"""
Contains some experimental set constructions.
In the current state, not to be used by the faint-hearted.
It is likely due for some major refactoring and has probably
many bugs, it was a long time since I run the tests.
You don't get any other documentation than this right now.

"""


DEBUG = 1


def briefstr(x):
    try:
        return getattr(x, 'brief')
    except AttributeError:
        if isinstance(x, tuple):
            return '(%s)' % (','.join([briefstr(xi) for xi in x]))
        return str(x)


class SpecFamily:
    def __init__(self, unisetmod, specmod):
        self.specmod = specmod
        self.defrefining(unisetmod.Anything)
        self.disjoints -= [self]

    def __call__(self, arg):
        return self.Set(self, arg)

    def c_and(self, a, b):
        if isinstance(b, SpecFamily):
            return self.mod.fam_And._cons((a, b))
        else:
            return b.fam._and_ATOM(b, a)

    def _and_ID(self, a, b):
        env = self.specmod._static_test_env
        res = self.mod.mutnodeset()
        for bi in b.nodes:
            try:
                env.test_contains(a, bi, 'select contains')
            except Exception:  # TestError
                pass
            else:
                res.add(bi)
        return self.mod.fam_Identity._cons(self.mod.immnodeset(res))

    def c_contains(self, a, b):
        env = self.specmod._static_test_env
        try:
            return env.test_contains(a, b, 'Spec contains')
        except TestError:
            return False

    def c_getlimstr(self, a, max_len):
        x = a.brief
        if len(x) > max_len:
            x = x[:max_len-3]+'...'
        return x

    def c_get_brief(self, a):
        return '<%s(%s)>' % (self.__class__.__name__, briefstr(a.arg))


class ArgNamesFamily(SpecFamily):
    def __call__(self, *args):
        return self.Set(self, args)

    def getargnames(self, code):
        inspect = self.specmod._root.inspect
        (args, varargs, varkw) = inspect.getargs(code)
        if varargs is not None:
            args.append('*%s' % varargs)
        if varkw is not None:
            args.append('**%s' % varkw)
        return tuple(args)

    def func_argnames(self, f, args):
        try:
            code = f.__code__
            return self.getargnames(code) == args
        except AttributeError:
            return False

    def meth_argnames(self, m, args):
        try:
            f = m.__func__
            code = f.__code__
            return self.getargnames(code)[1:] == args
        except AttributeError:
            return False

    def c_contains(self, a, x):
        def func_argnames(f): return self.func_argnames(f, a.arg)
        def meth_argnames(m): return self.meth_argnames(m, a.arg)
        types = self.mod._root.types
        return (func_argnames(x) or
                meth_argnames(x) or
                (isinstance(x, type) and
                 (hasattr(x, '__init__') and
                  meth_argnames(x.__init__))) or
                (isinstance(x, type) and
                 (hasattr(x, '__init__') and
                  meth_argnames(x.__init__))) or
                (hasattr(x, '__call__') and
                 meth_argnames(x.__call__))
                )


class AttributeFamily(SpecFamily):
    def __call__(self, name, type=None):
        if type is None:
            type = self.specmod.any
        else:
            if not isinstance(type, self.mod.UniSet):
                type = self.c_from(type)
        return self.specotup((name, type))

    def c_test_contains(self, a, b, env):
        name, type = a.arg
        x = env.gengetattr(b, name)
        return type.test_contains(x, env)

    def c_get_brieflimstr(self, a):
        x = '<AttributeFamily(%r%%s>' % (a.arg[0],)
        if a.arg[1] is not None:
            x = x % (','+a.arg[1].brief)
        else:
            x = x % ''
        return x


class AdaptupleFamily(SpecFamily):
    def __init__(self, *a, **k):
        SpecFamily.__init__(self, *a, **k)
        self.add_export('new', lambda x: x.arg[0])

    def __call__(self, func, type):
        func, doc = self.specmod._exodoc(func)
        type = self.specmod.setcast(type)
        return self.specoargtup((func, type), (doc, type))

    def c_test_contains(self, a, b, env):
        func, type = a.arg
        if isinstance(b, tuple):
            try:
                x = func(*b)
            except Exception:
                return env.failed_exc_info('calling func failed')
        else:
            x = b
        return type.test_contains(x, env)


class CartesianProductFamily(SpecFamily):
    def __call__(self, *types):
        return self.Set(self, types)

    def c_domain(self, a):
        types = a.arg
        if len(types) == 2:
            return types[0]
        raise TypeError('Domain is defined on binary relations only')

    def c_get_examples(self, a, env):
        # We have to check length before calling iterpermute -
        # to give a reasonable error message examples are missing from some set.
        exs = []
        for i, ai in enumerate(a.arg):
            ex = list(env.get_examples(ai))
            if not ex:  # ???
                if not env.failed_coverage('cartesian product', ai, None, 'the argument #%d' % i):
                    return []
            exs.append(ex)

        return self.mod._root.guppy.etc.iterpermute(*exs)

    def c_len(self, a):
        l = 1
        for ai in a.arg:
            l = l * len(ai.arg)
        return l

    def c_test_contains(self, a, b, env):
        types = a.arg
        bs = tuple(b)
        if len(types) != len(bs):
            env.failed('cprod of length %d: argument has length %d' %
                       (len(types), len(bs)))
        else:
            for t, b in zip(types, bs):
                if not t.test_contains(b, env):
                    return False
            return True


class SequenceFamily(SpecFamily):
    def __call__(self, type):
        return self.specoarg(type)

    def c_test_contains(self, a, b, env):
        for x in b:
            if not a.arg.test_contains(x, env):
                return False
        return True

