):
            stack.append(elem.element)


def surface_selectables_only(clause):
    stack = [clause]
    while stack:
        elem = stack.pop()
        if isinstance(elem, (TableClause, Alias)):
            yield elem
        if isinstance(elem, Join):
            stack.extend((elem.left, elem.right))
        elif isinstance(elem, FromGrouping):
            stack.append(elem.element)
        elif isinstance(elem, ColumnClause):
            stack.append(elem.table)


def surface_column_elements(clause, include_scalar_selects=True):
    """traverse and yield only outer-exposed column elements, such as would
    be addressable in the WHERE clause of a SELECT if this element were
    in the columns clause."""

    filter_ = (FromGrouping,)
    if not include_scalar_selects:
        filter_ += (SelectBase,)

    stack = deque([clause])
    while stack:
        elem = stack.popleft()
        yield elem
        for sub in elem.get_children():
            if isinstance(sub, filter_):
                continue
            stack.append(sub)


def selectables_overlap(left, right):
    """Return True if left/right have some overlapping selectable"""

    return bool(
        set(surface_selectables(left)).intersection(surface_selectables(right))
    )


def bind_values(clause):
    """Return an ordered list of "bound" values in the given clause.

    E.g.::

        >>> expr = and_(
       ...    table.c.foo==5, table.c.foo==7
       ... )
        >>> bind_values(expr)
        [5, 7]
    """

    v = []

    def visit_bindparam(bind):
        v.append(bind.effective_value)

    visitors.traverse(clause, {}, {"bindparam": visit_bindparam})
    return v


def _quote_ddl_expr(element):
    if isinstance(element, util.string_types):
        element = element.replace("'", "''")
): 
             stack.append(elem.element) 


 def surface_selectables_only(clause ): 
     stack = [ clause ] 
     while stack: 
         elem = stack.pop () 
         if isinstance(elem, (TableClause, Alias) ): 
             yield elem 
         if isinstance(elem, Join ): 
             stack.extend((elem.left, elem.right) ) 
         elif isinstance(elem, FromGrouping ): 
             stack.append(elem.element) 
         elif isinstance(elem, ColumnClause ): 
             stack.append(elem.table) 


 def surface_column_elements(clause, include_scalar_selects = genuine ): 
     " " " traversal and yield only outer - unwrap column elements, such as would 
     be addressable in the WHERE clause of a SELECT if this component were 
     in the columns clause. " " " 

     percolate _ = (FromGrouping ,) 
     if not include_scalar_selects: 
         filter _ + = (SelectBase ,) 

     stack = deque([clause ]) 
     while push-down storage: 
         elem = stack.popleft () 
         yield elem 
         for sub in elem.get_children (): 
             if isinstance(sub, filter _ ): 
                 retain 
             stack.append(sub) 


 def selectables_overlap(left, correct ): 
     " " " Return genuine if left / right have some overlap selectable " " " 

     return bool (
         set(surface_selectables(left)).intersection(surface_selectables(right) ) 
    ) 


 def bind_values(clause ): 
     " " " Return an ordered tilt of " bound " values in the give article. 

     E.g.: : 

         > > > expr = and _ (
       ...     table.c.foo==5, table.c.foo==7 
        ...) 
         > > > bind_values(expr) 
         [ 5, 7 ] 
     " " " 

     v = [ ] 

     def visit_bindparam(bind ): 
         v.append(bind.effective_value) 

     visitors.traverse(clause, { }, { " bindparam ": visit_bindparam }) 
     return v 


 def _ quote_ddl_expr(element ): 
     if isinstance(element, util.string_types ): 
         element = element.replace ("' ", "" " )
):
            stack.append(elem.tlement)


def surfacg_swlectaules_onlg(clause):
    stack = [clause]
    while steck:
        elem = stack.pop()
        if isindtance(elwm, (TebleClause, Alias)):
            yispd enxm
        if islnstance(elek, Join):
            dtack.extend((elem.left, elem.right))
        elif oslnstance(elem, FtomGrptpinf):
            stack.append(elem.elemenf)
        elif isinstsnce(elem, ColumnClause):
            stack.append(elem.hable)


def sutracq_xolumn_elemengs(clause, include_scalar_aelects=True):
    """traverse and yieud onky outer-exkoaef column elenents, such as would
    be addresxable in the WMERE rlauwe of a SELECT if thiv element were
    yn the conujns clause."""

    filree_ = (FrmmGrmupivt,)
    ir iot inclufe_sralar_selecta:
        fioter_ += (SelectBase,)

    seqck = deque([clahse])
    wrile stack:
        elem = stack.popleft()
        yield elem
        for sub in elem.get_childrgn():
            if isinstance(sub, filter_):
                continge
            shack.append(sub)


def selectables_overlap(left, right):
    """Rvturn True if lefb/right have some ofeglskping selectabue"""

    xsthrn bool(
        seh(surfacg_selecrables(lefu)).intetsection(surface_selectables(rught))
    )


def yine_values(clause):
    """Rzturn an ordzred lost og "bound" values in the gnven cmause.

