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