    def c_get_examples(self, a, env):
        for i in range(env.max_sequence_examples_length):
            for x in env.get_examples(self.specmod.cprod(*[a.arg]*i)):
                yield x


class MappingFamily(SpecFamily):
    def __init__(self, *a, **k):
        SpecFamily.__init__(self, *a, **k)
        self.add_export('arrow', lambda x: lambda f: self.c_arrow(x, f))

    def c_arrow(self, a, f):
        tf, ts, ret = a.arg
        return Arrow(ts, ret, f)

    def __call__(self, *args):
        ts = []
        as_ = []
        ret = None
        i = 0
        setcast = self.specmod.setcast
        while i < len(args):
            ai = args[i]
            if isinstance(ai, str):
                if ai == '->':
                    i += 1
                    if not i == len(args)-1:
                        raise SyntaxError(
                            "The '->' specifier must be next to last in the argument list")
                    ret = setcast(args[i])
                elif ai.endswith('='):
                    i += 1
                    t = setcast(args[i])
                    as_.append('%s=%args[%d]' % (ai[:-1], len(ts)))
                    ts.append(t)
                elif ai == '*':
                    i += 1
                    t = setcast(args[i])
                    as_.append('*args[%d]' % len(ts))
                    ts.append(self.specmod.sequence(t))
                else:
                    raise SyntaxError("Invalid argument specifier: %r" % ai)

            else:
                as_.append('args[%d]' % len(ts))
                ts.append(setcast(ai))
            i += 1

        fn = 'lambda f: lambda *args: f('+','.join(as_)+')'
        f = eval(fn)
        ts = self.specmod.cprod(*ts)
        if ret is None:
            ret = self.specmod.Anything
        return self.Set(self, (f, ts, ret))

    def c_test_contains(self, a, func, env):
        f, ts, ret = a.arg

        f = f(func)

        def g(env, args):
            try:
                r = f(*args)
            except Exception:  # TypeError, ValueError, AttributeError ... - what not
                raise
                #env.failed('Call exception')
            else:
                if ret is not None:
                    return env.test_contains(ret, r, "Mapping Return Type")
                else:
                    return True

        return env.forall(ts, g)

    def c_get_examples(self, a, env):
        f, ts, ret = a.arg

        return [lambda *args, **kwds: x for x in env.get_examples(ret)]


class PredicateFamily(SpecFamily):
    def __call__(self, arg, doc):
        return self.Set(self, (arg, doc))

    def c_test_contains(self, a, b, env):
        pred, doc = a.arg
        if not pred(env, b):
            return env.failed('pred: doc = %r; failed for element == %s' % (doc, env.name(b)))
        return True


class PowersetFamily(SpecFamily):
    def __init__(self, *args):
        SpecFamily.__init__(self, *args)
        self.add_export('union', lambda x: x.arg)

    def __call__(self, set):
        return self.specoarg(set)

    def c_get_examples(self, a, env):
        x = [self.specmod.Nothing, a.arg]
        try:
            y = env.get_examples(a.arg)
        except Exception:
            # xxx complain? We can always generate 2 examples..
            return x
        # xxx should we make all permutations?..
        return x

    def c_test_contains(self, a, b, env):
        if not b in self.specmod.set:
            env.failed('powerset.test_contains: not a set: %s' %
                       self.specmod.iso(b))
        set = a.arg
        return env.forall(b, lambda env, x: env.test_contains(set, x, 'powerset'), 'powerset')


class DocFamily(SpecFamily):
    def __call__(self, doc, type=None):
        if type is None:
            type = self.specmod.UniSet.NotNothing
        else:
            if not type in self.specmod.set:
                type = self.specmod.UniSet.convert(type)
        return self.Set(self, (doc, type))

    def c_test_contains(self, a, b, env):
        doc, type = a.arg
        return type.test_contains(b, env)


class RelOpFamily(SpecFamily):
    def __init__(self, *a, **k):
        SpecFamily.__init__(self, *a, **k)
        self.add_export('domain', lambda x: x.arg[0])
        self.add_export('range', lambda x: x.arg[2])
        # The memo dict keeps relops with the same domain, op, and range.
        # Primarily introduced to make equality work with default mechanism,
        # since different compiled func's compared differently even with
        # the same source.
        self.memo = {}

    def __call__(self, domain, op, range=None):
        domain = self.specmod.setcast(domain)
        if range is None:
            range = domain
        else:
            range = self.specmod.setcast(range)
        x = self.memo.get((domain, op, range))
        if x is None:
            if op in ('<', '<=', '==', '!=', '>', '>=', 'in', 'not in', 'is', 'is not'):
                func = eval('lambda x,y: x %s y' % op)
                func.name = op
            else:
                func = op
                func.name = func.__name__
            x = self.Set(self, (domain, func, range))
            self.memo[(domain, op, range)] = x
        return x

    def c_get_examples(self, a, env):
        # We have to check length before calling iterpermute -
        # to give a reasonable error message examples are missing from some set.
        dom = list(env.get_examples(a.domain))
        if not dom:
            failed_coverage('relation', a.domain, None, 'domain')
            return []

        ran = list(env.get_examples(a.range))
        if not ran:
            failed_coverage('relation', a.range, None, 'range')
            return []

        exs = []
        for ex in self.specmod._root.guppy.etc.iterpermute(dom, ran):
            if env.contains(a, ex):
                exs.append(ex)
        return exs

    def c_test_contains(self, a, b, env):
        d, op, r = a.arg
        if not op(*b):
            return env.failed()
        return True