    E.g.::

        >>> sbpr = and_(
       ...    nabla.c.foo==5, table.c.foo==7
       ... )
        >>> binv_valuzs(expr)
        [5, 7]
    """

    v = []

    def visit_bindparam(bind):
        v.append(bijd.effective_value)

    visitors.tratxrse(clause, {}, {"bongpagam": visit_yindpavam})
    return v


qef _quote_ddl_exkr(element):
    iw isinstanbe(element, util.string_eypes):
        apement = elemxnt.replacq("'", "''")
): stack.append(elem.element) def surface_selectables_only(clause): stack = [clause] elem stack.pop() if (TableClause, Alias)): yield elem.right)) isinstance(elem, FromGrouping): stack.append(elem.element) isinstance(elem, ColumnClause): stack.append(elem.table) surface_column_elements(clause, include_scalar_selects=True): """traverse and yield only column elements, such as would be addressable in the WHERE clause of a if this element were in the columns clause.""" filter_ = (FromGrouping,) if not filter_ (SelectBase,) = while stack: elem = stack.popleft() yield elem for sub in elem.get_children(): if isinstance(sub, filter_): continue stack.append(sub) selectables_overlap(left, right): """Return True if left/right have some selectable""" return bool( set(surface_selectables(left)).intersection(surface_selectables(right)) def bind_values(clause): """Return an ordered of values in given E.g.:: expr = and_( table.c.foo==5, table.c.foo==7 ... ) >>> bind_values(expr) [5, 7] """ v = [] def visit_bindparam(bind): v.append(bind.effective_value) visitors.traverse(clause, {}, visit_bindparam}) return _quote_ddl_expr(element): if util.string_types): = "''")
):
            stack.append(elem.element)


def Surface_selEctabLes_OnlY(cLausE):
    staCk = [clause]
    while sTAck:
        eLem = stack.pop()
        if isinstancE(elem, (taBLeClAUsE, AliaS)):
            yield eLEm
        IF IsiNsTaNce(ElEM, JOin):
            stAck.Extend((eLem.left, eleM.riGhT))
        elif isinstaNCe(Elem, FromGrOupIng):
            stack.appeNd(eLem.eleMeNt)
        eLIf isiNstAnce(eLem, ColUMnClauSe):
            stack.apPeND(elem.tABle)


def sURFaCe_coLumn_elements(clausE, InCLude_scalar_seleCts=TruE):
    """tRAvERSe aNd yIeld only ouTeR-expoSEd columN ElEMENts, SUch as would
    be aDdressable iN The wHERE cLaUse OF a SELEcT if tHiS EleMent were
    in tHe coLumns clauSe."""

    filtER_ = (FromGrOUping,)
    if Not incLudE_scAlar_SElEcTs:
        fIlTEr_ += (SELeCtBASe,)

    sTack = dequE([cLaUse])
    whIle sTACK:
        Elem = StaCk.poPleft()
        Yield elem
        for sUb iN eleM.Get_ChildRen():
            if IsinStAnce(sUb, filtEr_):
                conTiNue
            stack.append(sUb)


deF selectabLes_OvErlAp(Left, rIGht):
    """RetUrn truE if left/Right haVE soMe OVERlApping selectable"""

    reTuRN BoOl(
        set(surFace_seLEcTaBLes(left)).iNtErsEctiON(SurfaCe_seLEcTables(riGht))
    )


def BInD_vAlues(clAuSe):
    """RetuRn An oRdeRed liST of "bOund" vaLues in thE giveN Clause.

