Mini Shell

class Doc:  # base class
    def __mod__(self, other):
        other = self.mod.getdoc(other)
        return self.mapchildren(lambda x: x % other)

    def __rmod__(self, other):
        return self.mod.getdoc(other) % self

    def __str__(self):
        return self.getstr()

    def __eq__(self, other):
        if not isinstance(other, self.__class__):
            return 0

        return str(self) == str(other)

    def __hash__(self):
        return hash(str(self))

    def shortest(self):
        return self.mapchildren(lambda x: x.shortest())


class Anon(Doc):
    def __init__(self, mod, obj):
        self.mod = mod
        self.obj = obj

    def getstr(self):
        return repr(self.obj)

    def mapchildren(self, f):
        return self


class Source(Doc):
    def __init__(self, mod, text):
        self.mod = mod
        self.text = text

    def getstr(self):
        return self.text

    def mapchildren(self, f):
        return self


class Attribute(Doc):
    def __init__(self, mod, obj, name):
        self.mod = mod
        self.obj = obj
        self.name = name

    def __mod__(self, other):
        if self.obj is other:
            return self.mod.rootattribute(other, self.name)
        return self.mapchildren(lambda x: x % other)

    def getstr(self):
        return '%s.%s' % (self.obj.getstr(), self.name)

    def mapchildren(self, f):
        return self.__class__(self.mod, f(self.obj), self.name)


class RootAttribute(Doc):
    def __init__(self, mod, obj, name):
        self.mod = mod
        self.obj = obj
        self.name = name

    def getstr(self):
        return '%s' % (self.name,)

    def mapchildren(self, f):
        return self


class BinaryOp(Doc):
    table = {
        'and': '&',
        'or': '|',
        'sub': '-',
        'mul': '*',
        'pow': '**',
        'lshift': '<<',
        'rshift': '>>',
    }

    def __init__(self, mod, op, a, b):
        self.mod = mod
        self.op = op
        self.a = a
        self.b = b

    def getstr(self):
        return '%s %s %s' % (self.a.getstr(),
                             self.table[self.op],
                             self.b.getstr())

    def mapchildren(self, f):
        return self.__class__(self.mod, self.op, f(self.a), f(self.b))


class UnaryOp(Doc):
    table = {
        'invert': '~',
        'neg': '-',
        'pos': '+',
    }

    def __init__(self, mod, op, a):
        self.mod = mod
        self.op = op
        self.a = a

    def getstr(self):
        return '%s %s' % (self.table[self.op], self.a.getstr())

    def mapchildren(self, f):
        return self.__class__(self.mod, self.op, f(self.a))


class CallFunc(Doc):
    def __init__(self, mod, obj, *args, **kwds):
        self.mod = mod
        self.obj = obj
        self.args = args
        self.kwds = kwds

    def getstr(self):
        return '%s(%s%s)' % (
            self.obj.getstr(),
            ', '.join([x.getstr() for x in self.args]),
            ', '.join(['%s=%s' % (k, v.getstr()) for k, v in list(self.kwds.items())]))

    def mapchildren(self, f):
        obj = f(self.obj)
        args = [f(a) for a in self.args]
        kwds = dict([(k, f(v)) for (k, v) in list(self.kwds.items())])
        return self.__class__(self.mod, obj, *args, **kwds)


class Multi(Doc):
    def __init__(self, mod, set):
        self.mod = mod
        self.str = '{%s}' % ', '.join([x.getstr() for x in set])
        self.set = set

    def getstr(self):
        return self.str

    def mapchildren(self, f):
        return self.__class__(self.mod, dict([(f(x), 1) for x in self.set]))

    def shortest(self):
        ls = None
        for a in self.set:
            a = a.shortest()
            l = len(a.getstr())
            if ls is None or l < ls:
                ls = l
                st = a
        return st


class Root(Doc):
    def __init__(self, mod, name='<root>'):
        self.mod = mod
        self.name = name

    def __call__(self, name):
        return self.__class__(self.mod, name)