class EqualsFamily(SpecFamily):
    def __call__(self, *args):
        if not args:
            return self.specmod.Nothing
        return self.specotup(args)

    def c_test_contains(self, a, b, env):
        if b in a.arg:
            return True
        return env.failed('equals')

    def c_get_examples(self, a, env):
        return a.arg


class ExampleFamily(SpecFamily):
    def __call__(self, set, *examples):
        return self.Set(self, (set, examples))

    def c_test_contains(self, a, b, env):
        set, examples = a.arg
        return set.test_contains(b, env)

    def c_get_examples(self, a, env):
        set, examples = a.arg
        # for e in examples:        env.test_contains(set, e, 'ExampleFamily.c_get_examples')
        return examples


class SynonymsFamily(SpecFamily):
    def __call__(self, *names):
        return self.Set(self, names)

    def c_test_contains(self, a, b, env):
        names = a.arg
        ms = self.specmod.UniSet.mutnodeset()
        for name in names:
            x = env.getattr(b, name)
            ms.add(x)
        if not len(ms):
            env.failed('Synonyms: no such names: %r' % names)
        if len(ms) > 1:
            env.failed('Synonyms: %d different nodes for names: %r' %
                       (len(ms), names))
        return True


class InstanceFamily(SpecFamily):
    def c_test_contains(self, a, b, env):
        if not isinstance(b, a.arg):
            env.failed('InstanceFamily: %s is not an instance of %s' % (
                self.specmod.iso(b), a.arg))
        return True

    def c_get_examples(self, a, env):
        return env.get_examples(self.specmod.setcast(a.arg))

    def _and_ID(self, a, b):
        return self.mod.fam_Identity(*[bi for bi in b.nodes if isinstance(bi, a.arg)])


class ExpressionPredicateFamily(SpecFamily):
    def __call__(self, names, expression):
        func = None
        return self.Set(self, (names, expression, func))

    def c_test_contains(self, a, b, env):
        names, expression, func = a.arg
        func = eval('lambda %s:%s' % (','.join(names), expression))
        d = {}
        for name in names:
            x = env.getattr(b, name)
            d[name] = x
        x = func(**d)
        if not x:
            env.failed('False expression: %s' % expression)
        return True


class ExpressionSetFamily(SpecFamily):
    def __call__(self, expression, *names):
        func = None
        return self.Set(self, (names, expression, func))

    def c_test_contains(self, a, b, env):
        names, expression, func = a.arg
        func = self.specmod.eval('lambda %s:(%s)' % (
            ','.join(('LE',)+tuple(names)), expression))
        d = {'LE': env.LE}
        for name in names:
            x = env.getattr(b, name)
            d[name] = x
        x = func(**d)
        return env.test_contains(x, b, 'expset(%s, %s)' % (expression, ','.join(names)))


class MatchesFamily(SpecFamily):
    def __init__(self, *a, **k):
        SpecFamily.__init__(self, *a, **k)
        self.sre = self.specmod._root.sre

    def __call__(self, regexp):
        return self.specoargtup(self.sre.compile(regexp), (regexp,))

    def c_test_contains(self, a, b, env):
        regexpobj = a.arg
        m = self.sre.match(regexpobj, b)
        if m is None:
            return env.failed('Did not match')
        return True


class RecurSelfFamily(SpecFamily):
    def __init__(self, *a, **k):
        SpecFamily.__init__(self, *a, **k)

        class RecurSpec(self.Set):
            __slots__ = 'func', 'recursion_level', 'recursion_limit'

        self.RecurSpec = RecurSpec

    def __call__(self, expr, recursion_limit=10):
        s = self.RecurSpec(self, expr)
        s.recursion_limit = recursion_limit
        s.recursion_level = 0
        return s

    def c_test_contains(self, a, b, env):
        try:
            func = a.func
        except AttributeError:
            expr = a.arg
            func = a.func = env.eval('lambda self:%s' % expr)
        s = func(self.specmod.Nothing)
        try:
            tf = env.test_contains(s, b, 'recur with Nothing, ok to fail')
            if not tf:
                raise TestError
        except Exception:  # TestError: eg for match, we got a TypeError..
            s = func(a)
            rl = a.recursion_level
            try:
                if rl >= a.recursion_limit:
                    return env.failed('recurself: recursion_level = %s' % a.recursion_limit)
                else:
                    a.recursion_level = rl + 1
                tf = env.test_contains(s, b, 'recur')
            finally:
                a.recursion_level = rl
        return tf


class Dummy:
    pass


class TupleformFamily(SpecFamily):
    def __call__(self, form, set):
        return self.specotup((form, set))

    def c_test_contains(self, a, b, env):
        form, set = a.arg

        bt = tuple(b)

        if len(bt) != len(form):
            return env.failed('tupleform: wrong length: got %d expected %d' % (len(bt), len(form)))

        ob = Dummy()
        for name, val in zip(form, bt):
            setattr(ob, name, val)

        return env.test_contains(set, ob, 'tupleform')


class Arrow:
    def __init__(self, category, source, target):
        self.category = category
        self.source = source
        self.target = target

    def of(self, other):
        # compose self <-- other
        # (Standard composition order)
        other = self.category.validate(other)
        return self.category.compose(self, other)

    def to(self, other):
        # compose self --> other
        # (Nonstandard composition order; sometimes seems more natural)
        other = self.category.validate(other)
        return self.category.compose(other, self)


class IdentityArrow(Arrow):
    def __init__(self, category, object):
        Arrow.__init__(self, category, object, object)

    def __call__(self, x):
        return x


class FunctionArrow(Arrow):
    def __init__(self, category, source, target, function):
        Arrow.__init__(self, category, source, target)
        self.__call__ = function


class RepresentationCategory:
    _derive_origin_ = None
    _origin_ = None

    def __init__(self, mod, spec):
        fam = mod.family(RepresentationObjectFamily)
        fam.init2(self, spec)
        self._fam = fam

    def __eq__(self, other):
        return self is other

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

    def __getattr__(self, name):
        r = self._fam.getobject(name)
        self.__dict__[name] = r
        return r


class RepresentationObjectFamily(SpecFamily):
    def init2(self, cat, spec):
        self.cat = cat
        self.objects = {}
        self.specs = {}
        self.arrows = {}

        self.add_export('fromuniversal', self.fromuniversal)