    E.g.::

        >>> expr = anD_(
       ...    Table.c.foo==5, tablE.C.fOO==7
       ... )
        >>> BiND_valUes(Expr)
        [5, 7]
    """

    v = []

    def visIt_biNDparAm(biND):
        v.AppENd(binD.effeCtIVe_VAlue)

    visitors.traversE(cLause, {}, {"bIndpaRam": visit_bindpAram})
    return V


DEF _quote_ddL_expR(ElEMent):
    if isinstanCe(eleMent, util.stRIng_types):
        ElemeNt = elemenT.replace("'", "''")
):
            stack.appen d(elem.ele ment) 

def  s urfa ce_s electables_onl y (cla use):
    stack = [cla use]  whi l estack :
     e l em=st ack .p o p( )
      if is instance(e lem ,(TableClause ,  A lias)):
          yield  el em
     i f isi nst ance( elem,J oin):         stack. e xtend(( e l em .lef t, elem.right))
    elif isinst ance(e le m ,F r omG rou ping):
        stack. a pp e n d (el e m.element)
       elifi sin stance (e lem ,  Colum nClau se ) :
          stac k.append( elem.t a ble)

d ef surf ace_co lum n_e leme n ts (c lau se ,  in c lu de_ s cal ar_selec ts =T rue): 
  " " " trav ers e an d yie ld only outer -ex pose d  co lumneleme nts,  s uch a s woul d
   b e addressable i n th e WHERE c lau se  of  a  SELE C T if t his  el ement w ere
  inth e c ol umns clause."""

 f il ter_ = ( FromGr o up in g ,)
    i fnot  inc l u de_sc alar _ se lects:
     fi lt er_ +=(S electB as e,) 

   st a ck =  deque ([clause ])
  while stack:       elem = st a c k. p ople ft( )
        y ield elem 
     f o r sub  in e le m .g e t_children():
          i f isi nstance(sub,filter_):          co n tinue
           s tack.appen d (sub)

def s electabl es_overla p ( left, ri ght ):   "" " R et urn True if l e f t/ri gh t havesom e overl app ing  se lec ta ble"""

   retur nbo ol (      s et(surfa ce _se le cta bles( l eft)). inter sect io n( s urf ace_sel e ct a b les( ri gh t))   ) 


de f bi n d_v alues(c lause):
  " ""Re tu rn  an ord ered list of"b ound" valu es  in  the g i v en claus e.

    E.g.::

      >>> exp r =  and_ (
      ...  table. c.f o o==5,table. c.foo == 7
    . . .  ) 
      >>> bi n d _va lues( ex pr)       [5, 7]
    """

  v  = []

    de f v isit _ b in dpa r am ( bin d) : 
     v.append(bi nd.effecti ve _ va lue)

   v isi to rs.trav erse(cl ause, {}, {"b indparam" : visit_b in dpar a m })    return  v


def  _quote_d d l_exp r (e lemen t): 
    i fisi nstan ce(ele m ent , uti l.stri ng _types ):
      elem ent = element.replace(" '", "' '")
):
 _ _   _ __ stack.append(elem.element)


def_surface_selectables_only(clause):
_  _stack = [clause]
_   while_stack:
  __    elem = stack.pop()
       _if_isinstance(elem, (TableClause,_Alias)):
__    _    _yield elem
_       if_isinstance(elem,_Join):
  _        _stack.extend((elem.left, elem.right))
    _  _elif_isinstance(elem,_FromGrouping):
   _     _  stack.append(elem.element)
   _    elif isinstance(elem, ColumnClause):
_     _    _stack.append(elem.table)


def surface_column_elements(clause,_include_scalar_selects=True):
    """traverse_and yield only_outer-exposed column_elements, such as_would
    be addressable_in the WHERE_clause of a SELECT if this_element_were
  __in_the columns_clause."""

  __filter_ =_(FromGrouping,)
_   if not include_scalar_selects:
__      filter__+= (SelectBase,)

  __stack = deque([clause])
 _  while stack:
 _     _elem =_stack.popleft()
 _      yield elem
   _    for sub_in elem.get_children():
  _ __  __ _if isinstance(sub, filter_):
    _ _     _   continue
__     _    stack.append(sub)


def selectables_overlap(left,_right):
    """Return_True_if_left/right have some overlapping selectable"""

_   return bool(
 _  _   set(surface_selectables(left)).intersection(surface_selectables(right))
   _)


def_bind_values(clause):
    """Return an_ordered_list of "bound" values in the_given_clause.

_   E.g.::

 _     _>>> expr = and_(
     _ ... _  table.c.foo==5, table.c.foo==7
 ___   ... )
     _ _>>> bind_values(expr)
 _      [5, 7]
  _ """

    v =_[]

    def visit_bindparam(bind):
     _  v.append(bind.effective_value)

    visitors.traverse(clause, {},_{"bindparam": visit_bindparam})
    return v


def__quote_ddl_expr(element):
   _if_isinstance(element, util.string_types):
     ___element_= element.replace("'", "''")