A try on mapping viz

karavana/karavana.py

+from __future__ import annotations
+
+import collections.abc as abcs
+from dataclasses import dataclass, field
+from enum import Enum, auto
+from typing import Any, Optional
+
+class Display(Enum):
+    COLLECTION = auto()
+    
+@dataclass
+class Node:
+    value: Display
+    children: Optional[Node] = field(default_factory=list)
+
+    def add_child(self, child):
+        self.children.append(child)
+
+@dataclass
+class ConnectedNode:
+    lhs: Any
+    rhs: Any
+
+class Viz:
+    typeregs = {}
+
+    def visit(self, obj):
+        for abc, viz in self.typeregs.items():
+            if isinstance(obj, abc):
+                return viz(self, obj)
+        else:
+            return obj
+
+    @classmethod
+    def register(cls, protocol, attr):
+        def wrapper(func):
+            cls.typeregs[getattr(protocol, attr)] = func
+            return func
+
+        return wrapper
+
+
+@Viz.register(abcs, "Mapping")
+def mapping(self, obj):
+    node = Node(Display.COLLECTION)
+    for key, value in obj.items():
+        child = ConnectedNode(self.visit(key), self.visit(value))
+        node.add_child(child)
+    return node
+
+viz = Viz()
+node = viz.visit({1: 1, 2: 2, 3: {1: 2}})
+print(node)