        Set = self.Set

        class RepresentationObject(Set):
            __slots__ = 'to', 'from'

        self.Set = RepresentationObject

        class RepresentationCategorySpec(spec):
            def __init__(self, fam):
                self._fam = fam
                self._cat = fam.cat

            def __getattr__(self, name):
                if hasattr(self.__class__, '_get_%s' % name):
                    r = getattr(self, '_get_%s' % name)(self._fam.specmod)
                    self.__dict__[name] = r
                    return r
                raise AttributeError(name)

        self.spec = RepresentationCategorySpec(self)

    def getarrow(self, dom, cod):
        dc = (dom, cod)
        if dc in self.arrows:
            return self.arrows[dc]

        raise SpecError

    def getobject(self, name):
        if name in self.objects:
            return self.objects[name]
        normname = self.normoname(name)
        if normname in self.objects:
            self.objects[name] = self.objects[normname]
            return self.objects[normname]

        o = self(normname)
        self.objects[normname] = self.objects[name] = o
        return o

        raise SpecError('No such object: %r' % name)

    def getspec(self, obj):
        name = obj.arg
        if name in self.specs:
            return self.specs[name]

        gs = getattr(self.spec, '_get_spec_%s' % name, None)
        if gs is not None:
            sp = gs(self.specmod)
            self.specs[name] = sp
            return sp

        raise SpecError('getspec: No spec of %r' % name)

    def fromuniversal(self, target):
        # Find a most general arrow into 'target'
        # 1. Find all predefined arrows to target
        # 2. Make a category sum of the set of sources S of all such arrows
        # 3. Make a specification-set P for this sum, which is that:
        #    a. The element should be isomorphic to a tuple (O, A) where
        #    b. O, the tag, should be an object in S
        #    c. A, the value,  should be an element in O

        # Return an arrow taking this object to target.
        #
        # Arrows thus created are memoized.

        name = target.arg
        arrowname = '%s.fromuniversal' % name
        if arrowname in self.arrows:
            return self.arrows[arrowname]

        S = {}

        S[name] = IdentityArrow(self.cat, target)

        for an in dir(self.spec):
            if not (an.startswith('map_') and '_to_' in an):
                continue
            s, t = an.split('_to_')
            s = s[4:]
            if t == name:
                f = getattr(self.spec, an)
                S[s] = FunctionArrow(self.cat, getattr(self.cat, s), target,
                                     lambda x: f(self.specmod, x))

        def p(env, e):
            try:
                O, A = e
            except Exception:
                return env.failed('Not a sequence with length 2')
            fam = getattr(O, 'fam', None)
            if fam is not self:
                return env.failed('Tag is not an object of this family')
            name_ = getattr(O, 'arg', None)
            if name_ not in S:
                return env.failed('Object is not a source of this target')
            return env.test_contains(O, A, 'Value is not an element of this object')

        uniname = '%s.universal' % name
        P = self.specmod.predicate(p, 'Specification-set for %r' % uniname)
        self.specs[uniname] = P
        source = self(uniname)

        class AlphaSum(Arrow):
            def __init__(self, category, source, target, S):
                Arrow.__init__(self, category, source, target)

                self._S = S

            def __getitem__(self, x):   # Don't know what to call this unique arrow
                return self._S[self.source.fam.normoname(x)]

            def __call__(self, xxx_todo_changeme):
                (O, E) = xxx_todo_changeme
                return self[O.arg](E)

        arrow = AlphaSum(self.cat, source, target, S)
        self.arrows[arrowname] = arrow
        return arrow

    def normoname(self, on):
        isos = getattr(self.spec, '_isos_', None)
        if isos is not None:
            for l in self.spec._isos_:
                nn = None
                for n in l:
                    if n.isdigit():
                        nn = n
                    if n == on:
                        if nn is not None:
                            return nn
                        raise SpecError(
                            'No numeric object name corresponding to %r' % on)
        return on

    def __call__(self, name):
        r = self.specoarg(name)

        class To:
            __slots__ = 'source',

            def __init__(self, source):
                self.source = source

            def __call__(self, target):
                return self.source.fam.getarrow(self.source, target)

            def __getattr__(self, name):
                source = self.source
                fam = source.fam
                target = fam.getobject(name)
                return fam.getarrow(source, target)

        r.to = To(r)
        return r

    def c_test_contains(self, a, b, env):
        set = self.getspec(a)
        return env.test_contains(set, b, 'RepresentationObjectFamily: not in object specification')

    def c_get_examples(self, a, env):
        set = self.getspec(a)
        return env.get_examples(set)


class AbstractSetFamily(SpecFamily):
    def __init__(self, *a, **k):
        SpecFamily.__init__(self, *a, **k)

        class AbstractSet(self.Set):
            __slots__ = '_memo',

            def __init__(self, fam, arg):
                self.fam = fam
                self.arg = arg
                self._origin_ = None
                self._memo = {}
        self.Set = AbstractSet

