import tpg


class Leaf(object):
    def __init__(self, label):
        self.label = label

    def __str__(self):
        return self.label

class Internal(object):
    def __init__(self, label, subtrees):
        self.label = label
        self.subtrees = subtrees

    def __str__(self):
        return '(%s)%s' % (','.join(str(st) for st in self.subtrees),self.label)


class Branch(object):
    def __init__(self, subtree, length):
        self.subtree = subtree
        self.length = length

    def __str__(self):
        return '%s:%s' % (str(self.subtree),str(self.length))

class Parser(tpg.Parser):
    r"""

    separator space	'\s+' 							;

    token label		'[^,:;() \t\n]+' ;

    START/tree ->
    	Subtree/tree ';'
    ;

    Subtree/tree ->
    	Internal/tree
      | Leaf/tree
    ;

    Leaf/leaf ->
    	Name/name				$ leaf = Leaf(name)
    ;

    Internal/tree ->
    	'\(' BranchList/st '\)' Name/n		$ tree = Internal(n,st)
    ;

    BranchList/blist ->
        Branch/b (',' BranchList/bl $ blist = bl+[b] $ )+
      | Branch/branch				$ blist = [branch]
    ;

    Branch/branch ->
    	Subtree/st Length/l			$ branch = Branch(st,l)
    ;

    Name/name ->
    	label/name
      | Empty					$ name = ""
    ;

    Length/length ->
    	':' Number/length
      | Empty					$ length = 0
    ;

    Number/n ->
        label/l					$ n = float(l)
    ;

    Empty -> ;


    """