some more work

mason.py

@@ -7,7 +7,18 @@ class System:
             self.nodes.append(Node(self, self.nextname()))
     
     def findtransfer(self, source, sink):
-        def findpaths():
+        def concat(*args):
+            res = []
+            map(res.extend, args)
+            
+        
+        def findpaths(crnt, path, target):
+            if crnt is target:
+                return Path(path + [crnt])
+            nxt = [i.target for i in crnt.connections if i.target not in deadnodes]
+            newpath = path + [crnt]
+            return [findpaths(i, newpath, sink) for i in nxt]
+            
             
         virtual = False
         if not source.issource():
@@ -19,19 +30,19 @@ class System:
         paths = []
         loops = []
         
-    
+    #create automatic node names
     def nextname(self):
         pass
     
     #returns True if there are no connections pointing to the node#returns True if there are no connections pointing to the node
     def issource(self, node):
-        if not isinstance(node, Node):
+        if not isinstance(node, (Node, Connection)):
-            raise TypeError('argument must be a Node')
+        elif for i in self.nodes:
-        for i in self.nodes:
             for j in i.connections:
                 if node is j[1]:
                     return False
         return True
+            raise TypeError('argument must be a Node or Connection')
         
     #returns True if there are no connections starting from the node
     def issink(self, node):
@@ -46,7 +57,7 @@ class Node:
         self.connections = []
     
     def connect(target, transfer):
-        self.connections.append((taget, transfer))
+        self.connections.append((target, transfer))
     
     #returns True if there are no connections pointing to the node
     def issource(self):
@@ -56,10 +67,22 @@ class Node:
     def issink(self):
         return self.connections == []
 
+#I'm still not sure whether I want to use this or just tuples
 class Connection:
-    def __init__(self, target, gain):
+    def __init__(self, origin, target, gain):
-        
+        self.origin = origin
+        self.target = target
+        self.gain = gain
 
-class Loop:
+class NodeLink:
-    def __init__(self):
+    def __init__(self, nodes):
-        pass
+        self.nodes = nodes
+    
+    def contains(self, node):
+        return node in self.nodes
+
+class Path(NodeLink):
+    pass
+
+class Loop(NodeLink):
+    pass