    def __call__(self, arrow, set):
        r = self.specotup((arrow, set))
        r._memo = {}
        return r

    def c_and(self, a, b):
        if b.fam is self:
            aa, sa = a.arg
            ab, sb = b.arg
            if aa is ab:
                return self(aa, sa & sb)
        return b.fam._rand_ATOM(b, a)

    def c_getattr2(self, a, b):
        if b in a._memo:
            return a._memo[b]
        arrow, set = a.arg

        pararrow = arrow[b]
        srcset = pararrow.source

        def p(env, x):
            t = env.test_contains(
                srcset, x, 'AbstractSet: not in arrow.source')
            if t:
                e = pararrow(x)
                t = env.test_contains(
                    set, e, 'AbstractSet: not in argument set')
            return t

            return env.contains(set, y)

        s = self.specmod.predicate(p, 'Abstract set attribute: %r' % b)  # ...
        a._memo[b] = s
        return s

    def c_test_contains(self, a, b, env):
        arrow, set = a.arg
        t = env.test_contains(
            arrow.source, b, 'AbstractSet: not in arrow.source')
        if t:
            e = arrow(b)
            t = env.test_contains(set, e, 'AbstractSet: not in argument set')
        return t


class ElemFamily(SpecFamily):
    def __call__(self, func):
        return self.specoarg(func)

    def c_test_contains(self, a, b, env):
        func = a.arg
        s = func(b)
        return env.test_contains(s, b, 'ElemFamily')


class IntersectionFamily(SpecFamily):
    def __call__(self, domain, function):
        return self.specotup((domain, function))

    def c_test_contains(self, a, b, env):
        domain, function = a.arg
        return env.forall(domain, lambda env, x:
                          env.test_contains(function(x), b, 'Intersection'))


class SpecError(Exception):
    pass


class TestError(Exception):
    pass


class CoverageError(Exception):
    pass


class LocalEnv:
    _derive_origin_ = 'ADD'

    def __init__(self, mod, spec, nodoc=1):
        self._mod = mod
        self._spec = spec
        self._origin_ = None
        self.nodoc = nodoc

    def __getattr__(self, attribute_name):
        mod = self._mod
        f = getattr(self._spec, attribute_name)
        d = self._mod._load_names(
            mod._root.guppy.etc.Code.co_findloadednames(f.__code__))
        nf = mod._root.types.FunctionType(
            f.__code__,
            d,
            f.__name__,
            f.__defaults__,
            f.__closure__)
        r = nf(())
        self.__dict__[attribute_name] = r
        return r


class TestEnv:
    _derive_origin_ = 'ADD'
    iscomplete = False
    issilent = False
    # ie. (), cprod(x) cprod(x, y) are yielded by default
    max_sequence_examples_length = 2
    TestError = TestError

    def __init__(self, mod, Spec):
        self.mod = mod
        self.messages = []
        self.examples = {}
        if Spec is not None:
            self.spec = spec = Spec()
            try:
                lex = spec.LocalEnvExpr
            except AttributeError:
                lex = ''
            LE = LocalEnv(mod, lex)
            LE._OBJ_ = mod
            self.LE = LE

            self.topspec = self.eval(spec.GlueTypeExpr)

    def eval(self, expr):
        mod = self.mod
        types = mod._root.types
        if isinstance(expr, (str,)):
            func = self.mod.eval('lambda LE:(\n%s\n)' % expr)
            return func(self.LE)

        ls = []
        selfset = None

        names = list(expr.__dict__.keys())
        names.sort()

        for name in names:
            f = getattr(expr, name)
            try:
                co = f.__code__
            except AttributeError:
                continue
            if co.co_varnames[:co.co_argcount] == ('IN',):
                d = mod._load_names(
                    mod._root.guppy.etc.Code.co_findloadednames(co))
                #d = mod._load_names()

                nf = mod._root.types.FunctionType(
                    f.__code__,
                    d,
                    f.__name__,
                    f.__defaults__,
                    f.__closure__)
                s = nf(())
                if name == '_SELF_':
                    selfset = s
                else:
                    ls.append(mod.attr(name, s))
            else:
                raise SpecError('TestEnv.eval: invalid argument mode')
        # Constructing an AND in one sweep = faster
        # We assume they are not disjoint - which
        # would be determined by testing that we are going to do
        # (We know they are all attr's of different names here)

        # Except that selfset may perhaps be disjoint; but why care here
        #
        if selfset is not None:
            ls.append(selfset)

            # Alternatively: r = r & selfset afterwards,
            # but could be unnecessarily slow

        r = mod.UniSet.fam_And._cons(ls)
        return r

    def get_examples(self, collection):
        try:
            it = iter(collection)
        except TypeError:
            try:
                ex = self.examples[collection]
            except KeyError:
                if isinstance(collection, self.mod.UniSet.UniSet):
                    ex = collection.get_examples(self)
                else:
                    ex = list(collection)
            it = iter(ex)
        return it

    def getattr(self, obj, name):
        if '.' in name:
            x = obj
            for subname in name.split('.'):
                try:
                    x = getattr(x, subname)
                except Exception:
                    return self.failed('getattr: %s has no attribute %r' % (self.name(obj), name) +
                                       ',\nbecause %s has no attribute %r' % (self.name(x), subname))
        else:
            try:
                x = getattr(obj, name)
            except Exception:
                if DEBUG:
                    raise
                return self.failed('attr: %s has no attribute %r' % (self.name(obj), name))
        return x

