stl_treemap.policies

  1"""Node data access policies for sets, maps, and value iteration."""
  2
  3from __future__ import annotations
  4
  5from abc import ABC, abstractmethod
  6
  7from stl_treemap.tree_node import TreeNode
  8
  9
 10class PolicyInterface[K, V](ABC):
 11    """@private Interface for node data access policies."""
 12
 13    @abstractmethod
 14    def fetch(self, n: TreeNode[K, V]) -> K | V | tuple[K, V]:
 15        """Return data from the specified node."""
 16
 17    @abstractmethod
 18    def copy(self, dst: TreeNode[K, V], src: TreeNode[K, V]) -> None:
 19        """Copy data from one node to another."""
 20
 21    @abstractmethod
 22    def to_string(self, node: TreeNode[K, V]) -> str:
 23        """Return string representation of the node."""
 24
 25
 26class KeyOnlyPolicy[K, V](PolicyInterface[K, V]):
 27    """@private Used by sets."""
 28
 29    def fetch(self, n: TreeNode[K, V]) -> K:
 30        """
 31        Return key data from the specified node.
 32
 33        Args:
 34            n: Node to inspect.
 35
 36        Returns:
 37            Node's key.
 38
 39        """
 40        return n.key
 41
 42    def copy(self, dst: TreeNode[K, V], src: TreeNode[K, V]) -> None:
 43        """
 44        Copy key data from one node to another.
 45
 46        Args:
 47            dst: Destination node.
 48            src: Source node.
 49
 50        """
 51        dst.key = src.key
 52
 53    def to_string(self, node: TreeNode[K, V]) -> str:
 54        """
 55        Return string representation of the provided node.
 56
 57        Args:
 58            node: Node to serialize.
 59
 60        Returns:
 61            String representation of the key.
 62
 63        """
 64        return str(node.key)
 65
 66
 67class KeyValuePolicy[K, V](PolicyInterface[K, V]):
 68    """@private Used by maps."""
 69
 70    def fetch(self, n: TreeNode[K, V]) -> tuple[K, V]:
 71        """
 72        Return key-value data from the specified node.
 73
 74        Args:
 75            n: Node to inspect.
 76
 77        Returns:
 78            Tuple of key and value.
 79
 80        """
 81        return (n.key, n.value)
 82
 83    def copy(self, dst: TreeNode[K, V], src: TreeNode[K, V]) -> None:
 84        """
 85        Copy key-value data from one node to another.
 86
 87        Args:
 88            dst: Destination node.
 89            src: Source node.
 90
 91        """
 92        dst.key = src.key
 93        dst.value = src.value
 94
 95    def to_string(self, node: TreeNode[K, V]) -> str:
 96        """
 97        Generate string representation of the node.
 98
 99        Args:
100            node: Node to serialize.
101
102        Returns:
103            String representation of key-value pair.
104
105        """
106        return f"{node.key}:{node.value}"
107
108
109class ValueOnlyPolicy[K, V](PolicyInterface[K, V]):
110    """@private Used for iteration through values of a map."""
111
112    def fetch(self, n: TreeNode[K, V]) -> V:
113        """
114        Return value data from the specified node.
115
116        Args:
117            n: Node to inspect.
118
119        Returns:
120            Node's value.
121
122        """
123        return n.value
124
125    def copy(self, dst: TreeNode[K, V], src: TreeNode[K, V]) -> None:
126        """
127        Copy value data from one node to another.
128
129        Args:
130            dst: Destination node.
131            src: Source node.
132
133        """
134        dst.value = src.value
135
136    def to_string(self, node: TreeNode[K, V]) -> str:
137        """
138        Return string representation of the node.
139
140        Args:
141            node: Node to serialize.
142
143        Returns:
144            String representation of node's value.
145
146        """
147        return str(node.value)