\n' + indent * level
sep = ',\n' + indent * level
else:
prefix = ''
sep = ', '
if any(cls.__name__ == 'AST' for cls in node.__class__.__mro__):
cls = type(node)
args = []
allsimple = True
keywords = annotate_fields
for name in node._fields:
try:
value = getattr(node, name)
except AttributeError:
keywords = True
continue
if value is None and getattr(cls, name, ...) is None:
keywords = True
continue
value, simple = _format(value, level)
allsimple = allsimple and simple
if keywords:
args.append('%s=%s' % (name, value))
else:
args.append(value)
if include_attributes and node._attributes:
for name in node._attributes:
try:
value = getattr(node, name)
except AttributeError:
continue
if value is None and getattr(cls, name, ...) is None:
continue
value, simple = _format(value, level)
allsimple = allsimple and simple
args.append('%s=%s' % (name, value))
if allsimple and len(args) <= 3:
return '%s(%s)' % (node.__class__.__name__, ', '.join(args)), not args
return '%s(%s%s)' % (node.__class__.__name__, prefix, sep.join(args)), False
elif isinstance(node, list):
if not node:
return '[]', True
return '[%s%s]' % (prefix, sep.join(_format(x, level)[0] for x in node)), False
return repr(node), True
if all(cls.__name__ != 'AST' for cls in node.__class__.__mro__):
raise TypeError('expected AST, got %r' % node.__class__.__name__)
if indent is not None and not isinstance(indent, str):
indent = ' ' * indent
return _format(node)[0]