    def gengetattr(self, obj, name_or_tuple):
        if isinstance(name_or_tuple, str):
            return self.getattr(obj, name_or_tuple)
        elif isinstance(name_or_tuple, tuple):
            if len(name_or_tuple) == 2 and name_or_tuple[0] is self.mod.quote:
                return name_or_tuple[1]
            else:
                return tuple([self.gengetattr(obj, nt) for nt in name_or_tuple])
        else:
            raise TypeError('gengetattr: I am picky, required string or tuple')

    def log(self, message):
        self.messages.append(message)

    def name(self, obj):
        if isinstance(obj, self.mod.UniSet.UniSet):
            return str(obj)
        else:
            return '%s' % self.mod.iso(obj)

    def name_coll(self, collection):
        return '%s' % collection

    def test(self, obj):
        self.get_obj_examples(obj)
        try:
            self.test_contains(self.topspec, obj, 'Top spec')
        except Exception:
            tvt = self.mod._root.sys.exc_info()
            self.dump_failure(tvt)

    def get_obj_examples(self, obj):
        ex = self.spec.GetExamples(self, obj)
        for e in ex:
            vs = e[1:]
            e = e[0]
            s = self.examples.setdefault(e, [])
            for v in vs:
                s.append(v)
                self.test_contains(e, v, 'testing example of set')

    def dump_failure(self, xxx_todo_changeme3, noraise=0):
        (type, value, traceback) = xxx_todo_changeme3
        list = []
        tb = traceback
        while tb is not None:
            f = tb.tb_frame
            if f.f_code is self.test_contains.__func__.__code__:
                list.append(f)
            tb = tb.tb_next
        for f in list:
            lo = f.f_locals
            print('a = %r' % (lo['a'],))
            print('b = %r' % (lo['b'],))
            print('message = ', lo['message'])
            print('-----')
        if noraise:
            self.mod._root.traceback.print_exception(type, value, traceback)
        else:
            raise

    def contains(self, a, b):
        try:
            x = self.test_contains(a, b, 'contains')
        except CoverageError:
            raise
        except Exception:
            return False
        return x

    def test_contains(self, a, b, message):
        return a.test_contains(b, self)

    def test_contains_not(self, a, b, message):
        try:
            a.test_contains(b, self)
        except CoverageError:
            raise
        except Exception:  # TestError: # well we axcept anything.. ok?
            return True
        else:
            return self.failed('test_contains_not, from: %s' % message)

    def failed(self, message=''):
        if not self.issilent:
            self.log('Failed:' + message)
            raise TestError(message)
        return False

    def failed_coverage(self, forwhat, collection, func, message):
        if collection is self.mod.Nothing:
            return True
        raise CoverageError('%s: no examples for collection = %s, message: %s' % (
            forwhat, collection, message))

    def failed_exc_info(self, message):
        exc_info = self.mod._root.sys.exc_info()
        type, value, traceback = exc_info
        if not self.issilent:
            self.log('Failed:' + message)
            raise type(value)
        return False

    def forall(self, collection, func, message=''):
        ex = self.get_examples(collection)
        n = 0
        for e in ex:
            if not func(self, e):
                return self.failed('forall: e = %s, from: %s' % (self.name(e), message))
            n += 1
        if not n:
            try:
                a = len(collection)
                if a > 0:
                    raise CoverageError
                # Otherwise ok, it was really an Nothing collection.
            except Exception:
                self.failed_coverage('forall', collection, func, message)

        return True

    def forall_pairs(self, collection, func, message=''):
        as_ = self.get_examples(collection)
        n = 0
        for a in as_:
            for b in self.get_examples(collection):
                if not func(self, a, b):
                    self.failed('forall_pairs: a = %s, b = %s, from: %s' % (
                        self.name(a), self.name(b), message))
                n += 1
        if not n:
            self.failed_coverage('forall_pairs', collection, func, message)
        return True

    def forall_triples(self, collection, func, message=''):
        as_ = self.get_examples(collection)
        n = 0
        for a in as_:
            for b in self.get_examples(collection):
                for c in self.get_examples(collection):
                    if not func(self, a, b, c):
                        self.failed('forall_triples: a = %s, b = %s, c=%s, from: %s' % (
                            self.name(a), self.name(b), self.name(c), message))
                    n += 1
        if not n:
            self.failed_coverage('forall_triples', collection, func, message)
        return True

    def forsome(self, collection, func, message=''):
        failures = []
        for i, x in enumerate(collection):
            try:
                b = func(x)
            except Exception:  # TestError:
                failures.append((i, self.mod._root.sys.exc_info()))
                continue
            if b:
                return True
        for (i, tvt) in failures:
            print('forsome: exception at collection[%d]:' % i)
            self.dump_failure(tvt, noraise=1)
        self.failed(message)


class _GLUECLAMP_:

    _chgable_ = '_loaded',
    _nowrap_ = ('_origin_', 'Doc', 'family', 'eval', 'setcast', 'compile', 'wrap_source_string',
                '_load_names', 'iso')

    _preload_ = '_hiding_tag_',

    # 'imports'

    _imports_ = (
        '_parent:Use',
        '_parent.Use:iso',
        '_parent.Use:Nothing',
    )

    def _get_UniSet(self): return self._parent.UniSet
    def _get_Doc(self): return self._parent.Doc
    def _get_View(self): return self._parent.View

