avoid holes in forks, update intro

src/kyupy/circuit.py

@@ -176,7 +176,11 @@ class Line:
         To keep the indices consecutive, the line with the highest index within the circuit
         will be assigned the index of the removed line.
         """
-        if self.driver is not None: self.driver.outs[self.driver_pin] = None
+        if self.driver is not None:
+            self.driver.outs[self.driver_pin] = None
+            if self.driver.kind == '__fork__':  # squeeze outputs
+                del self.driver.outs[self.driver_pin]
+                for i, l in enumerate(self.driver.outs): l.driver_pin = i
         if self.reader is not None: self.reader.ins[self.reader_pin] = None
         if self.circuit is not None: del self.circuit.lines[self.index]
         self.driver = None
@@ -564,6 +568,7 @@ class Circuit:
         from graphviz import Digraph
         dot = Digraph(format=format, graph_attr={'rankdir': 'LR', 'splines': 'true'})
 
+        s_dict = dict((n, i) for i, n in enumerate(self.s_nodes))
         node_level = np.zeros(len(self.nodes), dtype=np.uint32)
         level_nodes = defaultdict(list)
         for n, lv in self.topological_order_with_level():
@@ -576,7 +581,8 @@ class Circuit:
                 for n in level_nodes[lv]:
                     ins = '|'.join([f'<i{i}>{i}' for i in range(len(n.ins))])
                     outs = '|'.join([f'<o{i}>{i}' for i in range(len(n.outs))])
-                    s.node(name=str(n.index), label = f'{{{{{ins}}}|{n.index}\n{n.kind}\n{n.name}|{{{outs}}}}}', shape='record')
+                    io = f' [{s_dict[n]}]' if n in s_dict else ''
+                    s.node(name=str(n.index), label = f'{{{{{ins}}}|{n.index}{io}\n{n.kind}\n{n.name}|{{{outs}}}}}', shape='record')
 
         for l in self.lines:
             driver, reader = f'{l.driver.index}:o{l.driver_pin}', f'{l.reader.index}:i{l.reader_pin}'