default NamedTuple arguments

Author: mvcisback

aiger/aig.py

@@ -67,11 +67,11 @@ def _is_const_true(node):
 
 
 class AIG(NamedTuple):
-    inputs: FrozenSet[str]  # TODO: use internal names to make relabels fast.
-    node_map: FrozenSet[Tuple[str, Node]]
-    latch_map: FrozenSet[Tuple[str, Node]]
-    latch2init: FrozenSet[Tuple[str, Node]]
-    comments: Tuple[str]
+    inputs: FrozenSet[str] = frozenset()
+    node_map: FrozenSet[Tuple[str, Node]] = frozenset()
+    latch_map: FrozenSet[Tuple[str, Node]] = frozenset()
+    latch2init: FrozenSet[Tuple[str, Node]] = frozenset()
+    comments: Tuple[str] = ()
 
     def __repr__(self):
         return repr(self._to_aag())

aiger/common.py

@@ -32,8 +32,6 @@ def and_gate(inputs, output=None):
 
     return aig.AIG(
         inputs=frozenset(inputs),
-        latch_map=frozenset(),
-        latch2init=frozenset(),
         node_map=frozenset(((output, _map_tree(inputs, f=_and)), )),
         comments=(' and '.join(inputs), ))
 
@@ -61,8 +59,6 @@ def parity_gate(inputs, output=None):
 
     return aig.AIG(
         inputs=frozenset(inputs),
-        latch_map=frozenset(),
-        latch2init=frozenset(),
         node_map=frozenset(((output, _map_tree(inputs, f=_xor)), )),
         comments=(' xor '.join(inputs), ))
 
@@ -73,14 +69,12 @@ def identity(inputs, outputs=None):
 
     return aig.AIG(
         inputs=frozenset(inputs),
-        latch_map=frozenset(),
-        latch2init=frozenset(),
         node_map=frozenset(zip(outputs, map(aig.Input, inputs))),
         comments=('identity', ))
 
 
 def empty():
-    return identity([])
+    return aig.AIG()
 
 
 def _inverted_input(name):
@@ -95,8 +89,6 @@ def bit_flipper(inputs, outputs=None):
 
     return aig.AIG(
         inputs=frozenset(inputs),
-        latch_map=frozenset(),
-        latch2init=frozenset(),
         node_map=frozenset(zip(outputs, map(_inverted_input, inputs))),
         comments=('~', ))
 
@@ -107,19 +99,13 @@ def _const(val):
 
 def source(outputs):
     return aig.AIG(
-        inputs=frozenset(),
-        latch_map=frozenset(),
-        latch2init=frozenset(),
         node_map=frozenset((k, _const(v)) for k, v in outputs.items()),
         comments=('source', ))
 
 
 def sink(inputs):
     return aig.AIG(
         inputs=frozenset(inputs),
-        latch_map=frozenset(),
-        latch2init=frozenset(),
-        node_map=frozenset(),
         comments=('sink', ))
 
 
@@ -132,8 +118,6 @@ def tee_output(name, renames):
 
     return aig.AIG(
         inputs=frozenset(outputs),
-        latch_map=frozenset(),
-        latch2init=frozenset(),
         node_map=frozenset.union(*starmap(tee_output, outputs.items())),
         comments=('T', ))