| 23 | 23 | |
| 24 | 24 | |
| 25 | 25 | class Graph: |
| 26 | """ |
| 27 | A class representing a graph DSL that can parse graph data. |
| 28 | |
| 29 | The graph data is a list of items, where each item is a tuple. |
| 30 | The first element of the tuple indicates the type of item (NODE, EDGE, or ATTR). |
| 31 | """ |
| 32 | |
| 26 | 33 | def __init__(self, data: list | None = None): |
| 27 | | pass |
| 34 | """ |
| 35 | Initialize a Graph with optional data. |
| 36 | |
| 37 | Args: |
| 38 | data: A list of graph items (tuples) or None for an empty graph. |
| 39 | |
| 40 | Raises: |
| 41 | TypeError: If data is not a list or if any item is malformed. |
| 42 | ValueError: If an unknown item type is encountered. |
| 43 | """ |
| 44 | # Edge Case: Data is None, initialize empty graph |
| 45 | if data is None: |
| 46 | self.attrs = {} |
| 47 | self.nodes = [] |
| 48 | self.edges = [] |
| 49 | return |
| 50 | |
| 51 | # Edge Case: Data is not a list |
| 52 | if not isinstance(data, list): |
| 53 | raise TypeError("Graph data malformed") |
| 54 | |
| 55 | self.attrs = {} |
| 56 | self.nodes = [] |
| 57 | self.edges = [] |
| 58 | |
| 59 | # Process each item in the data |
| 60 | for item in data: |
| 61 | # Edge Case: Item is not a tuple |
| 62 | if not isinstance(item, tuple): |
| 63 | raise TypeError("Graph item malformed") |
| 64 | |
| 65 | # Edge Case: Empty tuple |
| 66 | if len(item) == 0: |
| 67 | raise TypeError("Graph item malformed") |
| 68 | |
| 69 | item_type = item[0] |
| 70 | |
| 71 | # Edge Case: Unknown item type |
| 72 | if item_type not in [NODE, EDGE, ATTR]: |
| 73 | raise ValueError("Unknown item") |
| 74 | |
| 75 | # Process attribute |
| 76 | if item_type == ATTR: |
| 77 | # Edge Case: Attribute tuple doesn't have exactly 3 elements |
| 78 | if len(item) != 3: |
| 79 | raise TypeError("Graph item malformed") |
| 80 | |
| 81 | key, value = item[1], item[2] |
| 82 | self.attrs[key] = value |
| 83 | |
| 84 | # Process node |
| 85 | elif item_type == NODE: |
| 86 | # Edge Case: Node tuple doesn't have exactly 3 elements |
| 87 | if len(item) != 3: |
| 88 | raise TypeError("Graph item malformed") |
| 89 | |
| 90 | name, attrs = item[1], item[2] |
| 91 | # Edge Case: Node attributes is not a dict |
| 92 | if not isinstance(attrs, dict): |
| 93 | raise TypeError("Graph item malformed") |
| 94 | |
| 95 | self.nodes.append(Node(name, attrs)) |
| 96 | |
| 97 | # Process edge |
| 98 | elif item_type == EDGE: |
| 99 | # Edge Case: Edge tuple doesn't have exactly 4 elements |
| 100 | if len(item) != 4: |
| 101 | raise TypeError("Graph item malformed") |
| 102 | |
| 103 | src, dst, attrs = item[1], item[2], item[3] |
| 104 | # Edge Case: Edge attributes is not a dict |
| 105 | if not isinstance(attrs, dict): |
| 106 | raise TypeError("Graph item malformed") |
| 107 | |
| 108 | self.edges.append(Edge(src, dst, attrs)) |
| 109 | |
| 110 | # Handled Edge Cases: Data is None, data is not a list, item is not a tuple, |
| 111 | # empty tuple, unknown item type, attribute tuple length != 3, |
| 112 | # node tuple length != 3, node attributes not a dict, |
| 113 | # edge tuple length != 4, edge attributes not a dict |