except ZeroDivisionError:
return None
return ret
res = reduce(F, args, z)
return res
eval = unarg(eval_expr)
number = sometok('number') >> make_number
name = sometok('name') >> make_name
string = sometok('string') >> make_string
func = sometok('func') >> make_func
value = number | name | string
makeop = lambda s, f: op(s) >> const(f)
add = makeop('+', (ets.add, operator.add))
sub = makeop('-', (ets.sub, operator.sub))
mul = makeop('*', (ets.mul, operator.mul))
div = makeop('/', (ets.div, operator.div))
mul_op = mul | div
add_op = add | sub
args = fwd()
factor = fwd()
primary = value
call = func + op_('(') + args + op_(')') >> exec_func
term = factor + many(mul_op + factor ) >> eval
expr = term + many(add_op + term ) >> eval
Spec('number', r'-?(\.[0-9]+)|([0-9]+(\.[0-9]*)?)'),
Spec('string', r'"[^"]*"'), # '\"' escapes are ignored
]
useless = ['comment', 'newline', 'space']
t = make_tokenizer(specs)
return [x for x in t(str) if x.type not in useless]
id = sometoks(['name', 'number', 'string'])
make_graph_attr = lambda args: DefAttrs(u'graph', [Attr(*args)])
make_edge = lambda x, xs, attrs: Edge([x] + xs, attrs)
node_id = memoize(id) # + maybe(port)
a_list = (
id +
maybe(op_('=') + id) +
skip(maybe(op(',')))
>> unarg(Attr))
attr_list = (
many(op_('[') + many(a_list) + op_(']'))
>> flatten)
attr_stmt = (
(n('graph') | n('node') | n('edge')) +
attr_list
>> unarg(DefAttrs))
graph_attr = id + op_('=') + id >> make_graph_attr
node_stmt = node_id + attr_list >> unarg(Node)
# We use a fwd() because of circular definitions like (stmt_list -> stmt ->
# subgraph -> stmt_list)
subgraph = fwd()
edge_rhs = skip(op('->') | op('--')) + (subgraph | node_id)
edge_stmt = (