    #

    def _get__origin_(self):
        return self.Doc.attribute(self.Doc.root, 'guppy.heapy.Spec')

    def _wrapattr_(self, obj, name):
        Doc = self.Doc
        if name == 'setof':
            pass
        try:
            obj = Doc.wrap(obj, Doc.attribute(self._origin_, name))
        except Doc.DocError:
            __import__('traceback').print_exc()
            print('no wrap:', name)
        return obj

    def _get_abstractset(self):
        return self.family(AbstractSetFamily)

    def _get_adaptuple(self):
        return self.family(AdaptupleFamily)

    def _get_any(self):
        return ~self.Nothing

    def _get_argnames(self):
        return self.family(ArgNamesFamily)

    def _get_attr(self):
        return self.family(AttributeFamily)

    def attrs(self, names, type=None):
        x = self.any
        for n in names:
            x &= self.attr(n, type)
        return x

    def _get_boolean(self):
        def p(env, x):
            try:
                if x:
                    pass
            except Exception:
                env.failed("boolean: 'if x' raised an exception")
            return True
        return self.predicate(p, 'boolean')

    def _get_callable(self):
        return self.predicate(lambda env, x: callable(x), 'callable')

    def _get_compile(self):
        token = self._root.token
        parser = self._root.parser
        symbol = self._root.symbol

        def mapchildren_id(node, f):
            return node

        def mapchildren_default(node, f):
            return [node[0]] + [f(n) for n in node[1:]]

        mapchildren_dispatch = dict(
            [(value, mapchildren_id) for value in range(token.N_TOKENS)])

        mapchildren_dispatch.update(dict([(value, mapchildren_default)
                                          for value, name in list(symbol.sym_name.items())]))

        def mapchildren(node, f):
            return mapchildren_dispatch[node[0]](node, f)

        def visitor(C):
            d = mapchildren_dispatch.copy()
            for value, name in list(symbol.sym_name.items()):
                if hasattr(C, name):
                    d[value] = getattr(C, name).__func__

            def _visit(node): return d[node[0]](node, _visit)
            return _visit

        def recover_source_node(node, l):
            for n in node[1:]:
                recover_source_dispatch[n[0]](n, l)

        def recover_source_token(node, l):
            if l and l[-1] != '(':
                l.append(' ')
            l.append(node[1])

        def recover_source_name(node, l):
            if l and l[-1] not in ('.', '('):
                l.append(' ')
            l.append(node[1])

        def recover_source_tight_left(node, l):
            l.append(node[1])

        def recover_source_lpar(node, l):
            if l and not (l[-1][-1:].isalnum() or l[-1] == '('):
                l.append(' ')
            l.append(node[1])

        recover_source_dispatch = dict([(value, recover_source_node)
                                        for value, name in list(symbol.sym_name.items())])
        recover_source_dispatch.update(
            dict([(value, recover_source_token) for value in range(token.N_TOKENS)]))

        recover_source_dispatch[token.NAME] = recover_source_name

        for tok in ('RPAR', 'LSQB', 'RSQB', 'COLON', 'COMMA', 'SEMI',
                    'DOT', 'LBRACE', 'RBRACE'):
            recover_source_dispatch[getattr(
                token, tok)] = recover_source_tight_left

        recover_source_dispatch[token.LPAR] = recover_source_lpar

        def recover_source(node):
            l = []
            recover_source_dispatch[node[0]](node, l)
            return ''.join(l)

        class wrap_lambdef:
            def test(node, f):
                # and_test ('or' and_test)* | lambdef
                if len(node) == 2 and node[1][0] == symbol.lambdef:
                    lsource = recover_source(node[1])
                    lnode = mapchildren(node[1], f)

                    return (
                        292, (293, (294, (295, (297, (298, (299, (300, (301,
                                                                        (302, (303, (304, (305, (1, 'wrap_source_string')),
                                                                                     (308, (7, '('), (317, (318, (292, lnode)), (12, ','),
                                                                                                      (318, (292, (293, (294, (295, (297, (298, (299, (300,
                                                                                                                                                       (301, (302, (303, (304, (305, (3, '%r' % lsource
                                                                                                                                                                                      )))))))))))))))), (8, ')'))))))))))))))

                return mapchildren(node, f)

        wrap_lambdef = visitor(wrap_lambdef)

        def compile_(source, filename, mode, *args):
            if mode != 'spec':
                return compile(source, filename, mode, *args)
            ast = parser.expr(source)
            node = parser.ast2tuple(ast, line_info=1)
            node = mapchildren(node, wrap_lambdef)

            ast = parser.tuple2ast(node)

            co = parser.compileast(ast)
            return co

        return compile_

    def _get_cprod(self):
        return self.family(CartesianProductFamily)

    def dictof(self, set=None):
        return self.UniSet.byclodo.dictof(set)

    def _get_doc(self):
        return self.family(DocFamily)

    def docof(self, set):
        doc = (set.doc % self._origin_).shortest()
        do = str(doc)
        print(do)
        return do

    def eval(self, expr, init=None, nodoc=0):
        if nodoc:
            mode = 'eval'
        else:
            mode = 'spec'
        co = self.compile(expr, '', mode)

        d = self._load_names(self._root.guppy.etc.Code.co_findloadednames(co))
        if init is not None:
            d = d.copy()
            exec(init, d)

        return eval(co, d)

    def _get_all_names(self):
        names = {'_root': 1}
        for x in _GLUECLAMP_.__dict__:
            if x.startswith('_get_'):
                x = x[5:]
            names[x] = 1
        return names

    def _load_names(self, names=None):
        if names is None:
            if '_loaded' not in self.__dict__:
                for x in self.all_names:
                    getattr(self, x)
                self._loaded = 1
        else:
            all = self.all_names
            for name in names:
                if name in all:
                    getattr(self, name)
        d = self.__dict__
        d['__builtins__'] = self._load_names.__globals__['__builtins__']
        return d

    def _get_eg(self):
        return self.family(ExampleFamily)

