karanlyons/method_missing.py

## method_missing.py
import dis
import inspect


class MethodMissingMixin:
	def __getattr__(self, attr):
		if hasattr(getattr(self, '__methodmissing__', None), '__call__'):
			parent_frame = inspect.currentframe().f_back
			instructions = dis.get_instructions(parent_frame.f_code)

			for instruction in instructions:
				if (
					instruction.offset >= parent_frame.f_lasti and
					instruction.opname == 'LOAD_ATTR' and
					instruction.argval == attr
				):
					stack_offset = 0
					break

			for instruction in instructions:
				stack_offset += dis.stack_effect(instruction.opcode, instruction.arg)

				if stack_offset == 0 and instruction.opname.startswith('CALL_FUNCTION'):
					return lambda *args, **kwargs: self.__methodmissing__(attr, *args, **kwargs)

				elif stack_offset < 0:
					break

			return self.__methodmissing__(attr)

		return super().__getattr__(attr)

## usage.py
from method_missing import MethodMissingMixin


class XML(MethodMissingMixin, object):
	def __init__(self, stack=None):
		self._stack = stack if stack is not None else []

	def __methodmissing__(self, name, *args, **kwargs):
		return XML(self._stack + [(name, args, kwargs)])

	def _build_tree(self, i_start=0):
		tree = []

		for i, (name, children, attrs) in enumerate(self._stack, i_start):
			tree.append('%s<%s%s%s>' % (
				'\t' * i, name,
				' ' if attrs else '',
				' '.join('%s=%r' % (key, value) for key, value in attrs.items()))
			)

			for child in children:
				if isinstance(child, XML):
					tree.extend(child._build_tree(i + 1))

				else:
					tree.append('%s%s' % ('\t' * (i + 1), child))

		for j, (name, children, attrs) in enumerate(reversed(self._stack)):
			tree.append('%s</%s>' % ('\t' * (i - j), name))

		return tree

	def __str__(self, i_start=0):
		return '\n'.join(self._build_tree())


x = XML()

print(x.html(
	x.head,
	x.body(
		x.p(
			'What hath God wrought.',
			id='abomination',
		)
	),
	lang='en'
))

# Output:
#	<html lang='en'>
#		<head>
#		</head>
#		<body>
#			<p id='abomination'>
#				What hath God wrought.
#			</p>
#		</body>
#	</html>
	import dis
	import inspect


	class MethodMissingMixin:
	def __getattr__(self, attr):
	if hasattr(getattr(self, '__methodmissing__', None), '__call__'):
	parent_frame = inspect.currentframe().f_back
	instructions = dis.get_instructions(parent_frame.f_code)

	for instruction in instructions:
	if (
	instruction.offset >= parent_frame.f_lasti and
	instruction.opname == 'LOAD_ATTR' and
	instruction.argval == attr
	):
	stack_offset = 0
	break

	for instruction in instructions:
	stack_offset += dis.stack_effect(instruction.opcode, instruction.arg)

	if stack_offset == 0 and instruction.opname.startswith('CALL_FUNCTION'):
	return lambda args, kwargs: self.__methodmissing__(attr, args, **kwargs)

	elif stack_offset < 0:
	break

	return self.__methodmissing__(attr)

	return super().__getattr__(attr)
	from method_missing import MethodMissingMixin


	class XML(MethodMissingMixin, object):
	def __init__(self, stack=None):
	self._stack = stack if stack is not None else []

	def __methodmissing__(self, name, args, *kwargs):
	return XML(self._stack + [(name, args, kwargs)])

	def _build_tree(self, i_start=0):
	tree = []

	for i, (name, children, attrs) in enumerate(self._stack, i_start):
	tree.append('%s<%s%s%s>' % (
	'\t' * i, name,
	' ' if attrs else '',
	' '.join('%s=%r' % (key, value) for key, value in attrs.items()))
	)

	for child in children:
	if isinstance(child, XML):
	tree.extend(child._build_tree(i + 1))

	else:
	tree.append('%s%s' % ('\t' * (i + 1), child))

	for j, (name, children, attrs) in enumerate(reversed(self._stack)):
	tree.append('%s</%s>' % ('\t' * (i - j), name))

	return tree

	def __str__(self, i_start=0):
	return '\n'.join(self._build_tree())


	x = XML()

	print(x.html(
	x.head,
	x.body(
	x.p(
	'What hath God wrought.',
	id='abomination',
	)
	),
	lang='en'
	))

	# Output:
	# <html lang='en'>
	# <head>
	# </head>
	# <body>
	# <p id='abomination'>
	# What hath God wrought.
	# </p>
	# </body>
	# </html>