    def mapchildren(self, f):
        return self

    def getstr(self):
        return self.name


class Tuple(Doc):
    def __init__(self, mod, *args):
        self.mod = mod
        self.args = args

    def mapchildren(self, f):
        return self.__class__(self.mod, *[f(x) for x in self.args])

    def getstr(self):
        x = '(%s)' % ', '.join([x.getstr() for x in self.args])
        if len(self.args) == 1:
            x = x[:-1]+',)'
        return x


class DocError(Exception):
    pass


class _GLUECLAMP_:

    def add_origin(self, obj, origin):
        o = getattr(obj, '_origin_', None)
        if o is None:
            obj._origin_ = origin
        else:
            obj._origin_ = self.multi(o, origin)
        return obj

    def add_wrapdict(self, obj, doc):
        wd = self.wrapdict
        o = wd.get(id(obj))
        if o is None:
            o = (obj, doc)
        else:
            o = (obj, self.multi(o[1], doc))
        wd[id(obj)] = o
        return obj

    def anon(self, obj):
        return Anon(self, obj)

    def attribute(self, obj, name):
        return Attribute(self, self.getdoc(obj), name)

    def binop(self, op, a, b):
        return BinaryOp(self, op, self.getdoc(a), self.getdoc(b))

    def callfunc(self, obj, *args, **kwds):
        getdoc = self.getdoc
        obj = getdoc(obj)
        args = [getdoc(a) for a in args]
        kwds = dict([(k, getdoc(v)) for (k, v) in list(kwds.items())])
        return CallFunc(self, obj, *args, **kwds)

    def getdoc(self, obj):
        if isinstance(obj, Doc):
            return obj
        w = getattr(obj, '_origin_', None)
        if isinstance(w, Doc):
            return w
        w = self.wrapdict.get(id(obj))
        if w is not None:
            return w[1]
        if isinstance(obj, tuple):
            return self.tuple(*obj)
        return self.anon(obj)

    def multi(self, a, b):
        a = self.getdoc(a)
        b = self.getdoc(b)
        if isinstance(a, Multi):
            set = a.set.copy()
            if len(set) > 4:
                return a
        else:
            set = {a: 1}
        if isinstance(b, Multi):
            set.update(b.set)
        else:
            set[b] = 1
        return Multi(self, set)

    def _get_root(self):
        return Root(self)

    def rootattribute(self, root, name):
        return RootAttribute(self, self.getdoc(root), name)

    def source(self, text):
        return Source(self, text)

    def tuple(self, *args):
        return Tuple(self, *[self.getdoc(x) for x in args])

    def unop(self, op, a):
        return UnaryOp(self, op, self.getdoc(a))

    def wrap(self, obj, doc):
        assert obj is not self._parent.UniSet.UniSet
        w = getattr(obj, '_derive_origin_', None)
        if w is not None:
            if getattr(w, 'im_self', None) is obj or isinstance(w, self._root.types.MethodType):
                obj = w(doc)
            elif w == 'ADD':
                obj = self.add_origin(obj, doc)
            else:
                raise DocError(
                    "Doc.wrap:  attribute '_derive_origin_' has invalid value")
        elif isinstance(obj, self._root.types.MethodType):
            obj = self.wrap_method(obj, doc)
        elif isinstance(obj, self._root.types.FunctionType):
            obj = self.wrap_function(obj, doc)
        else:
            obj = self.add_wrapdict(obj, doc)
        return obj

    def _get_wrapdict(self):
        return {}

    def wrap_function(mod, obj, doc):
        def f(*args, **kwds):
            r = obj(*args, **kwds)
            r = mod.wrap(r, mod.callfunc(doc, *args, **kwds))
            return r
        f._origin_ = doc
        return f

    def wrap_method(mod, obj, doc):
        im_func = obj.__func__

        def f(self, *args, **kwds):
            r = im_func(self, *args, **kwds)
            r = mod.wrap(r, mod.callfunc(doc, *args, **kwds))
            return r
        return mod._root.types.MethodType(f, obj.__self__)