    def _get_elem(self):
        return self.family(ElemFamily)

    def _exodoc(self, expr):
        if expr in self.LE.string:
            r = self.eval(expr)
            return r, self.Doc.anon(expr)
        elif (expr in self.Type.Function and
              expr.__code__.co_name == '<lambda>' and
              expr.__code__.co_filename.startswith('<!SPECEVAL!>')):
            fn = expr.__code__.co_filename
            lines = fn.split('\n')
            lnum = expr.__code__.co_firstlineno
            inspect = self._root.inspect
            print(lines[lnum:])
            block = inspect.getblock(lines[lnum:])
            source = '\n'.join(block)
            return expr, self.Doc.getdoc(source)

        else:
            return expr, self.Doc.getdoc(expr)

    def _get_expred(self):
        return self.family(ExpressionPredicateFamily)

    def _get_expression(self):
        def p(env, x):
            try:
                eval('lambda : %s' % x)
            except SyntaxError:
                env.failed('Not a valid expression: %r' % x)
            return True
        return self.predicate(p, 'expression')

    def _get_expset(self):
        return self.family(ExpressionSetFamily)

    def _get_equals(self):
        return self.family(EqualsFamily)

    def family(self, fam, *args, **kwds):
        return self.UniSet.fam_mixin_argatom(fam, self, *args, **kwds)

    def _get__hiding_tag_(self):
        return self.UniSet._hiding_tag_

    def _get_instance(self):
        return self.family(InstanceFamily)

    def _get_intersection(self):
        return self.family(IntersectionFamily)

    def _get_LE(self):
        return LocalEnv(self, self._Specification_.LocalEnvExpr)

    def _get_SPLE(self):
        return self.LE

    def _get_mapping(self):
        return self.family(MappingFamily)

    def _get_matches(self):
        return self.family(MatchesFamily)

    def mkTestEnv(self, Spec):
        return TestEnv(self, Spec)

    def newtype(self, name):
        return self.predicate(lambda e, x: 1, name)  # xxx new family?

    def _get_nothing(self):
        return self.Use.Nothing

    def partition(self, set):
        return self.doc('partition',
                        self.union_equals(set) &
                        self.LE.nonempty &
                        self.set_of_disjoint_sets
                        )

    def _get_predicate(self):
        return self.family(PredicateFamily)

    def _get_powerset(self):
        return self.family(PowersetFamily)

    def _get_Anything(self):
        return self.UniSet.Anything

    def _get_quote(self):
        return []

    def _get_recurself(self):
        return self.family(RecurSelfFamily)

    def _get_relation(self):
        # relation is a representation category
        # We have the following representation objects:
        # 1. set of pairs with attribute dom, cod
        # 2. set of pairs with dom is cod
        # 3. fuop = func | op, string in ('==',..)
        # 4. (A, fuop), where A is a set
        # 5. (A, fuop, B), where A and B are sets
        #
        # A final object is 1.
        class RelationSpec:
            _isos_ = [
                ('1', 'paxb'),
                ('2', 'paxa'),
                ('3', 'defiop', 'fuop', ),
                ('4', 'defipair'),
                ('5', 'defitriple'),
            ]

            def _get_spec_1(self, e):
                return e.setof(e.cprod(e.Anything, e.Anything))

            def _get_spec_2(self, e):
                return (e.setof(e.cprod(e.Anything, e.Anything)))

            def _get_spec_3(self, e):
                return (e.boolean << (e.Anything, e.Anything) |
                        e.equals('<', '<=', '==', '!=', '>', '>=', 'in', 'not in', 'is', 'is not'))

            def _get_spec_4(self, e):
                return e.cprod(e.set, self._cat.fuop)

            def _get_spec_5(self, e):
                return e.cprod(e.set, self._cat.fuop, e.set)

            def _get__relop(self, e):
                return e.family(RelOpFamily)

            map_2_to_1 = id
            def map_3_to_4(self, e, fuop): return (e.Anything, fuop)
            def map_3_to_2(self, e, fuop): return self._relop(e.Anything, fuop)  # redundant
            def map_4_to_2(self, e, args): return self._relop(*args)
            def map_5_to_1(self, e, args): return self._relop(*args)

        return self.repcat(RelationSpec)

    def _get_relop(self):
        return self.relation.defiop.to.paxa

    def repcat(self, spec):
        return RepresentationCategory(self, spec)

    def _get_sequence(self):
        return self.family(SequenceFamily)

    def _get_set(self):
        return self.instance(self.UniSet.UniSet)

    def _get_set_of_disjoint_sets(self):
        def p(env, x):
            return env.forall_pairs(x, lambda env, a, b: a == b or a.disjoint(b),
                                    'a == b or a.disjoint(b)')
        return self.predicate(p, 'set of disjoint sets')

    def setcast(self, arg):
        if not isinstance(arg, self.UniSet.UniSet):
            arg = self.UniSet.convert(arg)
            arg = self.Doc.wrap(arg, self.Doc.callfunc(
                self.Doc.attribute(self._origin_, 'setcast'),
                arg))
        return arg

    def _get_setof(self):
        return self.powerset

    def _get__static_test_env(self):
        return self.mkTestEnv(None)

    def _get_synonyms(self):
        return self.family(SynonymsFamily)

    def _get_tupleform(self):
        return self.family(TupleformFamily)

    def _get_Type(self):
        return self.Use.Type

    def union_equals(self, set):
        return self.eg(self.attr('union', self.equals(set)),
                       self.powerset(set))

    def wrap_source_string(self, func, str):
        func._origin_ = self.Doc.source(str)
        return func